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mr.sun
Joined: 30 Jan 2007 Posts: 85
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Posted: Sat May 12, 2007 11:43 am Post subject: Performance Chart |
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I'm flying a 1160 lb RV-7 with Hartzell Blended Airfoil Constant Speed Prop, Aerosport IO-360 180 hp engine, Lightspeed Ignition with wheelpants & standard fairings installed. Does anyone have a similar plane with verified performance numbers? I don't believe the original builder's RPM vs MP vs GPH numbers. Thanks, Greg
[quote][b]
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pilots2(at)yahoo.com Guest
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Posted: Sat May 12, 2007 6:44 pm Post subject: Performance Chart |
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Greg,
Got almost the same setup in a 7A but with mags. We had the same questions a year and a half ago. Called Lycoming and had them send an 8 1/2" by 11" power chart (the original is a 5 x 8 sheet that is all but unreadable and unuseable) for an IO360 and used that to start with. Would have no clue on how the Lightspeed would affect the power chart. We use 22" at 2400 rpm and I believe that is around 75% and the fuel flow gauge reads 10gph. Can obviously get it down lower if we use 20" or even 18" for sigh-seeing cruse. The bottom line is that you are pretty much on your own to figure the power setting out.
Reuven Silberman
NWT
Greg Williams <mr.gsun(at)gmail.com> wrote:[quote] I'm flying a 1160 lb RV-7 with Hartzell Blended Airfoil Constant Speed Prop, Aerosport IO-360 180 hp engine, Lightspeed Ignition [quote][b]
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khorton01(at)rogers.com Guest
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Posted: Sat May 12, 2007 7:19 pm Post subject: Performance Chart |
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On 12 May 2007, at 15:40, Greg Williams wrote:
Quote: | I'm flying a 1160 lb RV-7 with Hartzell Blended Airfoil Constant
Speed Prop, Aerosport IO-360 180 hp engine, Lightspeed Ignition
with wheelpants & standard fairings installed. Does anyone have a
similar plane with verified performance numbers? I don't believe
the original builder's RPM vs MP vs GPH numbers.
|
The RPM vs MP vs GPH relationship should be independent of the prop,
aircraft model and weight.
What RPM vs MP vs GPH numbers does the original builder quote, and
what do you think they should be? What leaning technique are you
using? What altitude and temperature did you use for your testing?
How accurate is your fuel flow indicator, based on the errors in fuel
needed to fill the tanks after a flight?
Kevin Horton RV-8 (finishing kit)
Ottawa, Canada
http://www.kilohotel.com/rv8
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mr.gsun+rv-list(at)gmail. Guest
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Posted: Sat May 12, 2007 7:31 pm Post subject: Performance Chart |
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Hey, Thank you. It's better than what I've got now, I think. I'll try your numbers and see what happens. I would like to figure it out but don't really know where to start. The chart that I was given reads as below:
Cruise Performance at 8,000':
KIAS
RPM
MAP
Fuel Flow
% Power
168
2550
22.5
10.1 GPH
75%
161
2350
22.5
8.5 GPH
65%
150
2400
20.0
6.8 GPH
55%
What do you think?
I can't get anywhere near 168 KIAS with these 75% power settings.
Greg
On 5/12/07, Reuven Silberman <pilots2(at)yahoo.com (pilots2(at)yahoo.com)> wrote: Quote: | Greg,
Got almost the same setup in a 7A but with mags. We had the same questions a year and a half ago. Called Lycoming and had them send an 8 1/2" by 11" power chart (the original is a 5 x 8 sheet that is all but unreadable and unuseable) for an IO360 and used that to start with. Would have no clue on how the Lightspeed would affect the power chart. We use 22" at 2400 rpm and I believe that is around 75% and the fuel flow gauge reads 10gph. Can obviously get it down lower if we use 20" or even 18" for sigh-seeing cruse. The bottom line is that you are pretty much on your own to figure the power setting out.
Reuven Silberman
NWT
Greg Williams <mr.gsun(at)gmail.com (mr.gsun(at)gmail.com)> wrote: Quote: | I'm flying a 1160 lb RV-7 with Hartzell Blended Airfoil Constant Speed Prop, Aerosport IO-360 180 hp engine, Lightspeed Ignition
[/b] |
| [b]
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mr.gsun+rv-list(at)gmail. Guest
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Posted: Sat May 12, 2007 7:43 pm Post subject: Performance Chart |
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Kevin, Thanks for the info. I just posted the chart I was given. I've tried it recently at 8000 ft. It was 36 deg F outside. I leaned it until RPM dropped a bit then back up just a tad (very unscientific, I agree). The EGT temp readouts are kind of slow to change so I haven't yet got "rich of peak" figured out. The engine seems to run just fine at the settings I've been given. Just doesn't agree with IAS numbers or GPS numbers on a calm day.
Appreciate your expertise.
Greg
On 5/12/07, Kevin Horton <khorton01(at)rogers.com (khorton01(at)rogers.com)> wrote:[quote] --> RV-List message posted by: Kevin Horton <khorton01(at)rogers.com (khorton01(at)rogers.com)>
On 12 May 2007, at 15:40, Greg Williams wrote:
Quote: | I'm flying a 1160 lb RV-7 with Hartzell Blended Airfoil Constant
Speed Prop, Aerosport IO-360 180 hp engine, Lightspeed Ignition
with wheelpants & standard fairings installed. Does anyone have a
similar plane with verified performance numbers? I don't believe
the original builder's RPM vs MP vs GPH numbers.
|
The RPM vs MP vs GPH relationship should be independent of the prop,
aircraft model and weight.
What RPM vs MP vs GPH numbers does the original builder quote, and
what do you think they should be? What leaning technique are you
using? What altitude and temperature did you use for your testing?
How accurate is your fuel flow indicator, based on the errors in fuel
needed to fill the tanks after a flight?
[b]
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Vanremog(at)aol.com Guest
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Posted: Sat May 12, 2007 8:08 pm Post subject: Performance Chart |
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In a message dated 5/12/2007 8:33:02 P.M. Pacific Daylight Time, mr.gsun+rv-list(at)gmail.com writes:
Quote: |
Cruise Performance at 8,000':
KIAS
RPM
MAP
Fuel Flow
% Power
168
2550
22.5
10.1 GPH
75%
161
2350
22.5
8.5 GPH
65%
150
2400
20.0
6.8 GPH
55%
What do you think?
I can't get anywhere near 168 KIAS with these 75% power settings.
|
==========================
My 6A is pretty much in agreement with this data.
GV (RV-6A N1GV O-360-A1A, C/S, Flying 845hrs, Silicon Valley, CA)
See what's free at AOL.com.
[quote][b]
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pilots2(at)yahoo.com Guest
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Posted: Sat May 12, 2007 8:26 pm Post subject: Performance Chart |
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Greg,
Should have added additional info. At 24" / 2400 we consistantly true out at 180K above 5,000 ft. Obviously the gas consumption is wallet busting. At 22" / 2400 we consistantly get 170K true at the prev mentioned 10gph. 20" / 2400 gets in the 160 - 165K range and a more reasonable 8 to 9 gph.
Reuven
Greg Williams <mr.gsun+rv-list(at)gmail.com> wrote:[quote] Hey, Thank you. It's better than what I've got now, I think. I'll try your numbers and see what happens. I would like to figure it out but don't really know where to start. The chart that I was given reads as below:
Cruise Performance at 8,000':
KIAS
RPM
MAP
Fuel Flow
% Power
168
2550
22.5
10.1 GPH
75%
161
2350
22.5
8.5 GPH
65%
150
2400
20.0
6.8 GPH
55%
What do you think?
I can't get anywhere near 168 KIAS with these 75% power settings.
Greg
On 5/12/07, Reuven Silberman <pilots2(at)yahoo.com (pilots2(at)yahoo.com)> wrote:[quote] Greg,
Got almost the same setup in a 7A but with mags. We had the same questions a year and a half ago. Called Lycoming and had them send an 8 1/2" by 11" power chart (the original is a 5 x 8 sheet that is all but unreadable and unuseable) for an IO360 and used that to start with. Would have no clue on how the Lightspeed would affect the power chart. We use 22" at 2400 rpm and I believe that is around 75% and the fuel flow gauge reads 10gph. Can obviously get it down lower if we use 20" or even 18" for sigh-seeing cruse. The bottom line is that you are pretty much on your own to figure the power setting out.
Reuven Silberman
NWT
Greg Williams <mr.gsun(at)gmail.com (mr.gsun(at)gmail.com)> wrote: Quote: | I'm flying a 1160 lb RV-7 with Hartzell Blended Airfoil Constant Speed Prop, Aerosport IO-360 180 hp engine, Lightspeed Ignition
| [b] [quote][b]
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dale1rv6(at)comcast.net Guest
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Posted: Sat May 12, 2007 8:36 pm Post subject: Performance Chart |
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At standard temp (approx 32-35 F) and 8,000 MSL does 168 KIAS equal 188-190 knots true airspeed? The typical 6A with 180hp does not accomplish this, IMHO.
Dale
Do not archive
From: owner-rv-list-server(at)matronics.com [mailto:owner-rv-list-server(at)matronics.com] On Behalf Of Vanremog(at)aol.com
Sent: Sunday, May 13, 2007 12:08 AM
To: rv-list(at)matronics.com
Subject: Re: Performance Chart
In a message dated 5/12/2007 8:33:02 P.M. Pacific Daylight Time, mr.gsun+rv-list(at)gmail.com writes:
Quote: |
Cruise Performance at 8,000':
KIAS
RPM
MAP
Fuel Flow
% Power
168
2550
22.5
10.1 GPH
75%
161
2350
22.5
8.5 GPH
65%
150
2400
20.0
6.8 GPH
55%
What do you think?
I can't get anywhere near 168 KIAS with these 75% power settings. |
==========================
My 6A is pretty much in agreement with this data.
GV (RV-6A N1GV O-360-A1A, C/S, Flying 845hrs, Silicon Valley, CA)
See what's free at AOL.com.
Quote: | http://www.matronics.com/Navigator?RV-List | 01234
[quote][b]
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khorton01(at)rogers.com Guest
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Posted: Sun May 13, 2007 4:55 pm Post subject: Performance Chart |
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Just for reference, if you are leaned to best power, the Lycoming
power charts for the 200 hp IO-360-A says that 2400 rpm and 22" at
8000 ft gives 69% power at standard temperature. If you have a 180
hp parallel valve O-360-A (and I assume that the parallel valve 180
hp IO-360-Bs would be similar to the O-360), the same rpm and MP
gives 75% power.
It is interesting that at 8000 ft, for the same rpm and MP, the 200
hp angle valve engine makes less power than the 180 hp parallel valve
engine if the rpm is less than about 2350. Once the rpm is up, the
angle valve engine breaths better, and it makes more power than the
parallel valve one.
If your 180 hp parallel valve engine is leaned to best power at 8000
ft, on a standard day, 2550 and 22.5" = 144 hp (80%)
2350 and 22.5" = 138 hp (77%)
2400 and 20" = 120 (67%)
If you leaner than best power mixture (as defined in the Lycoming
Operators Manual), then the power will be a bit less than that.
If you are running lean of peak, I think your specific fuel
consumption would be somewhere in the range of 0.45 lb/hr per hp.
Avgas weighs 6 lb/USG. So, you can multiply the fuel flows (in USG/
hr) by 6/0.45 (=13.3) to get an approximate power in hp. Or, looked
at another way, if you have a a 180 hp engine, and you want 75% power
(135 hp), find a power setting that gives around 135/13.3 = 10.1 USG/
hr (only valid if mixture is leaner than mixture for best power).
This won't work if your mixture is richer than the mixture for best
power, as in this case not all the fuel is being burnt, and the SFC
will vary as the mixture varies.
Note: the exact SFC to expect varies depending on which reference you
read. Pick the reference you believe, and adjust the above numbers
to suit).
Kevin Horton
Ottawa, Canada
On 12 May 2007, at 23:30, Greg Williams wrote:
Quote: | Hey, Thank you. It's better than what I've got now, I think.
I'll try your numbers and see what happens. I would like to figure
it out but don't really know where to start. The chart that I was
given reads as below:
Cruise Performance at 8,000':
KIAS
RPM
MAP
Fuel Flow
% Power
168
2550
22.5
10.1 GPH
75%
161
2350
22.5
8.5 GPH
65%
150
2400
20.0
6.8 GPH
55%
What do you think?
I can't get anywhere near 168 KIAS with these 75% power settings.
Greg
On 5/12/07, Reuven Silberman <pilots2(at)yahoo.com> wrote: Greg,
Got almost the same setup in a 7A but with mags. We had the same
questions a year and a half ago. Called Lycoming and had them send
an 8 1/2" by 11" power chart (the original is a 5 x 8 sheet that is
all but unreadable and unuseable) for an IO360 and used that to
start with. Would have no clue on how the Lightspeed would affect
the power chart. We use 22" at 2400 rpm and I believe that is
around 75% and the fuel flow gauge reads 10gph. Can obviously get
it down lower if we use 20" or even 18" for sigh-seeing cruse.
The bottom line is that you are pretty much on your own to figure
the power setting out.
Reuven Silberman
NWT
Greg Williams <mr.gsun(at)gmail.com > wrote: I'm flying a 1160 lb RV-7
with Hartzell Blended Airfoil Constant Speed Prop, Aerosport IO-360
180 hp engine, Lightspeed Ignition
|
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mr.gsun+rv-list(at)gmail. Guest
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Posted: Mon May 14, 2007 7:41 am Post subject: Performance Chart |
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Wow, Thanks for all that tech info. I took notes and will digest it. As long as you're at it, what's the best way to lean the engine? My EFIS tells me all four EGT's but they react fairly slowly, and bounce around a bit. I'm not experienced enough to concentrate on watching for the peak numbers and fly the plane and chew bubble gum at the same time. Greg
On 5/13/07, Kevin Horton <khorton01(at)rogers.com (khorton01(at)rogers.com)> wrote:[quote] --> RV-List message posted by: Kevin Horton <khorton01(at)rogers.com (khorton01(at)rogers.com)>
Just for reference, if you are leaned to best power, the Lycoming
power charts for the 200 hp IO-360-A says that 2400 rpm and 22" at
8000 ft gives 69% power at standard temperature. If you have a 180
hp parallel valve O-360-A (and I assume that the parallel valve 180
hp IO-360-Bs would be similar to the O-360), the same rpm and MP
gives 75% power.
It is interesting that at 8000 ft, for the same rpm and MP, the 200
hp angle valve engine makes less power than the 180 hp parallel valve
engine if the rpm is less than about 2350. Once the rpm is up, the
angle valve engine breaths better, and it makes more power than the
parallel valve one.
If your 180 hp parallel valve engine is leaned to best power at 8000
ft, on a standard day, 2550 and 22.5" = 144 hp (80%)
2350 and 22.5" = 138 hp (77%)
2400 and 20" = 120 (67%)
If you leaner than best power mixture (as defined in the Lycoming
Operators Manual), then the power will be a bit less than that.
If you are running lean of peak, I think your specific fuel
consumption would be somewhere in the range of 0.45 lb/hr per hp.
Avgas weighs 6 lb/USG. So, you can multiply the fuel flows (in USG/
hr) by 6/0.45 (=13.3) to get an approximate power in hp. Or, looked
at another way, if you have a a 180 hp engine, and you want 75% power
(135 hp), find a power setting that gives around 135/13.3 = 10.1 USG/
hr (only valid if mixture is leaner than mixture for best power).
This won't work if your mixture is richer than the mixture for best
power, as in this case not all the fuel is being burnt, and the SFC
will vary as the mixture varies.
Note: the exact SFC to expect varies depending on which reference you
read. Pick the reference you believe, and adjust the above numbers
to suit).
Kevin Horton
Ottawa, Canada
On 12 May 2007, at 23:30, Greg Williams wrote:
Quote: | Hey, Thank you. It's better than what I've got now, I think.
I'll try your numbers and see what happens. I would like to figure
it out but don't really know where to start. The chart that I was
given reads as below:
Cruise Performance at 8,000':
KIAS
RPM
MAP
Fuel Flow
% Power
168
2550
22.5
10.1 GPH
75%
161
2350
22.5
>
|
Quote: | 8.5 GPH
65%
150
2400
20.0
6.8 GPH
55%
What do you think?
I can't get anywhere near 168 KIAS with these 75% power settings.
Greg
On 5/12/07, Reuven Silberman <pilots2(at)yahoo.com (pilots2(at)yahoo.com)> wrote: Greg,
Got almost the same setup in a 7A but with mags. We had the same
questions a year and a half ago. Called Lycoming and had them send
an 8 1/2" by 11" power chart (the original is a 5 x 8 sheet that is
all but unreadable and unuseable) for an IO360 and used that to
start with. Would have no clue on how the Lightspeed would affect
the power chart. We use 22" at 2400 rpm and I believe that is
around 75% and the fuel flow gauge reads 10gph. Can obviously get
it down lower if we use 20" or even 18" for sigh-seeing cruse.
The bottom line is that you are pretty much on your own to figure
the power setting out.
Reuven Silberman
> NWT
|
[quote]
Greg Williams <mr.gsun(at)gmail.com (mr.gsun(at)gmail.com) > wrote: I'm flying a 1160 lb RV-7
with Hartzell Blended Airfoil Constant Speed Prop, Aerosport IO-360
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khorton01(at)rogers.com Guest
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Posted: Mon May 14, 2007 2:44 pm Post subject: Performance Chart |
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|
Sorry, I'm no expert on leaning. The vast majority of my time is in
aircraft powered by turbines or big radial. My light piston time is
all in aircraft with no EGT gauge. I've got a Grand Rapids EIS 4000
in my RV-8 project, and its leaning function is one of the reasons
why I went with it. You manually switch it to leaning mode, and then
it picks up which EGT is first to peak, and then it tells you how
many degrees rich or lean of peak the EGT of that cylinder is.
Some manufacturers advertise that their EGT probes have a fast
response, but I honestly don't know if there are any real
differences, or if this is just marketing hype.
One idea to try - some day when you have some time, establish a
typical cruise altitude and power. Then, very slowly, lean, watching
all EGTs and note which one peaks first. See if this is repeatable,
even at different power settings. If you have one cylinder that
always peaks first, then maybe you can simplify things a bit by
paying more attention to that one cylinder. Also, if you have one or
two different power settings that you like to use, note the fuel flow
reading when the first cylinder peaks. Then, in the future, you
could lean rapidly until the fuel flow is a bit more than this value,
pause for the EGTs to stabilize, then lean more slowly to catch the
peak EGT. I've never tried this, as I don't fly an aircraft with an
EGT gauge, so I don't know how well it will work. I offer it for your
consideration. The only piston-powered aircraft I am flying at the
moment is an old C182.
Kevin Horton
On 14 May 2007, at 11:40, Greg Williams wrote:
Quote: | Wow, Thanks for all that tech info. I took notes and will digest
it. As long as you're at it, what's the best way to lean the
engine? My EFIS tells me all four EGT's but they react fairly
slowly, and bounce around a bit. I'm not experienced enough to
concentrate on watching for the peak numbers and fly the plane and
chew bubble gum at the same time. Greg
On 5/13/07, Kevin Horton <khorton01(at)rogers.com> wrote: --> RV-List
message posted by: Kevin Horton <khorton01(at)rogers.com>
Just for reference, if you are leaned to best power, the Lycoming
power charts for the 200 hp IO-360-A says that 2400 rpm and 22" at
8000 ft gives 69% power at standard temperature. If you have a 180
hp parallel valve O-360-A (and I assume that the parallel valve 180
hp IO-360-Bs would be similar to the O-360), the same rpm and MP
gives 75% power.
It is interesting that at 8000 ft, for the same rpm and MP, the 200
hp angle valve engine makes less power than the 180 hp parallel valve
engine if the rpm is less than about 2350. Once the rpm is up, the
angle valve engine breaths better, and it makes more power than the
parallel valve one.
If your 180 hp parallel valve engine is leaned to best power at 8000
ft, on a standard day, 2550 and 22.5" = 144 hp (80%)
2350 and 22.5" = 138 hp (77%)
2400 and 20" = 120 (67%)
If you leaner than best power mixture (as defined in the Lycoming
Operators Manual), then the power will be a bit less than that.
If you are running lean of peak, I think your specific fuel
consumption would be somewhere in the range of 0.45 lb/hr per hp.
Avgas weighs 6 lb/USG. So, you can multiply the fuel flows (in USG/
hr) by 6/0.45 (=13.3) to get an approximate power in hp. Or, looked
at another way, if you have a a 180 hp engine, and you want 75% power
(135 hp), find a power setting that gives around 135/13.3 = 10.1 USG/
hr (only valid if mixture is leaner than mixture for best power).
This won't work if your mixture is richer than the mixture for best
power, as in this case not all the fuel is being burnt, and the SFC
will vary as the mixture varies.
Note: the exact SFC to expect varies depending on which reference you
read. Pick the reference you believe, and adjust the above numbers
to suit).
Kevin Horton
Ottawa, Canada
|
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