Fastback

Has anyone been able to quantify performance difference in RV4 fastback vs stock?

Headroom and esthetics (opinion) seem to be obvious advantages.

Byan

IAS, TAS, and ***

Well, I would expect a gain of about 5KIAS, and maybe a bit more in TAS - 6-7kt at higher altitudes...but the MOST IMPORTANT is 'Apparent Airspeed' (which probably would not pass the VAF filter if typed in here).

I suspect that you will gain close to 15KAAS. That makes the process worth the effort.

Keep in mind that this mod also stiffens the aft fuselage a bit.

Carry on!
Mark

I have a fastback with a fresh 160hp 0-320 and we are still under Vans advertised performance numbers. It could be the prop, but I'm not seeing the extra speed gain. I just think the fastback looks better.