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Air Race

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paul330

Well Known Member
In a couple of months I am going to be taking part in Race for Rhinos in Botswana - check out their Facebook page......

This is not Reno - it's basically a handicapped navigation and flying accuracy event - Kings Cup Air-race type. I have not a lot of time on pistons and have some questions. After all, if it doesn't matter who wins, why take times?

- Altitude. I have a NA IO540 on my RV-10. Is it best to stay on the deck to get max power or climb to get better TAS?

- Mixture. I'm going o be WOT all the time. Obviously I can't use the lean mode to try and find peak at those high powers. How do I get best power? Looking at the charts, it appears to be about 21gph.

- Prop. Max RPM for max power? Or 2600 to save the engine a bit. Or lower to get a better "bite" on the air?

- C of G. Do I aim for lightest weight or is it better to load the baggage compartment to get an aft C of G and unload the HS?

If you guys can give me some pointers, I'll have some time to do some trials.
 
Have you searched here for 'SARL race tips" or similar? Lots of ideas/strategies/tips/opinions/fantasy/results posted... Good luck on the race!
 
paul330 said:
In a couple of months I am going to be taking part in Race for Rhinos in Botswana - check out their Facebook page......

This is not Reno - it's basically a handicapped navigation and flying accuracy event - Kings Cup Air-race type. I have not a lot of time on pistons and have some questions. After all, if it doesn't matter who wins, why take times?

- Altitude. I have a NA IO540 on my RV-10. Is it best to stay on the deck to get max power or climb to get better TAS? It depends:D Generally, the incremental HP developed down low overshadows the increased drag. It's somewhat airframe contingent, but a Glassair III and Long EZ both are quite a bit faster when in ground effect, that is, less than half a wingspan AGL

- Mixture. I'm going o be WOT all the time. Obviously I can't use the lean mode to try and find peak at those high powers. How do I get best power? Looking at the charts, it appears to be about 21gph. Lycoming publishes accurate and reliable charts on max power vs CHT& EGT.

- Prop. Max RPM for max power? Or 2600 to save the engine a bit. Or lower to get a better "bite" on the air? Max RPM

- C of G. Do I aim for lightest weight or is it better to load the baggage compartment to get an aft C of G and unload the HS? Both :D Strip it down and get the CG as far aft as possible. I don't know how fuel burn impacts CG on a 10, but be sure to run the numbers both ways.

If you guys can give me some pointers, I'll have some time to do some trials.
Click to expand...

I've flown (and won/2nd) in roughly 40 timed, ~120 mile air races (pre-SARL days). People did things like removing the alternator belt, removed the vacuum pump, removed antennas, taped up all the doors and canopies after the pilot was in, etc. The Glassair was 1-1/2 mph faster with both ailerons reflexed up.

This is a real slippery slope, and you can spend A LOT of time and money chasing speed. Please be careful, and have fun.
 
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