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Inlet Plugs for Jaguar Cowl on a Tiger
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Dan.Schmitz(at)calix.com
Guest

Posted: Thu May 24, 2012 11:47 am Post subject: Inlet Plugs for Jaguar Cowl on a Tiger

All that work might be worth it to find out Iâ€™m going +/- 2 knots for real.  5 knots should be hard to miss, even if Iâ€™m being kinda sloppy.  I do most speed  tests solo starting with full tanks.  My usual concern is up/down drafts.  For â€œsome period of timeâ€ generally a few minutes, I have to be able to fly hands off at a stable speed and no altitude changes.  If Iâ€™m doing a GPS test, I do sometimes have to bump  the ailerons to keep an exact track.  My aileron trim isnâ€™t that perfect.  If I detect any up/down drafts any time during the flight, I discard the entire days numbers. 

  

All my temperature gauges, including OAT, are Electronics International. 

  

Dan 

  

    

 I always set for best power by the Lycoming book method and then check it by adjusting the mixture with the prop set in manual mode to ensure maximum rpm. I fly at equivalent density altitude calculated on the fly by the Garmin 430 and  also do the compass ordinates and formulas for wind correction. I try and fly at the same OAT. Seems to make a difference even though I am flying at equivalent DAs. I always have the same amount of fuel on board, have a freshly cleaned and waxed plane and  prop and ensure the same CG. The flaps have to be in exactly the same position, whatever that was last time. A difference of even 1 deg up or down will effect your speed. This is hard to get consistent. If a trim tab was touched between tests it will also  affect your results. I always repeat the test 3 or 4 times until the numbers repeat. If they don't repeat then something is changing and I quit and try another day. It's really tedious to get good numbers but it's another excuse to go fly;) Food for thought,  the air speed needle is about 2 kts wide, so it's really hard to detect a 1-2 knot speed increase. Thats one reason why I record indicated airspeed, true air speed and ground speed from the gps on every flight test. The last 2 are digital from the Garmin. Another  uncanny result I continue to experience is that flying directly with the wind almost always gets me 2 more knots than flying directly into the wind. I think David Fletcher told me this was his experience also. That's not supposed to be that way. Weird huh? 

  

  

  

Something to think about is that if you are getting about the same speed as before Jaguar but have lower CHTs then you are in effect going faster. That energy is just being lost by the increased cooling drag. Maybe an area worth experimenting  with;) 

  

  

  

My after Jag experience is that the speed is about the same but the cooling is better by about 45 deg F. My plane was already fast so the typical speed increase from the Jag wouldn't be as likely for it. If  I can get my CHTs back to 380s from the now 330s by cooling drag reduction, I think I might see that 5-7 kts increase I had hoped for. 

  

BTW, what brand gauges are you using for the temperatures? 

  

Regards, 

  

Ned 

  

  

  

On May 24, 2012, at 7:04 AM, Dan Schmitz <Dan.Schmitz(at)calix.com (Dan.Schmitz(at)calix.com)> wrote: 

  	  Quote: 	
		    

If IAS is meaningless, then computing TAS off of IAS is a pointless exercise.  I was comparing IAS of density altitude to IAS of the same density altitude.   The TAS calculations will work out to be the same in either case.  Note that I completely ignored the IAS in a number of test runs where I simply used GPS ground speed in 3 directions to compute a TAS using some fun formulas.  The numbers all come out to â€œno  real changeâ€. 

  

Now, by the argument that a prop turning X RPM at Y density altitude will see no speed change even as there are drag reductionsâ€¦um counter-intuitive, but my  high altitude tests up to 13,300â€™ with new cowl so far show no changes either.  Of course, the problem with my high density altitude tests then are they are at â€œfullâ€ engine power, I lean for highest RPM in a speed test at higher altitudes.  I donâ€™t imagine  my engine is doing its best with a cylinder being broken in (maybe) and running on mineral oil.  So thereâ€™s power Iâ€™m not getting yet.  Do most Grummans see a 5 knot speedup after breaking in and switching to normal oil?   

  

Dan Schmitz 

Tiger 4518B 

KASH 

     

From: owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com) [mailto:owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com)] On Behalf Of Gary Vogt

 Sent: Thursday, May 24, 2012 12:37 AM

 To: teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)

 Subject: Re: TeamGrumman-List: Inlet Plugs for Jaguar Cowl on a Tiger 

 

 

    

Dan, I really can't tell from here what is with your plane.  I've installed 7 Jaguar Cowlings and not one was slower.  Do you know how to compute True Airspeed?   Indicated airspeed is meaningless. 

  

  

       

 

From: Dan Schmitz <Dan.Schmitz(at)calix.com (Dan.Schmitz(at)calix.com)>

 To: "teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)" <teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)> 

 Sent: Wednesday, May 23, 2012 11:55 AM

 Subject: RE: TeamGrumman-List: Inlet Plugs for Jaguar Cowl on a Tiger 

 

      

Just this morning, I computed the density altitudes for a test run last Saturday.  It was a perfect calm day for speed testing with light winds coming off the ocean (no  mountain waves).  But then I forgot most of my past results are on a my airplaneâ€™s pocket PC back home.  I donâ€™t think my new numbers are much different maybe one or two knots better.  I dropped in on Brooks with the hopes of talking to him about making some  of the adjustments you noted but he was off with his kids. 

  

  

  

Do you think if I plug the hole in the one baffle and close the gap in the top center with some rubber, will that make any difference? 

  

  

  

Dan Schmitz 

  

Tiger 4518B 

  

KASH 

  

  

  

  

     

From: owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com) [mailto:owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com)] On Behalf Of Gary Vogt

 Sent: Wednesday, May 23, 2012 1:50 PM

 To: teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)

 Subject: Re: TeamGrumman-List: Inlet Plugs for Jaguar Cowl on a Tiger 

 

 

  

  

    

Any updates on your cowl . .  . speed?  CHTs? 

 

   

  

 

 

 

 

  	  Quote:

Dan.Schmitz(at)calix.com
Guest

Posted: Thu May 24, 2012 12:14 pm Post subject: Inlet Plugs for Jaguar Cowl on a Tiger

Me too (wish I was closer).  Iâ€™ll be at Oshkosh for the AYA convention.  Anyway what kind of speeds were you getting pre and post Jaguar?  My best speeds both  pre and post are 138 knots.  Did your other planes go from 133 to 138?  Iâ€™ve always been able to run a bit over 2700 RPM at 8000â€™ and thatâ€™s with a 64â€ pitch sensenich.  Right about 9000â€™ DA is where full throttle equals 2700 RPM (strobe checked, not tach),  again both before and after the new cowl. 

  

Dan 

     

From: owner-teamgrumman-list-server(at)matronics.com [mailto:owner-teamgrumman-list-server(at)matronics.com] On Behalf Of Gary Vogt

 Sent: Thursday, May 24, 2012 1:29 PM

 To: teamgrumman-list(at)matronics.com

 Subject: Re: TeamGrumman-List: Inlet Plugs for Jaguar Cowl on a Tiger 

 

 

    

Well, Dan, 

  

  

  

On N3752W, the only change to the plane was the cowling.  Right out of the hangar it was 5 knots (TAS) faster than the stock cowling at altitudes between  1500 feet and 5500 feet and 2700 rpm.  It was also easier to run past 2700 rpm at 8000 feet.  So, I don't know what to tell you.   

  

  

  

When I installed the very first one on N119ST, it was 9 knots (TAS) faster.  On my plane with a 65-63-61 prop, it was 10 knots (TAS) faster.  Both at 2700  rpm.  My old cowling, however, didn't fit well, was debonding and patched all over.   

  

  

  

I wish you were closer.   

  

  

  

Gary 

  

  

       

 

From: Dan Schmitz <Dan.Schmitz(at)calix.com (Dan.Schmitz(at)calix.com)>

 To: "teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)" <teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)> 

 Sent: Thursday, May 24, 2012 5:04 AM

 Subject: RE: TeamGrumman-List: Inlet Plugs for Jaguar Cowl on a Tiger 

 

      

If IAS is meaningless, then computing TAS off of IAS is a pointless exercise.  I was comparing IAS of density altitude to IAS of the same density altitude.  The TAS calculations  will work out to be the same in either case.  Note that I completely ignored the IAS in a number of test runs where I simply used GPS ground speed in 3 directions to compute a TAS using some fun formulas.  The numbers all come out to Ã¢â‚¬Å“no real changeÃ¢â‚¬ï¿½. 

  

  

  

Now, by the argument that a prop turning X RPM at Y density altitude will see no speed change even as there are drag reductionsÃ¢â‚¬Â¦um counter-intuitive, but my high altitude  tests up to 13,300Ã¢â‚¬â„¢ with new cowl so far show no changes either.  Of course, the problem with my high density altitude tests then are they are at Ã¢â‚¬Å“fullÃ¢â‚¬ï¿½  engine power, I lean for highest RPM in a speed test at higher altitudes.  I donÃ¢â‚¬â„¢t imagine my engine is doing its best with a cylinder being broken in (maybe) and running on mineral oil.  So thereÃ¢â‚¬â„¢s power IÃ¢â‚¬â„¢m not getting yet.  Do most Grummans see a  5 knot speedup after breaking in and switching to normal oil?   

  

  

  

Dan Schmitz 

  

Tiger 4518B 

  

KASH 

  

  

     

From: owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com) [mailto:owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com)] On Behalf Of Gary Vogt

 Sent: Thursday, May 24, 2012 12:37 AM

 To: teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)

 Subject: Re: TeamGrumman-List: Inlet Plugs for Jaguar Cowl on a Tiger 

 

 

  

  

    

Dan, I really can't tell from here what is with your plane.  I've installed 7 Jaguar Cowlings and not one was slower.  Do you know how to compute True Airspeed?  Indicated airspeed is meaningless. 

 

   

  

 

       

  

From: Dan Schmitz <Dan.Schmitz(at)calix.com (Dan.Schmitz(at)calix.com)>

 To: "teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)" <teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)> 

 Sent: Wednesday, May 23, 2012 11:55 AM

 Subject: RE: TeamGrumman-List: Inlet Plugs for Jaguar Cowl on a Tiger 

 

  

  

      

Just this morning, I computed the density altitudes for a test run last Saturday.  It was a perfect calm day for speed testing with light winds coming off the ocean (no  mountain waves).  But then I forgot most of my past results are on a my airplaneÃ¢â‚¬â„¢s pocket PC back home.  I donÃ¢â‚¬â„¢t think my new numbers are much different maybe one or two knots better.  I dropped in on Brooks with the hopes of talking to him about making  some of the adjustments you noted but he was off with his kids. 

 

   

  

 

   

Do you think if I plug the hole in the one baffle and close the gap in the top center with some rubber, will that make any difference? 

 

   

  

 

   

Dan Schmitz 

 

   

Tiger 4518B 

 

   

KASH 

 

   

  

 

   

  

 

      

From: owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com) [mailto:owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com)] On Behalf Of Gary Vogt

 Sent: Wednesday, May 23, 2012 1:50 PM

 To: teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)

 Subject: Re: TeamGrumman-List: Inlet Plugs for Jaguar Cowl on a Tiger 

 

 

 

   

  

 

     

Any updates on your cowl . .  . speed?  CHTs? 

 

 

    

  

 

 

 

 

 

 

  

  

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dmwhite(at)e3ra.com
Guest

Posted: Thu May 24, 2012 8:26 pm Post subject: Inlet Plugs for Jaguar Cowl on a Tiger

I will have some better data after this weekend due to another high altitude trip.Â  Right now, I would say that I am betting about 5 to 7 knots (versus Lopresti nose bowl) in cruise at 10k.Â  I think it is a little less down low but try not to firewall it down there so am not too sure.Â  What I really enjoy are the lower and more even CHTs â€“ Iâ€™m easily 30 degrees cooler.Â  I think my previous baffles left something to be desired so part of that is the new baffles but certainly not all.

 

Dean White (Tiger N81166)

Edmonds, WA 98026

dmwhite(at)e3ra.com



 

From: owner-teamgrumman-list-server(at)matronics.com [mailto:owner-teamgrumman-list-server(at)matronics.com] On Behalf Of Gary Vogt

Sent: Wednesday, May 23, 2012 9:44 PM

To: teamgrumman-list(at)matronics.com

Subject: Re: Inlet Plugs for Jaguar Cowl on a Tiger

 

Dean, what is your experience with the cowling?



 

From: Dean White <dmwhite(at)e3ra.com (dmwhite(at)e3ra.com)>

To: teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com) 

Sent: Wednesday, May 23, 2012 7:12 PM

Subject: RE: Inlet Plugs for Jaguar Cowl on a Tiger



 

NOT!



 



Dean White (Tiger N81166)



Edmonds, WA 98026



dmwhite(at)e3ra.com (dmwhite(at)e3ra.com)

 



From: owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com) [mailto:owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com)] On Behalf Of Brian Hausknecht

Sent: Wednesday, May 23, 2012 5:41 PM

To: teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)

Subject: Re: Inlet Plugs for Jaguar Cowl on a Tiger



 



So Gary's cowling decreases speed?



Brian Hausknecht

bhauskne(at)gmail.com (bhauskne(at)gmail.com)

www.brianflys.net

www.brianflys.com[/url]

[u]Dan.Schmitz(at)calix.com (Dan.Schmitz(at)calix.com)> 

[b]Sender: owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com) 

Date: Thu, 24 May 2012 00:30:58 +0000

To: teamgrumman-list(at)matronics.com<teamgrumman-list(at)matronics.com ([email]teamgrumman-list(at)matronics.com%3cteamgrumman-list(at)matronics.com[/email])>

ReplyTo: teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)

Subject: RE: Inlet Plugs for Jaguar Cowl on a Tiger

 

Ok, went through and comp= ared numbers.  My plane isnâ€™t any faster than last year.  M= aybe a knot slower actually.  Thatâ€™s comparing IAS before and af= ter adjusted for density altitude as well as GPS derived airspeed (by flying three dire= ctions) come out about the same as well.  Below 9000â€™ I kept the= prop at 2700 RPM (using external monitor not tach) so engine power isnR= 17;t a variable.  At higher altitudes I used whatever full throttle got me and in both cases RPMs were generally the same at com= parable density altitudes.



  <= /p> 



  <= /p> 



Dan



  <= /p> 



  <= /p> 



From: owner-te= amgrumman-list-server(at)matronics.com (amgrumman-list-server(at)matronics.com) [mailto:owner-teamgrumman-list-server(at)m= atronics.com ([email]owner-teamgrumman-list-server(at)m=%20atronics.com[/email])] On Behalf Of Dan Schmitz

Sent: Wednesday, May 23, 2012 2:56 PM

To: teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)

Subject: RE: Inlet Plugs for Jaguar Cowl on a Tige= r



 



Just this morning, I comp= uted the density altitudes for a test run last Saturday.  It was a per= fect calm day for speed testing with light winds coming off the ocean (no mountain waves).  But then I forgot most of my past results= are on a my airplaneâ€™s pocket PC back home.  I donâ€™t thin= k my new numbers are much different maybe one or two knots better.  I = dropped in on Brooks with the hopes of talking to him about making some of the adjustments you noted but he was off with his kids.



  <= /p> 



Do you think if I plug th= e hole in the one baffle and close the gap in the top center with some rubb= er, will that make any difference?



  <= /p> 



Dan Schmitz



Tiger 4518B



KASH



  <= /p> 



  <= /p> 



From: owner-teamgr= umman-list-server(at)matronics.com (umman-list-server(at)matronics.com) [mailto:owner-teamgrumman-list-server(at)matronics.com=  ([email]owner-teamgrumman-list-server(at)matronics.com=%20[/email])] On Behalf Of Gary Vogt

Sent: Wednesday, May 23, 2012 1:50 PM

To: teamgrumman-li= st(at)matronics.com (st(at)matronics.com)

Subject: Re: Inlet Plugs for Jaguar Cowl on a Tige= r



 



Any updates on your= cowl . .  . speed?  CHTs?

 



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eamGrumman-List Email Forum -



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Discover

Joined: 26 Feb 2007
Posts: 429

Posted: Thu May 24, 2012 9:02 pm Post subject: Inlet Plugs for Jaguar Cowl on a Tiger

Gary, 

No

What do you mean, modified?





On May 24, 2012, at 12:35 PM, Gary Vogt <teamgrumman(at)yahoo.com (teamgrumman(at)yahoo.com)> wrote:



[quote]Ned, did you get the cowling modified?

        From: 923TE <923te(at)att.net (923te(at)att.net)>

 To: "teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)" <teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)> 

 Sent: Thursday, May 24, 2012 7:00 AM

 Subject: Re: Inlet Plugs for Jaguar Cowl on a Tiger

  

 

Dan,

I would think that flight testing and comparing at lower  altitudes, near sea level if possible, would maximize any effects due to drag reduction. Also, it is very difficult to get repeatable results. If you are not setting the engine the same you probably won't get repeatable results. Breaking in a cylinder definitely has a negative effect. But if your oil consumption has dropped since the new install it's probably already broke in. Lycoming says keep doing break in procedure for 50 hrs.

 I always set for best power by the Lycoming book method and then check it by adjusting the mixture with the prop set in manual mode to ensure maximum rpm. I fly at equivalent density altitude calculated on the fly by the Garmin 430 and also do the compass ordinates and formulas for wind correction. I try and fly at the same OAT. Seems to make a difference even though I am flying at equivalent DAs. I always have the same amount of fuel on board, have a freshly cleaned and waxed plane and prop and  ensure the same CG. The flaps have to be in exactly the same position, whatever that was last time. A difference of even 1 deg up or down will effect your speed. This is hard to get consistent. If a trim tab was touched between tests it will also affect your results. I always repeat the test 3 or 4 times until the numbers repeat. If they don't repeat then something is changing and I quit and try another day. It's really tedious to get good numbers but it's another excuse to go fly;) Food for thought, the air speed needle is about 2 kts wide, so it's really hard to detect a 1-2 knot speed increase. Thats one reason why I record indicated airspeed, true air speed and ground speed from the gps on every flight test. The last 2 are digital from the Garmin. Another uncanny result I continue to experience is that flying directly with the wind almost always gets me 2 more knots than flying directly into  the wind. I think David Fletcher told me this was his experience also. That's not supposed to be that way. Weird huh?

Something to think about is that if you are getting about the same speed as before Jaguar but have lower CHTs then you are in effect going faster. That energy is just being lost by the increased cooling drag. Maybe an area worth experimenting with;)

My after Jag experience is that the speed is about the same but the cooling is better by about 45 deg F. My plane was already fast so the typical speed increase from the Jag wouldn't be as likely for it. If I can get my CHTs back to 380s from the now 330s by cooling drag reduction, I think I might see that 5-7 kts increase I had hoped for.

BTW, what brand gauges are you using for the  temperatures?

Regards,

Ned



On May 24, 2012, at 7:04 AM, Dan Schmitz <Dan.Schmitz(at)calix.com (Dan.Schmitz(at)calix.com)> wrote:

 	  Quote: 	
		            If IAS is meaningless, then computing TAS off of IAS is a pointless exercise.  I was comparing IAS of density altitude to IAS of the same density altitude.   The TAS calculations will work out to be the same in either case.  Note that I completely ignored the IAS in a number of test runs where I simply used GPS ground speed in 3 directions to compute a TAS using some fun formulas.  The numbers all come out to â€œno  real changeâ€.

    

  Now, by the argument that a prop turning X RPM at Y density altitude will see no speed change even as there are drag reductionsâ€¦um counter-intuitive, but my  high altitude tests up to 13,300â€™ with new cowl so far show no changes either.  Of course, the problem with my high density altitude tests then are they are at â€œfullâ€ engine power, I lean for highest RPM in a speed test at higher altitudes.  I donâ€™t imagine  my engine is doing its best with a cylinder being broken in (maybe) and running on mineral oil.  So thereâ€™s power Iâ€™m not getting yet.  Do most Grummans see a 5 knot speedup after breaking in and switching to normal oil?  

    

  Dan Schmitz

  Tiger 4518B

  KASH

    

     From: owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com) [mailto:owner-teamgrumman-list-server(at)matronics.com] On Behalf Of Gary Vogt

 Sent: Thursday, May 24, 2012 12:37 AM

 To: teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)

 Subject: Re: Inlet Plugs for Jaguar Cowl on a Tiger

  

 

   

    Dan, I really can't tell from here what is with your plane.  I've installed 7 Jaguar Cowlings and not one was slower.  Do you know how to compute True Airspeed?   Indicated airspeed is meaningless.

  

    

  

       

 From: Dan Schmitz <Dan.Schmitz(at)calix.com (Dan.Schmitz(at)calix.com)>

 To: "teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)" <teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)> 

 Sent: Wednesday, May 23, 2012 11:55 AM

 Subject: RE: Inlet Plugs for Jaguar Cowl on a Tiger

  

   

      Just this morning, I computed the density altitudes for a test run last Saturday.  It was a perfect calm day for speed testing with light winds coming off the ocean (no  mountain waves).  But then I forgot most of my past results are on a my airplaneâ€™s pocket PC back home.  I donâ€™t think my new numbers are much different maybe one or two knots better.  I dropped in on Brooks with the hopes of talking to him about making some  of the adjustments you noted but he was off with his kids.

  

   

  

  Do you think if I plug the hole in the one baffle and close the gap in the top center with some rubber, will that make any difference?

  

   

  

  Dan Schmitz

  

  Tiger 4518B

  

  KASH

  

   

  

   

  

     From: owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com) [mailto:owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com)] On Behalf Of Gary Vogt

 Sent: Wednesday, May 23, 2012 1:50 PM

 To: teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)

 Subject: Re: Inlet Plugs for Jaguar Cowl on a Tiger

  

 

 

   

  

    Any updates on your cowl . .  . speed?  CHTs?

  

 

    

  

 

 

 

 

  	  Quote: 	
		      	
  ===============================  bsp;        - The TeamGrumman-List Email Forum -   Matronics List Features Navigator to browse  y List utilities such as List Un/Subscription,   Search & Download, 7-Day Browse, Chat, FAQ,  are, and much much more:  :p> bsp; --> http://www.matronics.com/Navigator?TeamGrumman-List  :p> ===============================  bsp;             - MATRONICS WEB FORUMS -  eat content also available via the Web Forums!  :p> bsp; --> http://forums.matronics.com  :p> ======  bsp;           - List Contribution Web Site -  hank you for your generous support!  bsp;                            -Matt Dralle, List Admin.  bsp; --> http://www.matronics.com/contribution  ===============================   	  Quote: 	
		    	
  

 

 

 

 

 

 

    kyï¿½ï¿½ï¿½"ï¿½íœ¢Z+ï¿½M4ï¿½Gï¿½qï¿½(ï¿½ï¿½ï¿½ï¿½wï¿½rï¿½ï¿½ï¿½ï¿½Ó…ï¿½ï¿½jaï¿½ï¿½iï¿½ï¿½ï¿½ï¿½ï¿½Iï¿½ï¿½Qhï¿½é”±ï¿½axÆï¿½ï¿½ï¿½rï¿½ï¿½ï¿½^jÛ«zï¿½Zï¿½(ï¿½ï¿½ï¿½ï¿½ï¿½Çï¿½éšŸ"ï¿½Ûï¿½Xï¿½ï¿½ï¿½,ï¿½ï¿½Zï¿½ï¿½ï¿½ï¿½Iï¿½Jï¿½ï¿½rï¿½ï¿½ï¿½*'ï¿½!ï¿½ï¿½yï¿½Ü„:0ï¿½Zwï¿½ï¿½ï¿½ï¿½ï¿½Ç‚ï¿½ï¿½Eï¿½ï¿½,ï¿½ï¿½ï¿½jwfï¿½ï¿½fï¿½ï¿½fï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½iï¿½ï¿½0ï¿½fï¿½ï¿½ï¿½ï¿½rï¿½(ï¿½ï¿½Zï¿½(ï¿½ï¿½ï¿½yï¿½ï¿½ï¿½ï¿½jrï¿½ï¿½mï¿½ï¿½ï¿½ï¿½&jï¿½ï¿½',rï¿½ï¿½5ï¿½â«hï¿½7ï¿½ï¿½jï¿½fï¿½.+-ï¿½Mï¿½ $ï¿½NECIï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½'ï¿½ï¿½ï¿½j[(jï¿½ï¿½zï¿½ï¿½yï¿½hï¿½ï¿½jï¿½~mï¿½ï¿½ß¢ï¿½ï¿½ï¿½fï¿½ï¿½ï¿½ï¿½rï¿½(ï¿½mï¿½ï¿½ß¢ï¿½ï¿½ï¿½fï¿½ï¿½ï¿½ï¿½rï¿½(ï¿½ï¿½ï¿½Bï¿½{kï¿½ï¿½ï¿½ï¿½ï¿½ï¿½yï¿½ï¿½ï¿½ï¿½ï¿½jy2ï¿½ï¿½ï¿½*.ï¿½ï¿½zï¿½.ï¿½Ë©ï¿½ï¿½ï¿½1ï¿½mï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½)Ú†ï¿½ï¿½ï¿½ï¿½iï¿½ï¿½0ï¿½fï¿½ï¿½ï¿½ï¿½rï¿½(ï¿½ï¿½(ï¿½ï¿½ï¿½nï¿½bï¿½xmï¿½ï¿½ï¿½ï¿½&jï¿½ï¿½',rï¿½ï¿½rï¿½ï¿½&ï¿½*'ï¿½ï¿½ï¿½ï¿½'ï¿½ï¿½k{ï¿½ï¿½w/ï¿½i

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[b]

Discover

Joined: 26 Feb 2007
Posts: 429

Posted: Thu May 24, 2012 9:05 pm Post subject: Inlet Plugs for Jaguar Cowl on a Tiger

Dan,

If you only get 138 ktas then you have something else draggen your plane

I suspect that something else isn't overcome by the drag reduction of the Jag cowl

If you were closer to Gary, he could find it.

You should at least be in the high 140's

Ned

On May 24, 2012, at 2:42 PM, Dan Schmitz <Dan.Schmitz(at)calix.com (Dan.Schmitz(at)calix.com)> wrote:



[quote]    v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} <![endif]-->  <![endif]-->   <![endif]-->    

All that work might be worth it to find out Iâ€™m going +/- 2 knots for real.  5 knots should be hard to miss, even if Iâ€™m being kinda sloppy.  I do most speed  tests solo starting with full tanks.  My usual concern is up/down drafts.  For â€œsome period of timeâ€ generally a few minutes, I have to be able to fly hands off at a stable speed and no altitude changes.  If Iâ€™m doing a GPS test, I do sometimes have to bump  the ailerons to keep an exact track.  My aileron trim isnâ€™t that perfect.  If I detect any up/down drafts any time during the flight, I discard the entire days numbers. 

  

All my temperature gauges, including OAT, are Electronics International. 

  

Dan 

  

    

 I always set for best power by the Lycoming book method and then check it by adjusting the mixture with the prop set in manual mode to ensure maximum rpm. I fly at equivalent density altitude calculated on the fly by the Garmin 430 and  also do the compass ordinates and formulas for wind correction. I try and fly at the same OAT. Seems to make a difference even though I am flying at equivalent DAs. I always have the same amount of fuel on board, have a freshly cleaned and waxed plane and  prop and ensure the same CG. The flaps have to be in exactly the same position, whatever that was last time. A difference of even 1 deg up or down will effect your speed. This is hard to get consistent. If a trim tab was touched between tests it will also  affect your results. I always repeat the test 3 or 4 times until the numbers repeat. If they don't repeat then something is changing and I quit and try another day. It's really tedious to get good numbers but it's another excuse to go fly;) Food for thought,  the air speed needle is about 2 kts wide, so it's really hard to detect a 1-2 knot speed increase. Thats one reason why I record indicated airspeed, true air speed and ground speed from the gps on every flight test. The last 2 are digital from the Garmin. Another  uncanny result I continue to experience is that flying directly with the wind almost always gets me 2 more knots than flying directly into the wind. I think David Fletcher told me this was his experience also. That's not supposed to be that way. Weird huh? 

  

  

  

Something to think about is that if you are getting about the same speed as before Jaguar but have lower CHTs then you are in effect going faster. That energy is just being lost by the increased cooling drag. Maybe an area worth experimenting  with;) 

  

  

  

My after Jag experience is that the speed is about the same but the cooling is better by about 45 deg F. My plane was already fast so the typical speed increase from the Jag wouldn't be as likely for it. If  I can get my CHTs back to 380s from the now 330s by cooling drag reduction, I think I might see that 5-7 kts increase I had hoped for. 

  

BTW, what brand gauges are you using for the temperatures? 

  

Regards, 

  

Ned 

  

  

  

On May 24, 2012, at 7:04 AM, Dan Schmitz <Dan.Schmitz(at)calix.com (Dan.Schmitz(at)calix.com)> wrote: 

  	  Quote: 	
		    

If IAS is meaningless, then computing TAS off of IAS is a pointless exercise.  I was comparing IAS of density altitude to IAS of the same density altitude.   The TAS calculations will work out to be the same in either case.  Note that I completely ignored the IAS in a number of test runs where I simply used GPS ground speed in 3 directions to compute a TAS using some fun formulas.  The numbers all come out to â€œno  real changeâ€. 

  

Now, by the argument that a prop turning X RPM at Y density altitude will see no speed change even as there are drag reductionsâ€¦um counter-intuitive, but my  high altitude tests up to 13,300â€™ with new cowl so far show no changes either.  Of course, the problem with my high density altitude tests then are they are at â€œfullâ€ engine power, I lean for highest RPM in a speed test at higher altitudes.  I donâ€™t imagine  my engine is doing its best with a cylinder being broken in (maybe) and running on mineral oil.  So thereâ€™s power Iâ€™m not getting yet.  Do most Grummans see a 5 knot speedup after breaking in and switching to normal oil?   

  

Dan Schmitz 

Tiger 4518B 

KASH 

     

From: owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com) [mailto:owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com)] On Behalf Of Gary Vogt

 Sent: Thursday, May 24, 2012 12:37 AM

 To: teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)

 Subject: Re: Inlet Plugs for Jaguar Cowl on a Tiger 

 

 

    

Dan, I really can't tell from here what is with your plane.  I've installed 7 Jaguar Cowlings and not one was slower.  Do you know how to compute True Airspeed?   Indicated airspeed is meaningless. 

  

  

       

 

From: Dan Schmitz <Dan.Schmitz(at)calix.com (Dan.Schmitz(at)calix.com)>

 To: "teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)" <teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)> 

 Sent: Wednesday, May 23, 2012 11:55 AM

 Subject: RE: Inlet Plugs for Jaguar Cowl on a Tiger 

 

      

Just this morning, I computed the density altitudes for a test run last Saturday.  It was a perfect calm day for speed testing with light winds coming off the ocean (no  mountain waves).  But then I forgot most of my past results are on a my airplaneâ€™s pocket PC back home.  I donâ€™t think my new numbers are much different maybe one or two knots better.  I dropped in on Brooks with the hopes of talking to him about making some  of the adjustments you noted but he was off with his kids. 

  

  

  

Do you think if I plug the hole in the one baffle and close the gap in the top center with some rubber, will that make any difference? 

  

  

  

Dan Schmitz 

  

Tiger 4518B 

  

KASH 

  

  

  

  

     

From: owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com) [mailto:owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com)] On Behalf Of Gary Vogt

 Sent: Wednesday, May 23, 2012 1:50 PM

 To: teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)

 Subject: Re: Inlet Plugs for Jaguar Cowl on a Tiger 

 

 

  

  

    

Any updates on your cowl . .  . speed?  CHTs? 

 

   

  

 

 

 

 

  	  Quote: 	
		   	
 

 

 

 

 

 

 

 	
 

 

    kyï¿½ï¿½ï¿½"ï¿½íœ¢Z+ï¿½M4ï¿½Gï¿½qï¿½(ï¿½ï¿½ï¿½ï¿½wï¿½rï¿½ï¿½ï¿½ï¿½Ó…ï¿½ï¿½jaï¿½ï¿½iï¿½ï¿½ï¿½ï¿½ï¿½Iï¿½ï¿½Qhï¿½é”±ï¿½axÆï¿½ï¿½ï¿½rï¿½ï¿½ï¿½^jÛ«zï¿½Zï¿½(ï¿½ï¿½ï¿½ï¿½ï¿½Çï¿½éšŸ"ï¿½Ûï¿½Xï¿½ï¿½ï¿½,ï¿½ï¿½Zï¿½ï¿½ï¿½ï¿½Iï¿½Jï¿½ï¿½rï¿½ï¿½ï¿½*'ï¿½!ï¿½ï¿½yï¿½Ü„:0ï¿½Zwï¿½ï¿½ï¿½ï¿½ï¿½Ç‚ï¿½ï¿½Eï¿½ï¿½,ï¿½ï¿½ï¿½jwfï¿½ï¿½fï¿½ï¿½fï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½iï¿½ï¿½0ï¿½fï¿½ï¿½ï¿½ï¿½rï¿½(ï¿½ï¿½Zï¿½(ï¿½ï¿½ï¿½yï¿½ï¿½ï¿½ï¿½jrï¿½ï¿½mï¿½ï¿½ï¿½ï¿½&jï¿½ï¿½',rï¿½ï¿½5ï¿½â«hï¿½7ï¿½ï¿½jï¿½fï¿½.+-ï¿½Mï¿½ $ï¿½NECIï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½'ï¿½ï¿½ï¿½j[(jï¿½ï¿½zï¿½ï¿½yï¿½hï¿½ï¿½jï¿½~mï¿½ï¿½ß¢ï¿½ï¿½ï¿½fï¿½ï¿½ï¿½ï¿½rï¿½(ï¿½mï¿½ï¿½ß¢ï¿½ï¿½ï¿½fï¿½ï¿½ï¿½ï¿½rï¿½(ï¿½ï¿½ï¿½Bï¿½{kï¿½ï¿½ï¿½ï¿½ï¿½ï¿½yï¿½ï¿½ï¿½ï¿½ï¿½jy2ï¿½ï¿½ï¿½*.ï¿½ï¿½zï¿½.ï¿½Ë©ï¿½ï¿½ï¿½1ï¿½mï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½)Ú†ï¿½ï¿½ï¿½ï¿½iï¿½ï¿½0ï¿½fï¿½ï¿½ï¿½ï¿½rï¿½(ï¿½ï¿½(ï¿½ï¿½ï¿½nï¿½bï¿½xmï¿½ï¿½ï¿½ï¿½&jï¿½ï¿½',rï¿½ï¿½rï¿½ï¿½&ï¿½*'ï¿½ï¿½ï¿½ï¿½'ï¿½ï¿½k{ï¿½ï¿½w/ï¿½i

[b]

teamgrumman(at)yahoo.com
Guest

Posted: Thu May 24, 2012 9:46 pm Post subject: Inlet Plugs for Jaguar Cowl on a Tiger

N3752W: 144 knots

N1976T: 145 knots

N28747: 148 knots



If your plane is not 140 knots, something is wrong. What prop are you turning?



Gary

Sent from my iPad



On May 24, 2012, at 1:10 PM, Dan Schmitz <Dan.Schmitz(at)calix.com> wrote:



[quote] Me too (wish I was closer).  Iâ€™ll be at Oshkosh for the AYA convention.  Anyway what kind of speeds were you getting pre and post Jaguar?  My best speeds both pre and post are 138 knots.  Did your other planes go from 133 to 138?  Iâ€™ve always been able to run a bit over 2700 RPM at 8000â€™ and thatâ€™s with a 64â€ pitch sensenich.  Right about 9000â€™ DA is where full throttle equals 2700 RPM (strobe checked, not tach), again both before and after the new cowl.

  

 Dan

  

 From: owner-teamgrumman-list-server(at)matronics.com [mailto:owner-teamgrumman-list-server(at)matronics.com] On Behalf Of Gary Vogt

 Sent: Thursday, May 24, 2012 1:29 PM

 To: teamgrumman-list(at)matronics.com

 Subject: Re: Inlet Plugs for Jaguar Cowl on a Tiger

  

 Well, Dan,

  

 On N3752W, the only change to the plane was the cowling.  Right out of the hangar it was 5 knots (TAS) faster than the stock cowling at altitudes between 1500 feet and 5500 feet and 2700 rpm.  It was also easier to run past 2700 rpm at 8000 feet.  So, I don't know what to tell you.  

  

 When I installed the very first one on N119ST, it was 9 knots (TAS) faster.  On my plane with a 65-63-61 prop, it was 10 knots (TAS) faster.  Both at 2700 rpm.  My old cowling, however, didn't fit well, was debonding and patched all over.  

  

 I wish you were closer.  

  

 Gary

  

 From: Dan Schmitz <Dan.Schmitz(at)calix.com>

 To: "teamgrumman-list(at)matronics.com" <teamgrumman-list(at)matronics.com> 

 Sent: Thursday, May 24, 2012 5:04 AM

 Subject: RE: Inlet Plugs for Jaguar Cowl on a Tiger

  

 If IAS is meaningless, then computing TAS off of IAS is a pointless exercise.  I was comparing IAS of density altitude to IAS of the same density altitude.  The TAS calculations will work out to be the same in either case.  Note that I completely ignored the IAS in a number of test runs where I simply used GPS ground speed in 3 directions to compute a TAS using some fun formulas.  The numbers all come out to Ã¢â‚¬Å“no real changeÃ¢â‚¬ï¿½.

  

 Now, by the argument that a prop turning X RPM at Y density altitude will see no speed change even as there are drag reductionsÃ¢â‚¬Â¦um counter-intuitive, but my high altitude tests up to 13,300Ã¢â‚¬â„¢ with new cowl so far show no changes either.  Of course, the problem with my high density altitude tests then are they are at Ã¢â‚¬Å“fullÃ¢â‚¬ï¿½ engine power, I lean for highest RPM in a speed test at higher altitudes.  I donÃ¢â‚¬â„¢t imagine my engine is doing its best with a cylinder being broken in (maybe) and running on mineral oil.  So thereÃ¢â‚¬â„¢s power IÃ¢â‚¬â„¢m not getting yet.  Do most Grummans see a 5 knot speedup after breaking in and switching to normal oil? 

  

 Dan Schmitz

 Tiger 4518B

 KASH

  

 From: owner-teamgrumman-list-server(at)matronics.com [mailto:owner-teamgrumman-list-server(at)matronics.com] On Behalf Of Gary Vogt

 Sent: Thursday, May 24, 2012 12:37 AM

 To: teamgrumman-list(at)matronics.com

 Subject: Re: Inlet Plugs for Jaguar Cowl on a Tiger

  

 Dan, I really can't tell from here what is with your plane.  I've installed 7 Jaguar Cowlings and not one was slower.  Do you know how to compute True Airspeed?  Indicated airspeed is meaningless.

  

 From: Dan Schmitz <Dan.Schmitz(at)calix.com>

 To: "teamgrumman-list(at)matronics.com" <teamgrumman-list(at)matronics.com> 

 Sent: Wednesday, May 23, 2012 11:55 AM

 Subject: RE: Inlet Plugs for Jaguar Cowl on a Tiger

  

 Just this morning, I computed the density altitudes for a test run last Saturday.  It was a perfect calm day for speed testing with light winds coming off the ocean (no mountain waves).  But then I forgot most of my past results are on a my airplaneÃ¢â‚¬â„¢s pocket PC back home.  I donÃ¢â‚¬â„¢t think my new numbers are much different maybe one or two knots better.  I dropped in on Brooks with the hopes of talking to him about making some of the adjustments you noted but he was off with his kids

teamgrumman(at)yahoo.com
Guest

Posted: Thu May 24, 2012 9:49 pm Post subject: Inlet Plugs for Jaguar Cowl on a Tiger

Oh, I see what prop now. 



I've never flown a Tiger that didn't do at least 138 knots true. 



Brian, what are your speeds?



Gary

Sent from my iPad



On May 24, 2012, at 1:10 PM, Dan Schmitz <Dan.Schmitz(at)calix.com> wrote:



[quote] Me too (wish I was closer).  Iâ€™ll be at Oshkosh for the AYA convention.  Anyway what kind of speeds were you getting pre and post Jaguar?  My best speeds both pre and post are 138 knots.  Did your other planes go from 133 to 138?  Iâ€™ve always been able to run a bit over 2700 RPM at 8000â€™ and thatâ€™s with a 64â€ pitch sensenich.  Right about 9000â€™ DA is where full throttle equals 2700 RPM (strobe checked, not tach), again both before and after the new cowl.

  

 Dan

  

 From: owner-teamgrumman-list-server(at)matronics.com [mailto:owner-teamgrumman-list-server(at)matronics.com] On Behalf Of Gary Vogt

 Sent: Thursday, May 24, 2012 1:29 PM

 To: teamgrumman-list(at)matronics.com

 Subject: Re: Inlet Plugs for Jaguar Cowl on a Tiger

  

 Well, Dan,

  

 On N3752W, the only change to the plane was the cowling.  Right out of the hangar it was 5 knots (TAS) faster than the stock cowling at altitudes between 1500 feet and 5500 feet and 2700 rpm.  It was also easier to run past 2700 rpm at 8000 feet.  So, I don't know what to tell you.  

  

 When I installed the very first one on N119ST, it was 9 knots (TAS) faster.  On my plane with a 65-63-61 prop, it was 10 knots (TAS) faster.  Both at 2700 rpm.  My old cowling, however, didn't fit well, was debonding and patched all over.  

  

 I wish you were closer.  

  

 Gary

  

 From: Dan Schmitz <Dan.Schmitz(at)calix.com>

 To: "teamgrumman-list(at)matronics.com" <teamgrumman-list(at)matronics.com> 

 Sent: Thursday, May 24, 2012 5:04 AM

 Subject: RE: Inlet Plugs for Jaguar Cowl on a Tiger

  

 If IAS is meaningless, then computing TAS off of IAS is a pointless exercise.  I was comparing IAS of density altitude to IAS of the same density altitude.  The TAS calculations will work out to be the same in either case.  Note that I completely ignored the IAS in a number of test runs where I simply used GPS ground speed in 3 directions to compute a TAS using some fun formulas.  The numbers all come out to Ã¢â‚¬Å“no real changeÃ¢â‚¬ï¿½.

  

 Now, by the argument that a prop turning X RPM at Y density altitude will see no speed change even as there are drag reductionsÃ¢â‚¬Â¦um counter-intuitive, but my high altitude tests up to 13,300Ã¢â‚¬â„¢ with new cowl so far show no changes either.  Of course, the problem with my high density altitude tests then are they are at Ã¢â‚¬Å“fullÃ¢â‚¬ï¿½ engine power, I lean for highest RPM in a speed test at higher altitudes.  I donÃ¢â‚¬â„¢t imagine my engine is doing its best with a cylinder being broken in (maybe) and running on mineral oil.  So thereÃ¢â‚¬â„¢s power IÃ¢â‚¬â„¢m not getting yet.  Do most Grummans see a 5 knot speedup after breaking in and switching to normal oil? 

  

 Dan Schmitz

 Tiger 4518B

 KASH

  

 From: owner-teamgrumman-list-server(at)matronics.com [mailto:owner-teamgrumman-list-server(at)matronics.com] On Behalf Of Gary Vogt

 Sent: Thursday, May 24, 2012 12:37 AM

 To: teamgrumman-list(at)matronics.com

 Subject: Re: Inlet Plugs for Jaguar Cowl on a Tiger

  

 Dan, I really can't tell from here what is with your plane.  I've installed 7 Jaguar Cowlings and not one was slower.  Do you know how to compute True Airspeed?  Indicated airspeed is meaningless.

  

 From: Dan Schmitz <Dan.Schmitz(at)calix.com>

 To: "teamgrumman-list(at)matronics.com" <teamgrumman-list(at)matronics.com> 

 Sent: Wednesday, May 23, 2012 11:55 AM

 Subject: RE: Inlet Plugs for Jaguar Cowl on a Tiger

  

 Just this morning, I computed the density altitudes for a test run last Saturday.  It was a perfect calm day for speed testing with light winds coming off the ocean (no mountain waves).  But then I forgot most of my past results are on a my airplaneÃ¢â‚¬â„¢s pocket PC back home.  I donÃ¢â‚¬â„¢t think my new numbers are much different maybe one or two knots better.  I dropped in on Brooks with the hopes of talking to him about making some of the adjustments you noted but he was off with his kids

teamgrumman(at)yahoo.com
Guest

Posted: Thu May 24, 2012 9:55 pm Post subject: Inlet Plugs for Jaguar Cowl on a Tiger

Changing the angle of the cowling. 



Gary

Sent from my iPad



On May 24, 2012, at 10:01 PM, 923TE <923te(at)att.net (923te(at)att.net)> wrote:



[quote]Gary, 

No

What do you mean, modified?





On May 24, 2012, at 12:35 PM, Gary Vogt <teamgrumman(at)yahoo.com (teamgrumman(at)yahoo.com)> wrote:



 	  Quote: 	
		  Ned, did you get the cowling modified?

        From: 923TE <923te(at)att.net (923te(at)att.net)>

 To: "teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)" <teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)> 

 Sent: Thursday, May 24, 2012 7:00 AM

 Subject: Re: Inlet Plugs for Jaguar Cowl on a Tiger

  

 

Dan,

I would think that flight testing and comparing at lower  altitudes, near sea level if possible, would maximize any effects due to drag reduction. Also, it is very difficult to get repeatable results. If you are not setting the engine the same you probably won't get repeatable results. Breaking in a cylinder definitely has a negative effect. But if your oil consumption has dropped since the new install it's probably already broke in. Lycoming says keep doing break in procedure for 50 hrs.

 I always set for best power by the Lycoming book method and then check it by adjusting the mixture with the prop set in manual mode to ensure maximum rpm. I fly at equivalent density altitude calculated on the fly by the Garmin 430 and also do the compass ordinates and formulas for wind correction. I try and fly at the same OAT. Seems to make a difference even though I am flying at equivalent DAs. I always have the same amount of fuel on board, have a freshly cleaned and waxed plane and prop and  ensure the same CG. The flaps have to be in exactly the same position, whatever that was last time. A difference of even 1 deg up or down will effect your speed. This is hard to get consistent. If a trim tab was touched between tests it will also affect your results. I always repeat the test 3 or 4 times until the numbers repeat. If they don't repeat then something is changing and I quit and try another day. It's really tedious to get good numbers but it's another excuse to go fly;) Food for thought, the air speed needle is about 2 kts wide, so it's really hard to detect a 1-2 knot speed increase. Thats one reason why I record indicated airspeed, true air speed and ground speed from the gps on every flight test. The last 2 are digital from the Garmin. Another uncanny result I continue to experience is that flying directly with the wind almost always gets me 2 more knots than flying directly into  the wind. I think David Fletcher told me this was his experience also. That's not supposed to be that way. Weird huh?

Something to think about is that if you are getting about the same speed as before Jaguar but have lower CHTs then you are in effect going faster. That energy is just being lost by the increased cooling drag. Maybe an area worth experimenting with;)

My after Jag experience is that the speed is about the same but the cooling is better by about 45 deg F. My plane was already fast so the typical speed increase from the Jag wouldn't be as likely for it. If I can get my CHTs back to 380s from the now 330s by cooling drag reduction, I think I might see that 5-7 kts increase I had hoped for.

BTW, what brand gauges are you using for the  temperatures?

Regards,

Ned



On May 24, 2012, at 7:04 AM, Dan Schmitz <Dan.Schmitz(at)calix.com (Dan.Schmitz(at)calix.com)> wrote:

 	  Quote: 	
		            If IAS is meaningless, then computing TAS off of IAS is a pointless exercise.  I was comparing IAS of density altitude to IAS of the same density altitude.   The TAS calculations will work out to be the same in either case.  Note that I completely ignored the IAS in a number of test runs where I simply used GPS ground speed in 3 directions to compute a TAS using some fun formulas.  The numbers all come out to â€œno  real changeâ€.

    

  Now, by the argument that a prop turning X RPM at Y density altitude will see no speed change even as there are drag reductionsâ€¦um counter-intuitive, but my  high altitude tests up to 13,300â€™ with new cowl so far show no changes either.  Of course, the problem with my high density altitude tests then are they are at â€œfullâ€ engine power, I lean for highest RPM in a speed test at higher altitudes.  I donâ€™t imagine  my engine is doing its best with a cylinder being broken in (maybe) and running on mineral oil.  So thereâ€™s power Iâ€™m not getting yet.  Do most Grummans see a 5 knot speedup after breaking in and switching to normal oil?  

    

  Dan Schmitz

  Tiger 4518B

  KASH

    

     From: owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com) [mailto:owner-teamgrumman-list-server(at)matronics.com] On Behalf Of Gary Vogt

 Sent: Thursday, May 24, 2012 12:37 AM

 To: teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)

 Subject: Re: Inlet Plugs for Jaguar Cowl on a Tiger

  

 

   

    Dan, I really can't tell from here what is with your plane.  I've installed 7 Jaguar Cowlings and not one was slower.  Do you know how to compute True Airspeed?   Indicated airspeed is meaningless.

  

    

  

       

 From: Dan Schmitz <Dan.Schmitz(at)calix.com (Dan.Schmitz(at)calix.com)>

 To: "teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)" <teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)> 

 Sent: Wednesday, May 23, 2012 11:55 AM

 Subject: RE: Inlet Plugs for Jaguar Cowl on a Tiger

  

   

      Just this morning, I computed the density altitudes for a test run last Saturday.  It was a perfect calm day for speed testing with light winds coming off the ocean (no  mountain waves).  But then I forgot most of my past results are on a my airplaneâ€™s pocket PC back home.  I donâ€™t think my new numbers are much different maybe one or two knots better.  I dropped in on Brooks with the hopes of talking to him about making some  of the adjustments you noted but he was off with his kids.

  

   

  

  Do you think if I plug the hole in the one baffle and close the gap in the top center with some rubber, will that make any difference?

  

   

  

  Dan Schmitz

  

  Tiger 4518B

  

  KASH

  

   

  

   

  

     From: owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com) [mailto:owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com)] On Behalf Of Gary Vogt

 Sent: Wednesday, May 23, 2012 1:50 PM

 To: teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)

 Subject: Re: Inlet Plugs for Jaguar Cowl on a Tiger

  

 

 

   

  

    Any updates on your cowl . .  . speed?  CHTs?

  

 

    

  

 

 

 

 

  	  Quote: 	
		      	
  ======  bsp;        - The TeamGrumman-List Email Forum -   Matronics List Features Navigator to browse  y List utilities such as List Un/Subscription,   Search & Download, 7-Day Browse, Chat, FAQ,  are, and much much more:  :p> bsp; --> http://www.matronics.com/Navigator?TeamGrumman-List  :p> ======  bsp;             - MATRONICS WEB FORUMS -  eat content also available via the Web Forums!  :p> bsp; --> http://forums.matronics.com  :p> ======  bsp;           - List Contribution Web Site -  hank you for your generous support!  bsp;                            -Matt Dralle, List Admin.  bsp; --> http://www.matronics.com/contribution  ======   	  Quote: 	
		    	
  

 

 

 

 

 

 

    kyï¿½ï¿½ï¿½"ï¿½íœ¢Z+ï¿½M4ï¿½Gï¿½qï¿½(ï¿½ï¿½ï¿½ï¿½wï¿½rï¿½ï¿½ï¿½ï¿½Ó…ï¿½ï¿½jaï¿½ï¿½iï¿½ï¿½ï¿½ï¿½ï¿½Iï¿½ï¿½Qhï¿½é”±ï¿½axÆï¿½ï¿½ï¿½rï¿½ï¿½ï¿½^jÛ«zï¿½Zï¿½(ï¿½ï¿½ï¿½ï¿½ï¿½Çï¿½éšŸ"ï¿½Ûï¿½Xï¿½ï¿½ï¿½,ï¿½ï¿½Zï¿½ï¿½ï¿½ï¿½Iï¿½Jï¿½ï¿½rï¿½ï¿½ï¿½*'ï¿½!ï¿½ï¿½yï¿½Ü„:0ï¿½Zwï¿½ï¿½ï¿½ï¿½ï¿½Ç‚ï¿½ï¿½Eï¿½ï¿½,ï¿½ï¿½ï¿½jwfï¿½ï¿½fï¿½ï¿½fï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½iï¿½ï¿½0ï¿½fï¿½ï¿½ï¿½ï¿½rï¿½(ï¿½ï¿½Zï¿½(ï¿½ï¿½ï¿½yï¿½ï¿½ï¿½ï¿½jrï¿½ï¿½mï¿½ï¿½ï¿½ï¿½&jï¿½ï¿½',rï¿½ï¿½5ï¿½â«hï¿½7ï¿½ï¿½jï¿½fï¿½.+-ï¿½Mï¿½ $ï¿½NECIï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½'ï¿½ï¿½ï¿½j[(jï¿½ï¿½zï¿½ï¿½yï¿½hï¿½ï¿½jï¿½~mï¿½ï¿½ß¢ï¿½ï¿½ï¿½fï¿½ï¿½ï¿½ï¿½rï¿½(ï¿½mï¿½ï¿½ß¢ï¿½ï¿½ï¿½fï¿½ï¿½ï¿½ï¿½rï¿½(ï¿½ï¿½ï¿½Bï¿½{kï¿½ï¿½ï¿½ï¿½ï¿½ï¿½yï¿½ï¿½ï¿½ï¿½ï¿½jy2ï¿½ï¿½ï¿½*.ï¿½ï¿½zï¿½.ï¿½Ë©ï¿½ï¿½ï¿½1ï¿½mï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½)Ú†ï¿½ï¿½ï¿½ï¿½iï¿½ï¿½0ï¿½fï¿½ï¿½ï¿½ï¿½rï¿½(ï¿½ï¿½(ï¿½ï¿½ï¿½nï¿½bï¿½xmï¿½ï¿½ï¿½ï¿½&jï¿½ï¿½',rï¿½ï¿½rï¿½ï¿½&ï¿½*'ï¿½ï¿½ï¿½ï¿½'ï¿½ï¿½k{ï¿½ï¿½w/ï¿½i

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[b]

Dan.Schmitz(at)calix.com
Guest

Posted: Fri May 25, 2012 3:57 am Post subject: Inlet Plugs for Jaguar Cowl on a Tiger

Is that full throttle at sea level?  I should say that my 138 knots was staying within the bounds of 75% power.  If I did full power at 1000â€™ I expect Iâ€™d be in the low 140s for sure.  Donâ€™t know how high.



Dan



From: owner-teamgrumman-list-server(at)matronics.com [mailto:owner-teamgrumman-list-server(at)matronics.com] On Behalf Of Gary L Vogt

Sent: Friday, May 25, 2012 1:46 AM

To: teamgrumman-list(at)matronics.com

Subject: Re: TeamGrumman-List: Inlet Plugs for Jaguar Cowl on a Tiger



N3752W: 144 knots

N1976T: 145 knots

N28747: 148 knots



If your plane is not 140 knots, something is wrong. What prop are you turning?

Gary

Sent from my iPad



On May 24, 2012, at 1:10 PM, Dan Schmitz <Dan.Schmitz(at)calix.com<mailto:Dan.Schmitz(at)calix.com>> wrote:

Me too (wish I was closer).  Iâ€™ll be at Oshkosh for the AYA convention.  Anyway what kind of speeds were you getting pre and post Jaguar?  My best speeds both pre and post are 138 knots.  Did your other planes go from 133 to 138?  Iâ€™ve always been able to run a bit over 2700 RPM at 8000â€™ and thatâ€™s with a 64â€ pitch sensenich.  Right about 9000â€™ DA is where full throttle equals 2700 RPM (strobe checked, not tach), again both before and after the new cowl.



Dan



From: owner-teamgrumman-list-server(at)matronics.com<mailto:owner-teamgrumman-list-server(at)matronics.com> [mailto:owner-teamgrumman-list-server(at)matronics.com] On Behalf Of Gary Vogt

Sent: Thursday, May 24, 2012 1:29 PM

To: teamgrumman-list(at)matronics.com<mailto:teamgrumman-list(at)matronics.com>

Subject: Re: TeamGrumman-List: Inlet Plugs for Jaguar Cowl on a Tiger



Well, Dan,



On N3752W, the only change to the plane was the cowling.  Right out of the hangar it was 5 knots (TAS) faster than the stock cowling at altitudes between 1500 feet and 5500 feet and 2700 rpm.  It was also easier to run past 2700 rpm at 8000 feet.  So, I don't know what to tell you.



When I installed the very first one on N119ST, it was 9 knots (TAS) faster.  On my plane with a 65-63-61 prop, it was 10 knots (TAS) faster.  Both at 2700 rpm.  My old cowling, however, didn't fit well, was debonding and patched all over.



I wish you were closer.



Gary



________________________________

From: Dan Schmitz <Dan.Schmitz(at)calix.com<mailto:Dan.Schmitz(at)calix.com>>

To: "teamgrumman-list(at)matronics.com<mailto:teamgrumman-list(at)matronics.com>" <teamgrumman-list(at)matronics.com<mailto:teamgrumman-list(at)matronics.com>>

Sent: Thursday, May 24, 2012 5:04 AM

Subject: RE: TeamGrumman-List: Inlet Plugs for Jaguar Cowl on a Tiger



If IAS is meaningless, then computing TAS off of IAS is a pointless exercise.  I was comparing IAS of density altitude to IAS of the same density altitude.  The TAS calculations will work out to be the same in either case.  Note that I completely ignored the IAS in a number of test runs where I simply used GPS ground speed in 3 directions to compute a TAS using some fun formulas.  The numbers all come out to Ã¢â‚¬Å“no real changeÃ¢â‚¬ï¿½.



Now, by the argument that a prop turning X RPM at Y density altitude will see no speed change even as there are drag reductionsÃ¢â‚¬Â¦um counter-intuitive, but my high altitude tests up to 13,300Ã¢â‚¬â„¢ with new cowl so far show no changes either.  Of course, the problem with my high density altitude tests then are they are at Ã¢â‚¬Å“fullÃ¢â‚¬ï¿½ engine power, I lean for highest RPM in a speed test at higher altitudes.  I donÃ¢â‚¬â„¢t imagine my engine is doing its best with a cylinder being broken in (maybe) and running on mineral oil.  So thereÃ¢â‚¬â„¢s power IÃ¢â‚¬â„¢m not getting yet.  Do most Grummans see a 5 knot speedup after breaking in and switching to normal oil?



Dan Schmitz

Tiger 4518B

KASH

Discover

Joined: 26 Feb 2007
Posts: 429

Posted: Fri May 25, 2012 4:35 am Post subject: Inlet Plugs for Jaguar Cowl on a Tiger

Then no I did not modify the cowling itself.  What I did was:

1) I tightened the top pilot side engine mount as it had no threads showing

2) this brought the spinner into alignment with the factory cowl

3) the Jaguar cowl was now too short when aligned with the spinner in its proper position

4) I lengthened the Jaguar cowl probably to the same length it was when it came out of the molds before it was trimmed

5) I performed the Jaguar cowl installation according to the installation instructions you provided. 

Ned



On May 25, 2012, at 12:54 AM, Gary L Vogt <teamgrumman(at)yahoo.com (teamgrumman(at)yahoo.com)> wrote:



[quote]Changing the angle of the cowling. 



Gary

Sent from my iPad



On May 24, 2012, at 10:01 PM, 923TE <923te(at)att.net (923te(at)att.net)> wrote:



 	  Quote: 	
		  Gary, 

No

What do you mean, modified?





On May 24, 2012, at 12:35 PM, Gary Vogt <teamgrumman(at)yahoo.com (teamgrumman(at)yahoo.com)> wrote:



 	  Quote: 	
		  Ned, did you get the cowling modified?

        From: 923TE <923te(at)att.net (923te(at)att.net)>

 To: "teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)" <teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)> 

 Sent: Thursday, May 24, 2012 7:00 AM

 Subject: Re: Inlet Plugs for Jaguar Cowl on a Tiger

  

 

Dan,

I would think that flight testing and comparing at lower  altitudes, near sea level if possible, would maximize any effects due to drag reduction. Also, it is very difficult to get repeatable results. If you are not setting the engine the same you probably won't get repeatable results. Breaking in a cylinder definitely has a negative effect. But if your oil consumption has dropped since the new install it's probably already broke in. Lycoming says keep doing break in procedure for 50 hrs.

 I always set for best power by the Lycoming book method and then check it by adjusting the mixture with the prop set in manual mode to ensure maximum rpm. I fly at equivalent density altitude calculated on the fly by the Garmin 430 and also do the compass ordinates and formulas for wind correction. I try and fly at the same OAT. Seems to make a difference even though I am flying at equivalent DAs. I always have the same amount of fuel on board, have a freshly cleaned and waxed plane and prop and  ensure the same CG. The flaps have to be in exactly the same position, whatever that was last time. A difference of even 1 deg up or down will effect your speed. This is hard to get consistent. If a trim tab was touched between tests it will also affect your results. I always repeat the test 3 or 4 times until the numbers repeat. If they don't repeat then something is changing and I quit and try another day. It's really tedious to get good numbers but it's another excuse to go fly;) Food for thought, the air speed needle is about 2 kts wide, so it's really hard to detect a 1-2 knot speed increase. Thats one reason why I record indicated airspeed, true air speed and ground speed from the gps on every flight test. The last 2 are digital from the Garmin. Another uncanny result I continue to experience is that flying directly with the wind almost always gets me 2 more knots than flying directly into  the wind. I think David Fletcher told me this was his experience also. That's not supposed to be that way. Weird huh?

Something to think about is that if you are getting about the same speed as before Jaguar but have lower CHTs then you are in effect going faster. That energy is just being lost by the increased cooling drag. Maybe an area worth experimenting with;)

My after Jag experience is that the speed is about the same but the cooling is better by about 45 deg F. My plane was already fast so the typical speed increase from the Jag wouldn't be as likely for it. If I can get my CHTs back to 380s from the now 330s by cooling drag reduction, I think I might see that 5-7 kts increase I had hoped for.

BTW, what brand gauges are you using for the  temperatures?

Regards,

Ned



On May 24, 2012, at 7:04 AM, Dan Schmitz <Dan.Schmitz(at)calix.com (Dan.Schmitz(at)calix.com)> wrote:

 	  Quote: 	
		            If IAS is meaningless, then computing TAS off of IAS is a pointless exercise.  I was comparing IAS of density altitude to IAS of the same density altitude.   The TAS calculations will work out to be the same in either case.  Note that I completely ignored the IAS in a number of test runs where I simply used GPS ground speed in 3 directions to compute a TAS using some fun formulas.  The numbers all come out to â€œno  real changeâ€.

    

  Now, by the argument that a prop turning X RPM at Y density altitude will see no speed change even as there are drag reductionsâ€¦um counter-intuitive, but my  high altitude tests up to 13,300â€™ with new cowl so far show no changes either.  Of course, the problem with my high density altitude tests then are they are at â€œfullâ€ engine power, I lean for highest RPM in a speed test at higher altitudes.  I donâ€™t imagine  my engine is doing its best with a cylinder being broken in (maybe) and running on mineral oil.  So thereâ€™s power Iâ€™m not getting yet.  Do most Grummans see a 5 knot speedup after breaking in and switching to normal oil?  

    

  Dan Schmitz

  Tiger 4518B

  KASH

    

     From: owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com) [mailto:owner-teamgrumman-list-server(at)matronics.com] On Behalf Of Gary Vogt

 Sent: Thursday, May 24, 2012 12:37 AM

 To: teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)

 Subject: Re: Inlet Plugs for Jaguar Cowl on a Tiger

  

 

   

    Dan, I really can't tell from here what is with your plane.  I've installed 7 Jaguar Cowlings and not one was slower.  Do you know how to compute True Airspeed?   Indicated airspeed is meaningless.

  

    

  

       

 From: Dan Schmitz <Dan.Schmitz(at)calix.com (Dan.Schmitz(at)calix.com)>

 To: "teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)" <teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)> 

 Sent: Wednesday, May 23, 2012 11:55 AM

 Subject: RE: Inlet Plugs for Jaguar Cowl on a Tiger

  

   

      Just this morning, I computed the density altitudes for a test run last Saturday.  It was a perfect calm day for speed testing with light winds coming off the ocean (no  mountain waves).  But then I forgot most of my past results are on a my airplaneâ€™s pocket PC back home.  I donâ€™t think my new numbers are much different maybe one or two knots better.  I dropped in on Brooks with the hopes of talking to him about making some  of the adjustments you noted but he was off with his kids.

  

   

  

  Do you think if I plug the hole in the one baffle and close the gap in the top center with some rubber, will that make any difference?

  

   

  

  Dan Schmitz

  

  Tiger 4518B

  

  KASH

  

   

  

   

  

     From: owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com) [mailto:owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com)] On Behalf Of Gary Vogt

 Sent: Wednesday, May 23, 2012 1:50 PM

 To: teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)

 Subject: Re: Inlet Plugs for Jaguar Cowl on a Tiger

  

 

 

   

  

    Any updates on your cowl . .  . speed?  CHTs?

  

 

    

  

 

 

 

 

  	  Quote: 	
		      	
  ======  bsp;        - The TeamGrumman-List Email Forum -   Matronics List Features Navigator to browse  y List utilities such as List Un/Subscription,   Search & Download, 7-Day Browse, Chat, FAQ,  are, and much much more:  :p> bsp; --> http://www.matronics.com/Navigator?TeamGrumman-List  :p> ======  bsp;             - MATRONICS WEB FORUMS -  eat content also available via the Web Forums!  :p> bsp; --> http://forums.matronics.com  :p> ======  bsp;           - List Contribution Web Site -  hank you for your generous support!  bsp;                            -Matt Dralle, List Admin.  bsp; --> http://www.matronics.com/contribution  ======   	  Quote: 	
		    	
  

 

 

 

 

 

 

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[b]

Discover

Joined: 26 Feb 2007
Posts: 429

Posted: Fri May 25, 2012 4:45 am Post subject: Inlet Plugs for Jaguar Cowl on a Tiger

Dan the only way to get good results is at wide open throttle. You have no way of positively identifying when you are at 75% power in any consistent way. So if your "flight testing" was not done at wide open throttle and at the same best power setting then your data has no use in a pre - post Jaguar speed comparison. Calculated results just don't cut it.

When I change direction I fly for a minimum of 10 minutes on that new heading before I am confident that I am seeing a stabilized air speed. Flight testing is not really that easy to perform.

On May 25, 2012, at 6:52 AM, Dan Schmitz <Dan.Schmitz(at)calix.com (Dan.Schmitz(at)calix.com)> wrote:



[quote]    v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} <![endif]-->  <![endif]-->   <![endif]-->    

Is that full throttle at sea level?  I should say that my 138 knots was staying within the bounds of 75% power.  If I did full power at 1000â€™ I expect Iâ€™d be  in the low 140s for sure.  Donâ€™t know how high. 

  

Dan 

     

From: owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com) [mailto:owner-teamgrumman-list-server(at)matronics.com] On Behalf Of Gary L Vogt

 Sent: Friday, May 25, 2012 1:46 AM

 To: teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)

 Subject: Re: Inlet Plugs for Jaguar Cowl on a Tiger 

 

 

   

N3752W: 144 knots 

  

N1976T: 145 knots 

  

N28747: 148 knots 

  

  

  

If your plane is not 140 knots, something is wrong. What prop are you turning?  

Gary 

 

Sent from my iPad 

  



 On May 24, 2012, at 1:10 PM, Dan Schmitz <Dan.Schmitz(at)calix.com (Dan.Schmitz(at)calix.com)> wrote: 

  	  Quote: 	
		    

Me too (wish I was closer).  Iâ€™ll be at Oshkosh for the AYA convention.  Anyway what kind of speeds were you getting pre and post Jaguar?  My best speeds both  pre and post are 138 knots.  Did your other planes go from 133 to 138?  Iâ€™ve always been able to run a bit over 2700 RPM at 8000â€™ and thatâ€™s with a 64â€ pitch sensenich.  Right about 9000â€™ DA is where full throttle equals 2700 RPM (strobe checked, not tach),  again both before and after the new cowl. 

  

Dan 

     

From: owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com) [mailto:owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com)] On Behalf Of Gary Vogt

 Sent: Thursday, May 24, 2012 1:29 PM

 To: teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)

 Subject: Re: Inlet Plugs for Jaguar Cowl on a Tiger 

 

 

    

Well, Dan, 

  

  

  

On N3752W, the only change to the plane was the cowling.  Right out of the hangar it was 5 knots (TAS) faster than the stock cowling at altitudes between  1500 feet and 5500 feet and 2700 rpm.  It was also easier to run past 2700 rpm at 8000 feet.  So, I don't know what to tell you.   

  

  

  

When I installed the very first one on N119ST, it was 9 knots (TAS) faster.  On my plane with a 65-63-61 prop, it was 10 knots (TAS) faster.  Both at 2700  rpm.  My old cowling, however, didn't fit well, was debonding and patched all over.   

  

  

  

I wish you were closer.   

  

  

  

Gary 

  

  

       

 

From: Dan Schmitz <Dan.Schmitz(at)calix.com (Dan.Schmitz(at)calix.com)>

 To: "teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)" <teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)> 

 Sent: Thursday, May 24, 2012 5:04 AM

 Subject: RE: Inlet Plugs for Jaguar Cowl on a Tiger 

 

      

If IAS is meaningless, then computing TAS off of IAS is a pointless exercise.  I was comparing IAS of density altitude to IAS of the same density altitude.  The TAS calculations  will work out to be the same in either case.  Note that I completely ignored the IAS in a number of test runs where I simply used GPS ground speed in 3 directions to compute a TAS using some fun formulas.  The numbers all come out to Ã¢â‚¬Å“no real changeÃ¢â‚¬ï¿½. 

  

  

  

Now, by the argument that a prop turning X RPM at Y density altitude will see no speed change even as there are drag reductionsÃ¢â‚¬Â¦um counter-intuitive, but my high altitude  tests up to 13,300Ã¢â‚¬â„¢ with new cowl so far show no changes either.  Of course, the problem with my high density altitude tests then are they are at Ã¢â‚¬Å“fullÃ¢â‚¬ï¿½  engine power, I lean for highest RPM in a speed test at higher altitudes.  I donÃ¢â‚¬â„¢t imagine my engine is doing its best with a cylinder being broken in (maybe) and running on mineral oil.  So thereÃ¢â‚¬â„¢s power IÃ¢â‚¬â„¢m not getting yet.  Do most Grummans see a  5 knot speedup after breaking in and switching to normal oil?   

  

  

  

Dan Schmitz 

  

Tiger 4518B 

  

KASH 

  

  

 

 

 

 

 

 

 

 

 	
 

 

   ï¿½ï¿½ï¿½~ï¿½ï¿½,ï¿½ï¿½ï¿½%ï¿½ï¿½4ï¿½M4}ï¿½rï¿½ï¿½ï¿½ï¿½ï¿½{(ï¿½ï¿½ï¿½ï¿½8^Mï¿½ï¿½ï¿½ï¿½ï¿½ËŠï¿½Dï¿½ï¿½ï¿½ï¿½ï¿½Kï¿½ï¿½jï¿½ï¿½',.+-æºï¿½ï¿½5ï¿½â«hï¿½ï¿½ï¿½ï¿½,zï¿½^ï¿½ï¿½ï¿½.+-ï¿½Ø¥ï¿½Øžï¿½Ëœï¿½ï¿½ï¿½ï¿½Tï¿½ï¿½nï¿½+ï¿½ï¿½bï¿½p+rï¿½y'ï¿½ï¿½ï¿½Cï¿½	å¡§{ ï¿½ï¿½ï¿½ï¿½,x(Zï¿½P>-ï¿½ï¿½Zï¿½ï¿½vkï¿½ï¿½kï¿½ï¿½j+yï¿½kyï¿½mï¿½ï¿½ï¿½ï¿½&jï¿½ï¿½',rï¿½ï¿½5ï¿½â«hï¿½7ï¿½ï¿½jï¿½fï¿½.+-ï¿½ï¿½iï¿½ï¿½0ï¿½fï¿½ï¿½ï¿½ï¿½rï¿½(ï¿½ï¿½Zï¿½(ï¿½ï¿½ï¿½yï¿½ï¿½ï¿½ï¿½jrï¿½ï¿½ï¿½0ï¿½8ï¿½Iaï¿½T1$ï¿½ï¿½ï¿½+yï¿½\ï¿½{^ï¿½Ö¥ï¿½ï¿½ï¿½j)ZnWï¿½ï¿½ï¿½aygï¿½ï¿½ï¿½Æ¡ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½+ï¿½k&jï¿½ï¿½',rï¿½ï¿½ï¿½ï¿½ï¿½ï¿½+ï¿½k&jï¿½ï¿½',rï¿½ï¿½hï¿½ï¿½ï¿½*'ï¿½ï¿½ï¿½ï¿½Ø¨ï¿½gï¿½J+^Nï¿½ï¿½*.~ï¿½ï¿½ï¿½ï¿½zwï¿½ï¿½ï¿½,ï¿½ï¿½hï¿½ï¿½ï¿½ï¿½ï¿½jY^.+-Ù¢ï¿½ï¿½kyï¿½mï¿½ï¿½ï¿½ï¿½&jï¿½ï¿½',rï¿½ï¿½rï¿½ï¿½&ï¿½*'ï¿½ï¿½iï¿½ï¿½0ï¿½fï¿½ï¿½ï¿½ï¿½rï¿½(ï¿½ï¿½(ï¿½ï¿½ï¿½nï¿½bï¿½ï¿½ï¿½ß¢{ï¿½ï¿½ï¿½nï¿½rï¿½f

[b]

Dan.Schmitz(at)calix.com
Guest

Posted: Fri May 25, 2012 8:22 am Post subject: Inlet Plugs for Jaguar Cowl on a Tiger

Look, if I take my wheel pants off and motor around at 2700 RPM, my plane is going to be several knots slower.  Then I reinstall my drag reducing wheel pants and 2700 RPM gets me more speed.  Iâ€™ve done this, I know itâ€™s true.  The cowl doesnâ€™t seem to have the same speed impact that wheel pants do.  I like the cowl, it has great benefits, but apparently, for me at least, cruise speed benefits are not part of the mix.



Dan



From: owner-teamgrumman-list-server(at)matronics.com [mailto:owner-teamgrumman-list-server(at)matronics.com] On Behalf Of 923TE

Sent: Friday, May 25, 2012 8:45 AM

To: teamgrumman-list(at)matronics.com

Subject: Re: TeamGrumman-List: Inlet Plugs for Jaguar Cowl on a Tiger



Dan the only way to get good results is at wide open throttle. You have no way of positively identifying when you are at 75% power in any consistent way. So if your "flight testing" was not done at wide open throttle and at the same best power setting then your data has no use in a pre - post Jaguar speed comparison. Calculated results just don't cut it.



When I change direction I fly for a minimum of 10 minutes on that new heading before I am confident that I am seeing a stabilized air speed. Flight testing is not really that easy to perform.



On May 25, 2012, at 6:52 AM, Dan Schmitz <Dan.Schmitz(at)calix.com<mailto:Dan.Schmitz(at)calix.com>> wrote:

Is that full throttle at sea level?  I should say that my 138 knots was staying within the bounds of 75% power.  If I did full power at 1000â€™ I expect Iâ€™d be in the low 140s for sure.  Donâ€™t know how high.



Dan



From: owner-teamgrumman-list-server(at)matronics.com<mailto:owner-teamgrumman-list-server(at)matronics.com> [mailto:owner-teamgrumman-list-server(at)matronics.com] On Behalf Of Gary L Vogt

Sent: Friday, May 25, 2012 1:46 AM

To: teamgrumman-list(at)matronics.com<mailto:teamgrumman-list(at)matronics.com>

Subject: Re: TeamGrumman-List: Inlet Plugs for Jaguar Cowl on a Tiger



N3752W: 144 knots

N1976T: 145 knots

N28747: 148 knots



If your plane is not 140 knots, something is wrong. What prop are you turning?

Gary

Sent from my iPad



On May 24, 2012, at 1:10 PM, Dan Schmitz <Dan.Schmitz(at)calix.com<mailto:Dan.Schmitz(at)calix.com>> wrote:

Me too (wish I was closer).  Iâ€™ll be at Oshkosh for the AYA convention.  Anyway what kind of speeds were you getting pre and post Jaguar?  My best speeds both pre and post are 138 knots.  Did your other planes go from 133 to 138?  Iâ€™ve always been able to run a bit over 2700 RPM at 8000â€™ and thatâ€™s with a 64â€ pitch sensenich.  Right about 9000â€™ DA is where full throttle equals 2700 RPM (strobe checked, not tach), again both before and after the new cowl.



Dan



From: owner-teamgrumman-list-server(at)matronics.com<mailto:owner-teamgrumman-list-server(at)matronics.com> [mailto:owner-teamgrumman-list-server(at)matronics.com] On Behalf Of Gary Vogt

Sent: Thursday, May 24, 2012 1:29 PM

To: teamgrumman-list(at)matronics.com<mailto:teamgrumman-list(at)matronics.com>

Subject: Re: TeamGrumman-List: Inlet Plugs for Jaguar Cowl on a Tiger



Well, Dan,



On N3752W, the only change to the plane was the cowling.  Right out of the hangar it was 5 knots (TAS) faster than the stock cowling at altitudes between 1500 feet and 5500 feet and 2700 rpm.  It was also easier to run past 2700 rpm at 8000 feet.  So, I don't know what to tell you.



When I installed the very first one on N119ST, it was 9 knots (TAS) faster.  On my plane with a 65-63-61 prop, it was 10 knots (TAS) faster.  Both at 2700 rpm.  My old cowling, however, didn't fit well, was debonding and patched all over.



I wish you were closer.



Gary



________________________________

From: Dan Schmitz <Dan.Schmitz(at)calix.com<mailto:Dan.Schmitz(at)calix.com>>

To: "teamgrumman-list(at)matronics.com<mailto:teamgrumman-list(at)matronics.com>" <teamgrumman-list(at)matronics.com<mailto:teamgrumman-list(at)matronics.com>>

Sent: Thursday, May 24, 2012 5:04 AM

Subject: RE: TeamGrumman-List: Inlet Plugs for Jaguar Cowl on a Tiger



If IAS is meaningless, then computing TAS off of IAS is a pointless exercise.  I was comparing IAS of density altitude to IAS of the same density altitude.  The TAS calculations will work out to be the same in either case.  Note that I completely ignored the IAS in a number of test runs where I simply used GPS ground speed in 3 directions to compute a TAS using some fun formulas.  The numbers all come out to Ã¢â‚¬Å“no real changeÃ¢â‚¬ï¿½.



Now, by the argument that a prop turning X RPM at Y density altitude will see no speed change even as there are drag reductionsÃ¢â‚¬Â¦um counter-intuitive, but my high altitude tests up to 13,300Ã¢â‚¬â„¢ with new cowl so far show no changes either.  Of course, the problem with my high density altitude tests then are they are at Ã¢â‚¬Å“fullÃ¢â‚¬ï¿½ engine power, I lean for highest RPM in a speed test at higher altitudes.  I donÃ¢â‚¬â„¢t imagine my engine is doing its best with a cylinder being broken in (maybe) and running on mineral oil.  So thereÃ¢â‚¬â„¢s power IÃ¢â‚¬â„¢m not getting yet.  Do most Grummans see a 5 knot speedup after breaking in and switching to normal oil?



Dan Schmitz

Tiger 4518B

KASH



ï¿½ï¿½ï¿½~ï¿½ï¿½,ï¿½ï¿½ï¿½%ï¿½ï¿½4ï¿½M4}ï¿½â€‘rï¿½ï¿½ï¿½ï¿½ï¿½{(ï¿½ï¿½ï¿½ï¿½8^Mï¿½ï¿½ï¿½ï¿½ï¿½ËŠï¿½Dï¿½ï¿½ï¿½ï¿½ï¿½Kâ€‘ï¿½ï¿½jï¿½ï¿½',.+-æºï¿½ï¿½5ï¿½â«hï¿½ï¿½ï¿½ï¿½,zï¿½^ï¿½ï¿½ï¿½.+-ï¿½Ø¥ï¿½Øžï¿½Ëœï¿½ï¿½

ï¿½ï¿½Tï¿½ï¿½nï¿½+ï¿½ï¿½bï¿½p+rï¿½y'ï¿½ï¿½ï¿½Cï¿½ å¡§{ ï¿½ï¿½ï¿½ï¿½,x(Zï¿½P>-ï¿½ï¿½Zï¿½ï¿½vkï¿½ï¿½kï¿½ï¿½j+yï¿½kyï¿½mï¿½ï¿½ï¿½ï¿½

&jï¿½ï¿½',rï¿½ï¿½5ï¿½â«hï¿½7ï¿½ï¿½jï¿½fï¿½.+-ï¿½ï¿½iï¿½ï¿½0ï¿½fï¿½ï¿½ï¿½ï¿½rï¿½(ï¿½ï¿½Zï¿½(ï¿½ï¿½ï¿½yï¿½ï¿½ï¿½ï¿½jrï¿½ï¿½ï¿½0ï¿½8ï¿½Iaï¿½T1$ï¿½ï¿½ï¿½+yï¿½\ï¿½{^ï¿½Ö¥ï¿½ï¿½ï¿½j)ZnWï¿½ï¿½ï¿½aygï¿½ï¿½ï¿½Æ¡ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½+ï¿½k&jï¿½ï¿½',rï¿½ï¿½ï¿½ï¿½ï¿½ï¿½+ï¿½k&jï¿½ï¿½',rï¿½ï¿½hï¿½ï¿½ï¿½*'ï¿½ï¿½ï¿½ï¿½Ø¨ï¿½gï¿½J+^Nï¿½ï¿½*.~ï¿½ï¿½ï¿½ï¿½zwï¿½ï¿½ï¿½,ï¿½ï¿½hï¿½ï¿½ï¿½ï¿½ï¿½jY^.+-Ù¢ï¿½ï¿½kyï¿½mï¿½ï¿½ï¿½ï¿½

&jï¿½ï¿½',rï¿½ï¿½rï¿½ï¿½&ï¿½*'ï¿½ï¿½iï¿½ï¿½0ï¿½fï¿½ï¿½ï¿½ï¿½rï¿½(ï¿½ï¿½(ï¿½ï¿½ï¿½nï¿½bï¿½ï¿½ï¿½ß¢{ï¿½ï¿½ï¿½nï¿½rï¿½f

teamgrumman(at)yahoo.com
Guest

Posted: Fri May 25, 2012 11:27 am Post subject: Inlet Plugs for Jaguar Cowl on a Tiger

Huh?  How can you tell if there is any difference if you are not full throttle?  Unless you have manifold pressure, fuel flow, and an accurate OAT, you have no way of knowing what your power setting is.

Flat out, WOT, 1000 feet, 2950 rpm, my plane's TAS is 159-160 knots.

        From: Dan Schmitz <Dan.Schmitz(at)calix.com>

 To: "teamgrumman-list(at)matronics.com" <teamgrumman-list(at)matronics.com> 

 Sent: Friday, May 25, 2012 4:52 AM

 Subject: RE: Inlet Plugs for Jaguar Cowl on a Tiger

           Is that full throttle at sea level?  I should say that my 138 knots was staying within the bounds of 75% power.  If I did full power at 1000Ã¢â‚¬â„¢ I expect IÃ¢â‚¬â„¢d be  in the low 140s for sure.  DonÃ¢â‚¬â„¢t know how high.

  Dan

     From: owner-teamgrumman-list-server(at)matronics.com [mailto:owner-teamgrumman-list-server(at)matronics.com] On Behalf Of Gary L Vogt

 Sent: Friday, May 25, 2012 1:46 AM

 To: teamgrumman-list(at)matronics.com

 Subject: Re: TeamGrumman-List: Inlet Plugs for Jaguar Cowl on a Tiger

   N3752W: 144 knots

  N1976T: 145 knots

  N28747: 148 knots

  If your plane is not 140 knots, something is wrong. What prop are you turning?

   Gary

 Sent from my iPad

 On May 24, 2012, at 1:10 PM, Dan Schmitz <Dan.Schmitz(at)calix.com (Dan.Schmitz(at)calix.com)> wrote:

  	  Quote: 	
		    Me too (wish I was closer).  IÃ¢â‚¬â„¢ll be at Oshkosh for the AYA convention.  Anyway what kind of speeds were you getting pre and post Jaguar?  My best speeds both  pre and post are 138 knots.  Did your other planes go from 133 to 138?  IÃ¢â‚¬â„¢ve always been able to run a bit over 2700 RPM at 8000Ã¢â‚¬â„¢ and thatÃ¢â‚¬â„¢s with a 64Ã¢â‚¬ï¿½ pitch sensenich.  Right about 9000Ã¢â‚¬â„¢ DA is where full throttle equals 2700 RPM (strobe checked, not tach),  again both before and after the new cowl.

  Dan

     From: owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com) [mailto:owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com)] On Behalf Of Gary Vogt

 Sent: Thursday, May 24, 2012 1:29 PM

 To: teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)

 Subject: Re: Inlet Plugs for Jaguar Cowl on a Tiger

    Well, Dan,

  On N3752W, the only change to the plane was the cowling.  Right out of the hangar it was 5 knots (TAS) faster than the stock cowling at altitudes between  1500 feet and 5500 feet and 2700 rpm.  It was also easier to run past 2700 rpm at 8000 feet.  So, I don't know what to tell you.  

  When I installed the very first one on N119ST, it was 9 knots (TAS) faster.  On my plane with a 65-63-61 prop, it was 10 knots (TAS) faster.  Both at 2700  rpm.  My old cowling, however, didn't fit well, was debonding and patched all over.  

  I wish you were closer.  

  Gary

 From: Dan Schmitz <Dan.Schmitz(at)calix.com (Dan.Schmitz(at)calix.com)>

 To: "teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)" <teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)> 

 Sent: Thursday, May 24, 2012 5:04 AM

 Subject: RE: Inlet Plugs for Jaguar Cowl on a Tiger

      If IAS is meaningless, then computing TAS off of IAS is a pointless exercise.  I was comparing IAS of density altitude to IAS of the same density altitude.  The TAS calculations  will work out to be the same in either case.  Note that I completely ignored the IAS in a number of test runs where I simply used GPS ground speed in 3 directions to compute a TAS using some fun formulas.  The numbers all come out to ÃƒÂ¢Ã¢â€šÂ¬Ã…â€œno real changeÃƒÂ¢Ã¢â€šÂ¬Ã¯Â¿Â½.

  Now, by the argument that a prop turning X RPM at Y density altitude will see no speed change even as there are drag reductionsÃƒÂ¢Ã¢â€šÂ¬Ã‚Â¦um counter-intuitive, but my high altitude  tests up to 13,300ÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢ with new cowl so far show no changes either.  Of course, the problem with my high density altitude tests then are they are at ÃƒÂ¢Ã¢â€šÂ¬Ã…â€œfullÃƒÂ¢Ã¢â€šÂ¬Ã¯Â¿Â½  engine power, I lean for highest RPM in a speed test at higher altitudes.  I donÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢t imagine my engine is doing its best with a cylinder being broken in (maybe) and running on mineral oil.  So thereÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢s power IÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢m not getting yet.  Do most Grummans see a  5 knot speedup after breaking in and switching to normal oil?  

  Dan Schmitz

  Tiger 4518B

  KASH

  Â¦Â·â€º~â€°ÃÂ²,Ãžg(â€“Å Ã“M4Ã“GÃšqÃ¼Â¢ÃªÃ¢zÂ¹ÃžÃÃŠ.Â®'Â«8^MÃ¦Â¦Â»Â¦â„¢Â©Ã‹Å Ã‹Dâ„¢Â¨Â¥Å Ã®ï¿½,zÃ˜^1Â«kÂ¢xÅ“Â°Â¸Â¬Â´WÅ¡Â¶ÃªÃžÂ°Ã–Â¯Å ÂÂ¢Â»hnÂº0Â±Ãâ€¦Ã©Å¡Å¸"Ã¢Â²Ã›ÂÅ XÂâ€°Ã«,Â¹ÃˆZÂ°Â¸Â¬ÂµIÃ¿JÃ¦Ã¬rÂ¸Â©Â¶*'

 [quote][b]

n26390(at)AOL.COM
Guest

Posted: Fri May 25, 2012 11:46 am Post subject: Inlet Plugs for Jaguar Cowl on a Tiger

2950 rpm (Seriously?)  In an airplane (Seriously?)  There's an STC for that (Seriously?)  Lycoming engine (Seriously?)  And parts aren't flying out of the engine (Seriously?)

 Seriously,

   Roger Rucker 

 AA5A '78 HWO

 

 

   --

teamgrumman(at)yahoo.com
Guest

Posted: Fri May 25, 2012 12:01 pm Post subject: Inlet Plugs for Jaguar Cowl on a Tiger

OK, I won't argue with you.  You just have a slow plane.  {smile}

        From: Dan Schmitz <Dan.Schmitz(at)calix.com>

 To: "teamgrumman-list(at)matronics.com" <teamgrumman-list(at)matronics.com> 

 Sent: Friday, May 25, 2012 9:18 AM

 Subject: RE: Inlet Plugs for Jaguar Cowl on a Tiger

  

 

          Look, if I take my wheel pants off and motor around at 2700 RPM, my plane is going to be several knots slower.  Then I reinstall my drag reducing wheel pants  and 2700 RPM gets me more speed.  IÃ¢â‚¬â„¢ve done this, I know itÃ¢â‚¬â„¢s true.  The cowl doesnÃ¢â‚¬â„¢t seem to have the same speed impact that wheel pants do.  I like the cowl, it has great benefits, but apparently, for me at least, cruise speed benefits are not part of the  mix.

    

  Dan

    

     From: owner-teamgrumman-list-server(at)matronics.com [mailto:owner-teamgrumman-list-server(at)matronics.com] On Behalf Of 923TE

 Sent: Friday, May 25, 2012 8:45 AM

 To: teamgrumman-list(at)matronics.com

 Subject: Re: Inlet Plugs for Jaguar Cowl on a Tiger

  

 

   

   Dan the only way to get good results is at wide open throttle. You have no way of positively identifying when you are at 75% power in any consistent way. So if your "flight testing" was not done at wide open throttle and at the same best  power setting then your data has no use in a pre - post Jaguar speed comparison. Calculated results just don't cut it.

  

    

  

  When I change direction I fly for a minimum of 10 minutes on that new heading before I am confident that I am seeing a stabilized air speed. Flight testing is not really that easy to perform.

  

  

 On May 25, 2012, at 6:52 AM, Dan Schmitz <Dan.Schmitz(at)calix.com (Dan.Schmitz(at)calix.com)> wrote:

  

  	  Quote: 	
		    Is that full throttle at sea level?  I should say that my 138 knots was staying within the bounds of 75% power.  If I did full power at 1000Ã¢â‚¬â„¢ I expect IÃ¢â‚¬â„¢d be  in the low 140s for sure.  DonÃ¢â‚¬â„¢t know how high.

   

  Dan

   

     From: owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com) [mailto:owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com)] On Behalf Of Gary L Vogt

 Sent: Friday, May 25, 2012 1:46 AM

 To: teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)

 Subject: Re: Inlet Plugs for Jaguar Cowl on a Tiger

  

 

  

   N3752W: 144 knots

  

  N1976T: 145 knots

  

  N28747: 148 knots

  

   

  

  If your plane is not 140 knots, something is wrong. What prop are you turning?

   Gary

  

 Sent from my iPad

  

  

 On May 24, 2012, at 1:10 PM, Dan Schmitz <Dan.Schmitz(at)calix.com (Dan.Schmitz(at)calix.com)> wrote:

  

  	  Quote: 	
		    Me too (wish I was closer).  IÃ¢â‚¬â„¢ll be at Oshkosh for the AYA convention.  Anyway what kind of speeds were you getting pre and post Jaguar?  My best speeds both  pre and post are 138 knots.  Did your other planes go from 133 to 138?  IÃ¢â‚¬â„¢ve always been able to run a bit over 2700 RPM at 8000Ã¢â‚¬â„¢ and thatÃ¢â‚¬â„¢s with a 64Ã¢â‚¬ï¿½ pitch sensenich.  Right about 9000Ã¢â‚¬â„¢ DA is where full throttle equals 2700 RPM (strobe checked, not tach),  again both before and after the new cowl.

   

  Dan

   

     From: owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com) [mailto:owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com)] On Behalf Of Gary Vogt

 Sent: Thursday, May 24, 2012 1:29 PM

 To: teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)

 Subject: Re: Inlet Plugs for Jaguar Cowl on a Tiger

  

 

  

    Well, Dan,

  

   

  

  On N3752W, the only change to the plane was the cowling.  Right out of the hangar it was 5 knots (TAS) faster than the stock cowling at altitudes between  1500 feet and 5500 feet and 2700 rpm.  It was also easier to run past 2700 rpm at 8000 feet.  So, I don't know what to tell you.  

  

   

  

  When I installed the very first one on N119ST, it was 9 knots (TAS) faster.  On my plane with a 65-63-61 prop, it was 10 knots (TAS) faster.  Both at 2700  rpm.  My old cowling, however, didn't fit well, was debonding and patched all over.  

  

   

  

  I wish you were closer.  

  

   

  

  Gary

  

   

  

       

 From: Dan Schmitz <Dan.Schmitz(at)calix.com (Dan.Schmitz(at)calix.com)>

 To: "teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)" <teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)> 

 Sent: Thursday, May 24, 2012 5:04 AM

 Subject: RE: Inlet Plugs for Jaguar Cowl on a Tiger

  

  

      If IAS is meaningless, then computing TAS off of IAS is a pointless exercise.  I was comparing IAS of density altitude to IAS of the same density altitude.  The TAS calculations  will work out to be the same in either case.  Note that I completely ignored the IAS in a number of test runs where I simply used GPS ground speed in 3 directions to compute a TAS using some fun formulas.  The numbers all come out to ÃƒÂ¢Ã¢â€šÂ¬Ã…â€œno real changeÃƒÂ¢Ã¢â€šÂ¬Ã¯Â¿Â½.

  

   

  

  Now, by the argument that a prop turning X RPM at Y density altitude will see no speed change even as there are drag reductionsÃƒÂ¢Ã¢â€šÂ¬Ã‚Â¦um counter-intuitive, but my high altitude  tests up to 13,300ÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢ with new cowl so far show no changes either.  Of course, the problem with my high density altitude tests then are they are at ÃƒÂ¢Ã¢â€šÂ¬Ã…â€œfullÃƒÂ¢Ã¢â€šÂ¬Ã¯Â¿Â½  engine power, I lean for highest RPM in a speed test at higher altitudes.  I donÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢t imagine my engine is doing its best with a cylinder being broken in (maybe) and running on mineral oil.  So thereÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢s power IÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢m not getting yet.  Do most Grummans see a  5 knot speedup after breaking in and switching to normal oil?  

  

   

  

  Dan Schmitz

  

  Tiger 4518B

  

  KASH

  

   

  

 

 

 

 

 

 

 

 

 	
 

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 http://www.matronics.com/Navigator?TeamGrumman-List[/b]</       - MATRONICS WEB FORUMS -[/b][/quote]  "nofollow" target="_blank" href="http://forums.matronics.com">http://fo          - List Contribution nbsp;                      -Matt Dralle, Listarget="_blank" href="http://www.matronics.com/contribution">http://www.===[/b]  [/quote]  

 

 

  Â¦Â·â€º~â€°ÃÂ²,Ãžg(â€“Å Ã“M4Ã“GÃšqÃ¼Â¢ÃªÃ¢zÂ¹ÃžÃÃŠ.Â®'Â«8^MÃ¦Â¦Â»Â¦â„¢Â©Ã‹Å Ã‹Dâ„¢Â¨Â¥Å Ã®ï¿½,zÃ˜^1Â«kÂ¢xÅ“Â°Â¸Â¬Â´WÅ¡Â¶ÃªÃžÂ°Ã–Â¯Å ÂÂ¢Â»hnÂº0Â±Ãâ€¦Ã©Å¡Å¸"Ã¢Â²Ã›ÂÅ XÂâ€°Ã«,Â¹ÃˆZÂ°Â¸Â¬ÂµIÃ¿JÃ¦Ã¬rÂ¸Â©Â¶*'

 

 

  

 [quote][b]

teamgrumman(at)yahoo.com
Guest

Posted: Fri May 25, 2012 12:18 pm Post subject: Inlet Plugs for Jaguar Cowl on a Tiger

I ran my O320 to 3150 rpm.

Valve float starts at 3400 so stay below that.

        From: "n26390(at)aol.com" <n26390(at)aol.com>

 To: teamgrumman-list(at)matronics.com 

 Sent: Friday, May 25, 2012 12:44 PM

 Subject: Re: Inlet Plugs for Jaguar Cowl on a Tiger

  

 

2950 rpm (Seriously?)  In an airplane (Seriously?)  There's an STC for that (Seriously?)  Lycoming engine (Seriously?)  And parts aren't flying out of the engine (Seriously?)

 Seriously,

   Roger Rucker 

 AA5A '78 HWO

 

 

   --

n76lima(at)mindspring.com
Guest

Posted: Fri May 25, 2012 2:48 pm Post subject: Inlet Plugs for Jaguar Cowl on a Tiger

Some of the AYA air racers turn 3,000+ RPM.  The engine is not the worry, it is the PROP!  Some have a tendency to throw a few inches off the tip, which is enough to rip the engine off the mount from the imbalance.

Just one more reason I don't fly in those planes...

--Bob Steward

n26390(at)AOL.COM wrote:



[quote]2950 rpm (Seriously?)  In an airplane (Seriously?)  There's an STC for that (Seriously?)  Lycoming engine (Seriously?)  And parts aren't flying out of the engine (Seriously?)

Seriously,



Roger Rucker 

AA5A '78 HWO



--

Discover

Joined: 26 Feb 2007
Posts: 429

Posted: Fri May 25, 2012 8:30 pm Post subject: Inlet Plugs for Jaguar Cowl on a Tiger

If you want to maintain a constant RPM before and after drag reduction then your throttle would be less open in the less drag configuration. That's why you must have exactly the same throttle position to have a meaningful comparison of speeds



On May 25, 2012, at 11:18 AM, Dan Schmitz <Dan.Schmitz(at)calix.com (Dan.Schmitz(at)calix.com)> wrote:



 	  Quote: 	
		      v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} <![endif]-->  <![endif]-->   <![endif]-->    

Look, if I take my wheel pants off and motor around at 2700 RPM, my plane is going to be several knots slower.  Then I reinstall my drag reducing wheel pants  and 2700 RPM gets me more speed.  Iâ€™ve done this, I know itâ€™s true.  The cowl doesnâ€™t seem to have the same speed impact that wheel pants do.  I like the cowl, it has great benefits, but apparently, for me at least, cruise speed benefits are not part of the  mix. 

  

Dan 

     

From: owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com) [mailto:owner-teamgrumman-list-server(at)matronics.com] On Behalf Of 923TE

 Sent: Friday, May 25, 2012 8:45 AM

 To: teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)

 Subject: Re: Inlet Plugs for Jaguar Cowl on a Tiger 

 

 

   

Dan the only way to get good results is at wide open throttle. You have no way of positively identifying when you are at 75% power in any consistent way. So if your "flight testing" was not done at wide open throttle and at the same best  power setting then your data has no use in a pre - post Jaguar speed comparison. Calculated results just don't cut it. 

  

  

  

When I change direction I fly for a minimum of 10 minutes on that new heading before I am confident that I am seeing a stabilized air speed. Flight testing is not really that easy to perform. 

  



 On May 25, 2012, at 6:52 AM, Dan Schmitz <Dan.Schmitz(at)calix.com (Dan.Schmitz(at)calix.com)> wrote: 

  	  Quote: 	
		    

Is that full throttle at sea level?  I should say that my 138 knots was staying within the bounds of 75% power.  If I did full power at 1000â€™ I expect Iâ€™d be  in the low 140s for sure.  Donâ€™t know how high. 

  

Dan 

     

From: owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com) [mailto:owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com)] On Behalf Of Gary L Vogt

 Sent: Friday, May 25, 2012 1:46 AM

 To: teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)

 Subject: Re: Inlet Plugs for Jaguar Cowl on a Tiger 

 

 

   

N3752W: 144 knots 

  

N1976T: 145 knots 

  

N28747: 148 knots 

  

  

  

If your plane is not 140 knots, something is wrong. What prop are you turning?  

Gary 

 

Sent from my iPad 

  



 On May 24, 2012, at 1:10 PM, Dan Schmitz <Dan.Schmitz(at)calix.com (Dan.Schmitz(at)calix.com)> wrote: 

  	  Quote: 	
		    

Me too (wish I was closer).  Iâ€™ll be at Oshkosh for the AYA convention.  Anyway what kind of speeds were you getting pre and post Jaguar?  My best speeds both  pre and post are 138 knots.  Did your other planes go from 133 to 138?  Iâ€™ve always been able to run a bit over 2700 RPM at 8000â€™ and thatâ€™s with a 64â€ pitch sensenich.  Right about 9000â€™ DA is where full throttle equals 2700 RPM (strobe checked, not tach),  again both before and after the new cowl. 

  

Dan 

     

From: owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com) [mailto:owner-teamgrumman-list-server(at)matronics.com (owner-teamgrumman-list-server(at)matronics.com)] On Behalf Of Gary Vogt

 Sent: Thursday, May 24, 2012 1:29 PM

 To: teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)

 Subject: Re: Inlet Plugs for Jaguar Cowl on a Tiger 

 

 

    

Well, Dan, 

  

  

  

On N3752W, the only change to the plane was the cowling.  Right out of the hangar it was 5 knots (TAS) faster than the stock cowling at altitudes between  1500 feet and 5500 feet and 2700 rpm.  It was also easier to run past 2700 rpm at 8000 feet.  So, I don't know what to tell you.   

  

  

  

When I installed the very first one on N119ST, it was 9 knots (TAS) faster.  On my plane with a 65-63-61 prop, it was 10 knots (TAS) faster.  Both at 2700  rpm.  My old cowling, however, didn't fit well, was debonding and patched all over.   

  

  

  

I wish you were closer.   

  

  

  

Gary 

  

  

       

 

From: Dan Schmitz <Dan.Schmitz(at)calix.com (Dan.Schmitz(at)calix.com)>

 To: "teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)" <teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)> 

 Sent: Thursday, May 24, 2012 5:04 AM

 Subject: RE: Inlet Plugs for Jaguar Cowl on a Tiger 

 

      

If IAS is meaningless, then computing TAS off of IAS is a pointless exercise.  I was comparing IAS of density altitude to IAS of the same density altitude.  The TAS calculations  will work out to be the same in either case.  Note that I completely ignored the IAS in a number of test runs where I simply used GPS ground speed in 3 directions to compute a TAS using some fun formulas.  The numbers all come out to Ã¢â‚¬Å“no real changeÃ¢â‚¬ï¿½. 

  

  

  

Now, by the argument that a prop turning X RPM at Y density altitude will see no speed change even as there are drag reductionsÃ¢â‚¬Â¦um counter-intuitive, but my high altitude  tests up to 13,300Ã¢â‚¬â„¢ with new cowl so far show no changes either.  Of course, the problem with my high density altitude tests then are they are at Ã¢â‚¬Å“fullÃ¢â‚¬ï¿½  engine power, I lean for highest RPM in a speed test at higher altitudes.  I donÃ¢â‚¬â„¢t imagine my engine is doing its best with a cylinder being broken in (maybe) and running on mineral oil.  So thereÃ¢â‚¬â„¢s power IÃ¢â‚¬â„¢m not getting yet.  Do most Grummans see a  5 knot speedup after breaking in and switching to normal oil?   

  

  

  

Dan Schmitz 

  

Tiger 4518B 

  

KASH 

  

  

 

 

 

 

 

 

 

 

 	
 

 

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 ======================================[/b] 	
 amGrumman-List Email Forum -[/b][/quote] [/b][/quote] p>[/b][/quote] o:p>[/b][/quote] or?TeamGrumman-List">http://www.matronics.com/Navigator?TeamGrumman-List[/b][/quote] ======================================[/b][/quote] sp;    - MATRONICS WEB FORUMS -[/b][/quote] p>[/b][/quote] p://forums.matronics.com[/b][/quote] ======================================[/b][/quote] sp;  - List Contribution Web Site -[/b][/quote] > sp;                   -Matt Dralle, List Admin.[/b][/quote] ution">http://www.matronics.com/contribution[/b][/quote] ======================================[/b] [/quote] 

 

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[b]

Discover

Joined: 26 Feb 2007
Posts: 429

Posted: Sat May 26, 2012 4:28 am Post subject: Inlet Plugs for Jaguar Cowl on a Tiger

Some of the Benefits of the MT prop when racing are: it's certified for 225 HP at 2800 rpm and 300 HP at 2700 RPM it has a smaller diameter than the fixed pitch Tiger prop so tip speeds are slower and it causes less fuel burn for a given speed than the fixed pitch prop. Since its blade weighs less than the metal blade a broken tip would have less affect and perhaps not be the disaster a metal tip break  

On May 25, 2012, at 5:46 PM, Bob Steward <n76lima(at)mindspring.com (n76lima(at)mindspring.com)> wrote:



[quote]--> TeamGrumman-List message posted by: Bob Steward <n76lima(at)mindspring.com (n76lima(at)mindspring.com)>



Some of the AYA air racers turn 3,000+ RPM.  The engine is not the worry, it is the PROP!  Some have a tendency to throw a few inches off the tip, which is enough to rip the engine off the mount from the imbalance.

Just one more reason I don't fly in those planes...

--Bob Steward

n26390(at)AOL.COM (n26390(at)AOL.COM) wrote:



[quote]2950 rpm (Seriously?)  In an airplane (Seriously?)  There's an STC for that (Seriously?)  Lycoming engine (Seriously?)  And parts aren't flying out of the engine (Seriously?)

Seriously,



Roger Rucker 

AA5A '78 HWO



--

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