---------------------------------------------------------- RV10-List Digest Archive --- Total Messages Posted Sun 06/30/13: 3 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 03:10 PM - Fuel Question (Dave Saylor) 2. 08:43 PM - Re: Fuel Question (woxofswa) 3. 08:45 PM - Re: Fuel Question (Bob Turner) ________________________________ Message 1 _____________________________________ Time: 03:10:30 PM PST US From: Dave Saylor Subject: RV10-List: Fuel Question A little background: we just finished the Hayward Air Rally ( www.hwdairrally.org) for about the 10th time. We placed 8th out of 22, which is about where we usually place. The rally judges us on fuel and time estimates during routes from the Hayward, CA to Redding, then to Bend, OR. We were 1.2 gallons off of our fuel estimate and 37 seconds off our time estimate. The winner was 6 seconds and 0.3 gallons off his estimate, in a 172. This year we tried the "Glass Class", which allows us to us to use all available technology, instead of just a compass, map, and stopwatch. The penalties are tripled and our score ended up similar to our past entries. The winner was in traditional class. Every year the fuel penalty is our nemesis. We know why our time was off, and next year we'll adjust for that. But we can't nail the fuel for any amount of trying, even using the totalizer. There seem to be two issues. First, the totalizer doesn't seem to be as accurate at low ie, idle, power settings. It generally reads 2-3 gph, which we think is high. Second is refilling the tanks to the same level each time. We can't top the tanks or it will vent enough overboard to ruin our score. We use tabs that I installed to fill the tanks to about 28.5 gallons. Even refilling to the same spot on the tab doesn't really return the results we want. We need a system that will show when a tank is refilled to just the same level each time. Any suggestions? The rules allow us to level the plane, which we started doing this year, and we can use a stick so long as it only has a single calibration mark. We haven't used a stick yet. I'm also interested in what others have noticed as far as extreme accuracy of their totalizer. Plenty of folks report sub-gallon accuracy. Anyone doing much better than that? How? Last thing, the rally will be going from Hayward, California to Oshkosh for AirVenture next year. It's a lot of fun, even if somewhat frustrating, and of course a great challenge. If anyone is interested, please look into it. More RVs would be great! Dave Saylor 831-750-0284 CL ________________________________ Message 2 _____________________________________ Time: 08:43:03 PM PST US Subject: RV10-List: Re: Fuel Question From: "woxofswa" It is surprising how much temperature plays a role in the volumetric measurement of fuel. For extreme accuracy, you would need a temperature adjustment formula or graph to fine tune a dipstick measurement. Airliners use dripsticks underneath the wings but the reference tables are graphed by different temperature ranges. -------- Myron Nelson Mesa, AZ Emp completed, QB wings completed, legacy build fuse on gear. Finishing kit and FWF kit in progress. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=403670#403670 ________________________________ Message 3 _____________________________________ Time: 08:45:44 PM PST US Subject: RV10-List: Re: Fuel Question From: "Bob Turner" 37 seconds? That could just be the tower sequencing you #2 instead of #1. How can you plan for that? -------- Bob Turner RV-10 QB Read this topic online here: http://forums.matronics.com/viewtopic.php?p=403671#403671 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message rv10-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/RV10-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/rv10-list Browse Digests http://www.matronics.com/digest/rv10-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.