Making a Sonex Faster (Speed)
Posted: Tue Aug 01, 2023 9:07 am
by 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
Re: Making a Sonex Faster (Speed)
Posted: Tue Aug 01, 2023 9:47 am
by 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
Re: Making a Sonex Faster (Speed)
Posted: Tue Aug 01, 2023 9:54 am
by Bryan Cotton
Dale,
Kent Paser’s book “Speed With Economy” is a must-read.
Re: Making a Sonex Faster (Speed)
Posted: Tue Aug 01, 2023 11:55 am
by GordonTurner
Dale….why would a good ‘ole boy wanna go faster?
Gordon
Re: Making a Sonex Faster (Speed)
Posted: Tue Aug 01, 2023 5:55 pm
by daleandee
GordonTurner wrote:Dale….why would a good ‘ole boy wanna go faster?
Gordon
Because … 8~)
Re: Making a Sonex Faster (Speed)
Posted: Wed Aug 02, 2023 9:12 am
by builderflyer
daleandee wrote: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
Re: Making a Sonex Faster (Speed)
Posted: Wed Aug 02, 2023 9:24 am
by 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)
Re: Making a Sonex Faster (Speed)
Posted: Wed Aug 02, 2023 10:06 am
by 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.
Re: Making a Sonex Faster (Speed)
Posted: Wed Aug 02, 2023 5:15 pm
by daleandee
pappas wrote: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 …
Re: Making a Sonex Faster (Speed)
Posted: Wed Aug 02, 2023 5:25 pm
by 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.
Re: Making a Sonex Faster (Speed)
Posted: Wed Aug 02, 2023 8:48 pm
by Zack
Scott Todd wrote: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
Scott, this was a great watch! Thank you for sharing.
Re: Making a Sonex Faster (Speed)
Posted: Tue Jul 02, 2024 1:46 am
by daleandee
builderflyer wrote: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 know it was last year when this was disscussed but the advice here from Art is very good. Here’s the two articles from Kitplanes:
https://www.kitplanes.com/so-youd-like-to-go-faster/
https://www.kitplanes.com/so-youd-like-to-go-faster-2/
Thank you sir!
Dale
3.0 Corvair/Tailwheel
Re: Making a Sonex Faster (Speed)
Posted: Tue Jul 02, 2024 12:14 pm
by Bryan Cotton
Low-wing planes should not be polished due to risk of melting your canopy.
Ha!
Re: Making a Sonex Faster (Speed)
Posted: Tue Jul 02, 2024 9:12 pm
by daleandee
Bryan Cotton wrote:
Low-wing planes should not be polished due to risk of melting your canopy.
Ha!
I read that and wondered what the reasoning was behind that statement. But he also noted that painted planes were faster … ;~)
Dale
3.0 Corvair/Tailwheel
Re: Making a Sonex Faster (Speed)
Posted: Wed Jul 03, 2024 11:57 am
by builderflyer
daleandee wrote:
Bryan Cotton wrote:
Low-wing planes should not be polished due to risk of melting your canopy.
Ha!
I read that and wondered what the reasoning was behind that statement. But he also noted that painted planes were faster … ;~)
Dale
3.0 Corvair/Tailwheel
Are you fellows doubting Dave Ander’s assertion that the sun’s reflection off of a polished airplane is capable of melting a canopy? If so, Dave told me that it happened on more than one occasion. He went on to say that after learning of the potential of a reflection off of his RV4 to melt his canopy or the canopy of an airplane parked adjacent to his airplane, he purposely parked his airplane at an angle to those parked next to him. That worked until someone else thought his airplane needed to be in line with the adjacent airplanes and they moved it in his absence whereupon it soon melted the canopy of the neighboring airplane.
Dave’s RV4 wasn’t just “polished”. If you read the Kitplane’s articles, you’ll recognize that Dave doesn’t do anything halfway. While I never saw his airplane in its polished form, from his description of the care he and his father took in polishing, the finish must have been absolutely mirror like. He would have been satisfied with nothing less.
Art,Sonex taildragger #95,Jabiru 3300 #261
Re: Making a Sonex Faster (Speed)
Posted: Wed Jul 03, 2024 1:37 pm
by daleandee
builderflyer wrote:Are you fellows doubting Dave Ander’s assertion that the sun’s reflection off of a polished airplane is capable of melting a canopy?
Hello Art,
To be honest I’m not doubting what was said just wondering about how that could happen as I’ve owned, and known others that have owned, highly polished planes and this was never a concern. Pardon me for being a skeptic. I did a search (using AI assistant) and found no clear evidence. Of the few references I found most blamed the canopy deformation on the direct sun shining on the canopy of a closed cockpit where the heat inside the plane reached very high temps. There were also references to the tops of panels actually smoking or catching fire because of the refraction of the sun through the canopy.
I was taught to believe nothing I hear and only half of what I see (not as a hard & fast rule but as a guide) and because I’ve never witnessed it I won’t say that it can’t happen but that I have my doubts.
Dale
3.0 Corvair/Tailwheel
Re: Making a Sonex Faster (Speed)
Posted: Wed Jul 03, 2024 3:40 pm
by Bryan Cotton
builderflyer wrote:
Are you fellows doubting Dave Ander’s assertion that the sun’s reflection off of a polished airplane is capable of melting a canopy?Art,Sonex taildragger #95,Jabiru 3300 #261
Art,
I’ve not seen it on the Waiex. I either leave the canopy cracked open (secured with a bungee) or put my canopy cover on. Otherwise it goes thermonuclear from the greenhouse effect.
Re: Making a Sonex Faster (Speed)
Posted: Wed Jul 03, 2024 5:31 pm
by flyguy0609
“Otherwise it goes thermonuclear from the greenhouse effect.” I’m beginning to think that something other than black for the glare shield is a good idea. Actually, for the entire interior.
On the other hand, there is a building in London that reflects the sun and ignites parked cars.
Interestingly the YouTube video says the cross-sectional area of the cooling outlets should be slightly larger than the intakes while the Kit plane articles said his cooling outlets are smaller. The Kit plane guy is using exhaust augmentation, so it’s not apples to oranges.
Re: Making a Sonex Faster (Speed)
Posted: Wed Jul 03, 2024 10:00 pm
by builderflyer
daleandee wrote:
builderflyer wrote:Are you fellows doubting Dave Ander’s assertion that the sun’s reflection off of a polished airplane is capable of melting a canopy?
Hello Art,
To be honest I’m not doubting what was said just wondering about how that could happen
I was taught to believe nothing I hear and only half of what I see (not as a hard & fast rule but as a guide) and because I’ve never witnessed it I won’t say that it can’t happen but that I have my doubts.
Dale
3.0 Corvair/Tailwheel
Hi Dale, I must admit that I’ve never witnessed a canopy being melted either… but then I’ve never caught Dave Anders exaggerating about anything or in particular regarding the spectacular performance of his RV4 and, in fact, its been independently verified. But, anyone going to KOSH, look for Dave’s RV4 (it’s usually parked up front with the race airplanes) and ask him about melted canopies for yourself. His response may make you a believer or perhaps serve to disprove my sanity.
Art,Sonex taildragger #95,Jabiru 3300 #261
Re: Making a Sonex Faster (Speed)
Posted: Thu Jul 04, 2024 9:57 am
by Area 51%
You might want to look up Archimede’s Death Ray.