Making a Sonex Faster (Speed)

[daleandee]

Friends, as it now appears under the NPRM us lowly Sport Pilots will be allowed more speed. In that light I'd like to ask the group about what to do to make a Sonex faster.

I'm aware that losing weight (both me & the plane), cleaning up the plane to make it even more slippery than it is, a higher cruise RPM (I currently use ~2900) and perhaps changing my climb prop for a cruise prop are all things that will help. But if anyone has specifics as to the buying or making of fairings, cooling mods they have made, easy weight loss secrets, etc. it would be good if you could share them.

Dan Weseman built a Corvair Sonex and he was recording 135 knots cruise down low but was turning the Corvair at higher RPM. These engines are not hurt by this but the fuel burn can get into the wallet. 8~)

TIA

Dale
3.0 Corvair/Tailwheel

[Scott Todd]

Go watch this YouTube video on why the Ar-5 goes so fast. Its a must watch. Its totally worth the time.

https://www.youtube.com/watch?v=rxvoDbZpoY8

Scott

[Bryan Cotton]

Dale,
Kent Paser's book "Speed With Economy" is a must-read.

[GordonTurner]

Dale….why would a good ‘ole boy wanna go faster?

Gordon

[daleandee]

Dale….why would a good ‘ole boy wanna go faster?

Gordon

Because ... 8~)

[builderflyer]

Friends, as it now appears under the NPRM us lowly Sport Pilots will be allowed more speed. In that light I'd like to ask the group about what to do to make a Sonex faster
TIA
Dale
3.0 Corvair/Tailwheel

Dale and others............Google "Dave Anders RV4". Dave is an ex-airpark neighbor of mine and he flies the fastest (most efficient) RV4 in existance. He's written Kitplanes articles describing what he's done to allow his RV4 to fly over 240 mph and achieve other unbelievable accomplishments. I had the pleasure of flying with Dave a couple of times and can't express in words, what a great ride it was. A number of the things he's done to his plane could be done to ours as well. All it takes to realize some improvement in our planes is for us to exhibit a fraction of the patience and passion that Dave has had for reducing "drag" over the past 30 years.

Art,,,,,,,,,,,,,,,,,,,,Sonex taildragger #95,,,,,,,,,,,,,,,,,,,,,Jabiru 3300 #261

[Bryan Cotton]

I was flying my Aerovee powered Waiex S&L at 140 kts last night.















(For a moment after the dive and before the loop)

[pappas]

I routinely flight-planned my Legacy Waiex model with a 3300 Jab and recommended Sensenich cruise prop for 140 knots at 5.9 GPH. That was the norm for that plane.

[daleandee]

I routinely flight-planned my Legacy Waiex model with a 3300 Jab and recommended Sensenich cruise prop for 140 knots at 5.9 GPH. That was the norm for that plane.

Might I inquire as to which Sensenich prop you had (length & pitch), your cruise RPM, and your cruise altitude? 5.9 is a higher fuel burn than I see but I'm usually loafing along.

I'm have a climb prop now to limit my plane to be light sport legal. If the cruise numbers increase as the NPRM suggest I know I can get a reasonable increase by doing some clean-up on the airframe, losing some weight, and using more of a cruise prop. I know that CG will also effect the speed but that changes as fuel burns off. As it is I can likely get the 140 knots at 8000 but it's been quite a while since I've went up that high to check it ...

[Bryan Cotton]

Here's a question for you guys. At altitude do you turn a higher RPM? At 7500' the other day my IAS was only 90. I didn't check my true airspeed. That was probably high enough that I could run WOT and only make 60HP.