SonexBuilders.net

I am still on the fence to purchase a Sonex-B kit. I like the AeroVee engine option. Love the price. It appears "too good to be true". Specs say 130mph at sea level 150mph at 8500 ft. Will they perform like they say? Is anyone within a few hundred miles of Houston I can come see one?

Engine 62 wrote:I am still on the fence to purchase a Sonex-B kit. I like the AeroVee engine option. Love the price. It appears "too good to be true". Specs say 130mph at sea level 150mph at 8500 ft. Will they perform like they say? Is anyone within a few hundred miles of Houston I can come see one?

Here's a video of me pushing the throttle wide open at 1800ft:
https://www.youtube.com/watch?v=tqVj2IJEbHI

You can see the speed sitting at 120KT initially which is my cruize speed at 3000rpm.

Once I push the throttle forward you can see the IAS slowly creep up and over 140KT, I then pull back again because the EGT alarms are going off (which can also be seen if you look at the MGL E1 instrument (see the second bar from the left start to flicker).

My engine is a VW but it's not an AeroVee though, it more resembles the Hummel 2400cc.
The AeroVee might perform slightly less but I don't think the difference would be huge.
I have a Price P-Tip 54x48 propeller.
My Sonex is an A model but it is my understanding as well that the B model will perform exactly the same.

Engine 62 wrote:I am still on the fence to purchase a Sonex-B kit. I like the AeroVee engine option. Love the price. It appears "too good to be true". Specs say 130mph at sea level 150mph at 8500 ft. Will they perform like they say? Is anyone within a few hundred miles of Houston I can come see one?

You get that a lot when companies are trying to sell kits. Sonex is the real deal though. I flew the factory Waiex and it performed just like they said it would. Judging by the recently posted video of the B Model, it looks like they hit the mark again.

My max speed is a little faster than 140mph, but I expect to see more like 125-130mph at 8500 feet DA. The turbo guys seem to go a bit faster than 150mph at ~8000 feet.

I have a second-hand Prince 54x46 p-tip propeller. It's a great propeller, but I think 54x44 would perform better on my airplane since I am unable to achieve the peak power rpm of ~3400 rpm in level flight (I get ~3250).

Sonex is by far the best performance for the dollar. You can not beat the economy of the Aerovee.

You do have to be comfortable working on engines, however. Even if you are not comfortable working on engines you can learn. I would recommend watching the Aerovee assembly DVD to learn more. If you are not comfortable working on engines you can always opt for one of the other crate engine options. The Jabirus and Camits are good options.

With my Aerovee I am seeing numbers identical to Chris Madsen's numbers.

Jake

From all I have seen the Sonex numbers are real for tail draggers with wheel pants and gear fairing. Sonex says omitting the pants and fairing may cost 10 MPH. Not sure of the speed penalty for tri-gear.

David A. Sonex TD #1327 CAMit 3300 #0004

I believe their website noted a 5 mph decrease in speed with the tri-gear

The top speed numbers are pretty accurate. The only down side to a stock aerovee is the climb rate at gross. The turbo may be better. Solo I can easily see 7 to 900 feet per minute at sea level. At full gross it is closer to 3 to 500 fpm. You have to be careful and be selective in your airports and runways flying at gross on high density altitude days. That being said I flew with my dad from Connecticut to oshkosh last year at gross in the middle of July. I just chose airports with 4000 foot runways and minimal obstructions.

Keith
#554

I can give you my experiences so far:

I looked into a Sonex after air venture 2015 (I was there for the 75th anniversary of the Ercoupe, which I own one of). After that, my interest grew in building but I wasn't sure. I solidified my comitment to building but wouldn't budget the kind of money required, in one shot to order the complete kit from Sonex. Furthermore, I decided that I wanted ALL of the ramp attention, so I decided that a Waiex would be a good fit (I already have one airplane with an unusual tail, and like the attention it garners) so I ordered a tail kit. While building the tail, I decided to look for an unfinished kit knowing it would be somewhat of a needle in a haystack because so few Waiex kits are sold compared to the Sonex. as luck would have it while working on the tail kit, I found a Waiex kit in Texas that was for sale cheap. The tail kit was built but I already had one off those so I wouldn't use it anyway. The flaps and Ailerons were already built but I knew I wanted Sport/Acro so those wouldn't be used either. The kit I bought, W0064, was 9 years old and I would be the fourth owner. The build was meandering along through the winter when Sonex started marketing the "B" models shortly before Sun N Fun this year. I had intended to be there so I thought I would see what it was all about. Sonex had already decided that they would not offer a conversion kit at the point of release but I had hoped they might reconsider. as it turned out, the "NO" turned into a maybe at Sun n Fun when I talked to the good folks in the booth. I told John, Levi and Joe "take my money NOW" they said to be patient and that the probability was pretty good that a conversion kit might be coming. Fast forward 6 months.... I now have 99% of the kit and enough of the drawings to continue moving forward. Being one of the very first "B" model builders, and possibly the first full conversion kit customer, I have found the process largely enjoyable. It has been tempered with a few back ordered parts and delays on some of the drawings but nothing extreme and certainly better than you might expect being on the Bleeding Edge of a new product.

My observation of the "B" Waiex model at Sun N Fun was .....WOW!! more like Ho!!y $h!t WOW!!! The refinements were/are incredible.. It truly is as much of a different airplane as you could imagine, but for the tail and wings.. In my opinion, the existing Sonex/Waiex was 60% of the refinement of a production aircraft, the "B" model is a good 85% refinement level compared to production aircraft of similar capabilities (Please don't flame me, Its just my opinion) Its that good!!


Personal summary:

Between buying the tail kit, uncompleted Waiex kit and the Conversion kit, I have just barely eclipsed the cost of a new "B" model kit. That is acceptable to me because had I paid full retail for the Legacy Waiex kit, that might have been a tough pill to swallow. If I'm honest though, I probably would've upgraded anyway. I am a masochist like that and I never live with regret over what decisions I make, only the ones I didn't make..lol. The B model really motivated me to move forward, and so far, at a faster pace. Working through the growing pains of a new design and the logistics associated with getting parts and drawings is more than worth it to me.. I am a happy Sonex customer and would recommend the company and this community to anyone looking to build. I certainly am a fan of the "B" model

kmacht wrote:The top speed numbers are pretty accurate. The only down side to a stock aerovee is the climb rate at gross. The turbo may be better. Solo I can easily see 7 to 900 feet per minute at sea level. At full gross it is closer to 3 to 500 fpm. You have to be careful and be selective in your airports and runways flying at gross on high density altitude days. That being said I flew with my dad from Connecticut to oshkosh last year at gross in the middle of July. I just chose airports with 4000 foot runways and minimal obstructions.

Keith
#554

Thanks Keith for these numbers. I was curious as well as to what the performance was at gross with an aerovee. I'm assuming climb prop and tail dragger? A tri-gear may perform a bit worse due to the increased undercarriage drag. Someone mentioned that the factory's next plane will be a Sonex with tri-gear and an aerovee (non-turbo) engine. That a/c will be very informative.