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  #11  
Old 09-20-2018, 10:21 AM
FlyFastJP's Avatar
FlyFastJP FlyFastJP is offline
 
Join Date: Dec 2013
Location: Livingston, TX
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Quote:
Originally Posted by Bluelabel View Post
One word of warning in comparing speeds...
After spending the week working as crew chief for Grove aero, race 181...those published speeds are way off... RARA measures the course point to point with the pylons. (This year). They have, in the past, measured ?best flyable track ?.
The planes are actually traveling a much longer distance, but it?s still based on lap times.
So the reality is, everyone is going ALOT faster than what is shown in the results. That?s EVERYONE... I didn?t ask Matt what his TAS was actually showing, but I?m sure it?s much faster...(most people are too busy flying the plane and managing the engine to even bother looking at TAS&#128540.
Just a heads up...
Yes, I heard about that from Axel. Made sense being that published speeds from the last 2 years are lower. I figure Matt and Axel both are running 225-230 mph TAS on any regular day. Those are what I'm shooting for straight and level for my plane. I've talked to Brent Travis as well. His numbers are a bit better than that even. My ultimate goal is to be the fastest RV Blue class (SARL racing) in the south...and with a FP prop. Little gains are hard to come by. I have my work cut out for me for sure.
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  #12  
Old 09-20-2018, 10:27 AM
jrs14855 jrs14855 is offline
 
Join Date: Apr 2008
Location: Lake Havasu City AZ
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Default Dave Anders

Dave Anders has done a series of excellent articles in Kitplanes Magazine about the speed mods to his RV4. The current issue of Kitplanes has his latest article. The engine is a angle valve Lycoming 360 with a lot of mods.
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  #13  
Old 09-20-2018, 10:42 AM
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FlyFastJP FlyFastJP is offline
 
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Quote:
Originally Posted by jrs14855 View Post
Dave Anders has done a series of excellent articles in Kitplanes Magazine about the speed mods to his RV4. The current issue of Kitplanes has his latest article. The engine is a angle valve Lycoming 360 with a lot of mods.
Yes, Dave is the king of the -4. I noticed he's running in the RV Gold sarl class now. That means he's bigger than a 360. I need to look up his old articles relating to the aero work he's done....specifically cooling drag. I'm not going to chase Dave as far as king of the hill goes. He's definitely earned the title. Will be fun to whoop up on the Blue class down here tho.
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  #14  
Old 09-21-2018, 08:39 AM
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hydroguy2 hydroguy2 is offline
 
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I enjoyed SARL racing and the people associated with it. Great fun.
Good luck with your quest for speed. Once you start down that road it is addicting. More power, less drag and technique are the key. You've got some work to do to be competitive, have fun.


I built my plane as sleek as I could, kept it fairly light but still comfy cruiser. It made good power(est. 195hp) for a parallel valve IO-360. BUT I never got good at running the courses consistently to be a top RV Blue racer. Barnes, Rovey, Travis, etc were always 5-10mph or more ahead of me. I kept them honest, but never was a threat to being more than 3rd or 4th place. Best speed on course for me was around 185kts. My plane would run 188-190KTAS straight and level anyday,
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  #15  
Old 09-21-2018, 09:25 AM
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FlyFastJP FlyFastJP is offline
 
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Quote:
Originally Posted by hydroguy2 View Post
I enjoyed SARL racing and the people associated with it. Great fun.
Good luck with your quest for speed. Once you start down that road it is addicting. More power, less drag and technique are the key. You've got some work to do to be competitive, have fun.


I built my plane as sleek as I could, kept it fairly light but still comfy cruiser. It made good power(est. 195hp) for a parallel valve IO-360. BUT I never got good at running the courses consistently to be a top RV Blue racer. Barnes, Rovey, Travis, etc were always 5-10mph or more ahead of me. I kept them honest, but never was a threat to being more than 3rd or 4th place. Best speed on course for me was around 185kts. My plane would run 188-190KTAS straight and level anyday,
Yea, all those guys up NW and NE are pretty fast in the Blue. Luckily, I don't get up there to race so I don't get too humiliated. Lol. The thorn in my side is that dang #118. He's got a clean -8...Lindy winner. He always gets me by 4-5 mph. I'm sure tho that as soon as I get my 1st place plaque, he'll get to work in the hangar.
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  #16  
Old 09-21-2018, 09:48 AM
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skylor skylor is offline
 
Join Date: Aug 2009
Location: Southern California
Posts: 1,046
Default Reno Course Measurement

Quote:
Originally Posted by Bluelabel View Post
One word of warning in comparing speeds...
After spending the week working as crew chief for Grove aero, race 181...those published speeds are way off... RARA measures the course point to point with the pylons. (This year). They have, in the past, measured “best flyable track “.
The planes are actually traveling a much longer distance, but it’s still based on lap times.
So the reality is, everyone is going ALOT faster than what is shown in the results. That’s EVERYONE... I didn’t ask Matt what his TAS was actually showing, but I’m sure it’s much faster...(most people are too busy flying the plane and managing the engine to even bother looking at TAS��).
Just a heads up...
A little bakground on Reno course measurement:

Historically through 2002, RARA used the current course measurement method which is the straight line distance between the pylons. In 2003, RARA switched to the “Optimum Race Path” (ORP) measurement method which calculated the course distance based on the “ideal” flight path around the pylons of the fastest plane in a given class. This lengthened the course measurements and yielded higher calculated speeds for a given lap time. The change was made for purely marketing and promotional purposes. At that time, the fastest unlimited aircraft (Dago Red in particular) were running in the high 400 mph range and they wanted to be able to promote 500 mph speeds to help increase race interest and attendance.

The ORP course measurement method was used from 2003 through 2016. This method created some interesting issues:
1. ORP is not FAI recognized so Reno speeds were not internationally recognized.

2. The course length was calculated for the fastest plane in each class. This resulted in artificially high calculated speeds for slower aircraft and also resulted in different calculated course lengths for different classes on the same course.

3. The calculated course lengths could vary from year to year depending on what the fastest estimated speed for a given class was determined to be for a given year.
For these reasons, RARA decided to go back to the “distance between pylons” measurement method in 2017.

My personal experience in the RV is that the speeds calculated using the former ORP method tended to be artificially slightly high. Sure, we occasionally see bigger true airspeed and ground speed numbers than the official speeds, but the RV’s also lose a lot of speed in turns and on the higher elevation portions of the race course. Also, during the actual races we see some incredible numbers on the first lap when we have a big run from the start chute down into the valley of speed but as soon as we go uphill past home pylon and start the ~ 2g turns of the Medallion course the speeds fall way down!

Skylor
RV-8
Reno #80

Last edited by skylor : 09-21-2018 at 10:16 AM.
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  #17  
Old 09-21-2018, 10:04 AM
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FlyFastJP FlyFastJP is offline
 
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Quote:
Originally Posted by skylor View Post
Also, during the actual races we see some incredible numbers on the first lap when we have a big run from the start chute down into the valley of speed but as soon as we go uphill past home pylon and start the ~ 2g turns of the Medallion course the speeds fall way down!

Skylor
RV-8
Reno #80
I've noticed this exact thing when watching in-flight videos of the planes going around the course. Even taking out the chute, on course speeds vary quite a bit.
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  #18  
Old 09-21-2018, 10:21 AM
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hydroguy2 hydroguy2 is offline
 
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Quote:
Originally Posted by FlyFastJP View Post
....The thorn in my side is that dang #118. He's got a clean -8...Lindy winner. ...
I remember Ken. Beautiful plane. I raced with him in 2012 at the Hill Country 150. Seem to recall I got him that day by a few mph.

SARL used to have a spreadsheet that listed all members and the speeds. you could sort it by class or year or pilot etc. Can't find the link anymore.
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  #19  
Old 02-08-2019, 02:55 AM
Dave Anders Dave Anders is offline
 
Join Date: Feb 2007
Location: cottonwood, calif
Posts: 28
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I know that running in Gold class would normally mean your running a larger engine. I have asked about that but I was told it was because of the modifications that I had done, because I have an angle valve IO-360 running 10 to 1 CR. It's down on hp since my last component changes in the engine a few years ago. Actually I don't think the the airventure cup ever let me run in any other class. The most the engine ever made was around 235 hp but now it is more in the range of 200. It's max FF on the deck is 14.5 gph at WOT 12.6 AFR and running 2800-2850rpm. (I am working on a tuned induction system currently and the first tests seem encouraging) So at 2700 rpm it may be about 190 just for comparisons. During the airventurecup race it ran 1 CHT at 340 and the other 3 around 330 and i think the OAT was in th 80s and that was at about 1700 MSL. With my inlets, plenum and augmented exhaust, it's over cooled. However, it does allows my to climb from my 600' rwy to 17500' in about 10 mins at 110 IAS under max power conditions in the summer here in Calif. I see 1 cylinder at 380 and the other 3 don't break 370 and that's as I go through about 12000' then it start cooling down. The oil temp will make about 218 under those conditions but it also starts dropping at around 12000'. All in all i wish i had on made the inlets a bit smaller and followed my original calculations in 1995 but since I'm not an aero engineer, I oversized them 10% by volume and they're too large. I run a 75-78% outlet to inlet ratio and have a total of 34 sq ins of inlet. I would like to see about 410 CHTs or so in a race. I think the plane would be a bit faster. But it runs pretty good now and that would be a LOT of work to change my carbon fiber cowl. BTW, my rv with an angle valve IO-360 and a hartnell constant speed prop weighs in at about 1010 lbs (empty weight) with all the weight management I've tried to do. I was able to get the weight down to 975 lbs for the triaviathon competition with the battery, starter still on the plane and day VFR legal. That was according to the CAFE foundation.
Cheers guys,
Dave
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  #20  
Old 02-08-2019, 04:29 AM
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Dan 57 Dan 57 is offline
 
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Location: LSZF
Posts: 963
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detailed and very interesting answer Dave, thanks!

Having raced a couple of times here in Europe (Italy), we had GPS loggers installed prior to the race, giving exact speeds and rankings afterwards. Is Reno still in the Stone Age?
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