AeroVee Performance (Cold Air Induction)

[sonex1374]

I measured the effect of fairings and wheel pants during my Phase I flight test period, and found that the wheel pants were good for about 5 mph, the gear leg fairings for 5 mph, and the intersection fairings that I molded for maybe 1 mph (difficult to accurately measure the change). All told the change between bare and full-fairings was 10-12 mph.

Jeff

[builderflyer]

I measured the effect of fairings and wheel pants during my Phase I flight test period, and found that the wheel pants were good for about 5 mph, the gear leg fairings for 5 mph, and the intersection fairings that I molded for maybe 1 mph (difficult to accurately measure the change). All told the change between bare and full-fairings was 10-12 mph.

Jeff

I agree with the total change of 10-12 mph. However, in my testing I found that the majority of the drag reduction was attributable to the addition of the gear leg fairings and to a lesser amount, the wheel pants. In any event, those who have chosen to fly their Sonex without either of these two additions are significantly sabotaging the performance otherwise gained with their use.

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

[WesRagle]

Hi Guys,

Interesting numbers. I never made the measurements but always found it interesting to read the reports from those who have. The most surprising thing for me was to learn that the drag induced by a round bar hanging out in the air stream was worse than that of a square tube.

BTW, great job on the podcasts Jeff. You missed your calling. You should have been a disk jockey ;-) While I have your ear I want to ask a question. Who is paying for all of this. The web site, the pod casts, etc. Just curious, how does it all get paid for?

[sonex1374]

Wes,

Thanks for the kind words about the podcast. The gang and I have a good time doing them, and we all feel strongly about supporting the Sonex community. We have received assistance from time to time from others, but mainly the show is a labor of love and we bear the costs ourselves. I’d like to encourage everyone to get involved and help share your knowledge and experience. That’s how we collectively get better!

Jeff

[WesRagle]

Wes,

We have received assistance from time to time from others, but mainly the show is a labor of love and we bear the costs ourselves. I’d like to encourage everyone to get involved and help share your knowledge and experience. That’s how we collectively get better!

Jeff

Wow, all I can say is thanks.

I'm a little dense. I just realized that you guys were probably trying to show me that the subject line can be changed while posting. Still getting used to how to use the list.

All the Best,

[lpaaruule]

Hi Wes,

I finally got time to make a short video of my cold air induction, and carb heat. I also show how I did cabin heat. I have tried flying without cold air yet.

https://youtu.be/bvjRLgFCpCI

[WesRagle]

Hi Paul,

Interesting. If you try to compare with/without cold air you might want to cover the hole in the bottom of the cowl. It might kill some of your cylinder cooling if it is left open.

I used oil cooler air without a heat muff for cabin heat and it was adequate down into the 20's. If it was colder than that I just stayed at home :-) It was a "closed system" from the outside to the cabin/dump.

Wes

[WesRagle]

Hi Guys,

Well, I'm working FWF and trying to figure out where everything goes. So ..., it's time to consider "Cold Air Induction". I installed an AeroVee on the Sonex and enjoyed the airplane/engine and had no complaints. However, since I've been there, done that, I'm going try the Hummel 2400cc this time around. The Zenith carburetor comes standard with the Hummel so I decided to give that a try as well. One complicating factor with the Zenith, since it is just an old fashion carburetor, is that carb heat is required.

I had originally intended to install a NACA fed plenum on the cowl side to feed fresh air to both the oil cooler and the carb, similar to what I have done before. After building the box and putting it in place I realized that pluming fresh air and carb heat from there would be difficult. So, it looks like I've made some more scrap.



The only workable solution I have found is to put the airbox/carb heat where the bottom mounted oil cooler would go. Since there will be no oil cooler there, and since oil changes would be much too easy, that's the way I'm going.

While the main air box was disassembled for deburing, I snapped a pic of all the bits in a pile.



Here is a pic of the bottom of the air box.



The bottom with the filter clamped in place.



A couple of views of the "top" of the air box.





A couple of pics of the top and bottom clecoed together and sitting in place.





So, that's where I am on this sub project. Tomorrow I will build the mounting brackets that attach the assembly in the same place the bottom mount oil cooler would be mounted. Carb heat will be drawn up a heat muff on the left front exhaust pipe. I'll measure the temperature rise once the engine is running.

The only logical place to get fresh air is from the front of the cowl. Ram rise!! Should be good for a couple of extra ponies at WOT. I'll take it.

I will have to remove four screws and two hose clamps each time I change the oil. Probably add 5 or 10 minutes to the oil change time. Oh well. We'll see how this all works out.

Forever Forward,

Wes

[Bryan Cotton]

Here is the enclosure for my air filter so far. I'll be adding a 1.75" tube on the bottom for ducting.

air filter cover 1.png (423.15 KiB) Viewed 2756 times

air filter cover 2.png (440.82 KiB) Viewed 2756 times

Edit: the open slot is the top. The fresh air will come in from the other side.

[Bryan Cotton]

Screenshot_20240223-221350-528.png (735.91 KiB) Viewed 2573 times