Bushmaster exhaust pipe

[Alfredo]

The picture shown in the latest Bushmaster delivered shows that it has a device to drag clean the exhaust pipe. Does anyone know how many more knots I will get in my plane if I install one of those? My bird do not have one.

[Pete of N978PB]

Alfredo,

Probably the person with the best understanding of the increased speed from the exhaust fairing is Todd Peterson.

He (and many others) is presently at the AOPA Expo in Palm Springs, and so it may be a few days before he can respond to your query.

Regards,

Pete

[kwmoore]

At the AOPA Expo Todd remarked more than once that the exhaust fairing was more for appearance than for any speed gain.

As evidence to support his assessment, I cite Glen's 2099X, the fastest 260se in the alpha quadrant, which doesn't have an exhaust fairing.

[n2099x]

I have the Horton mod that covers the gap between the exhaust pipe and cowl. The speed increase from it would be a drag reduction from less air blasting out of the cowl. After I’m finished testing the Vortelator tape I have a 90degree piece of exhaust tubing. I want to turn the exhaust aft without extending the overall length any more than necessary to reduce exhaust staining. Some products claim a speed by turning the exhaust into propulsion instead of drag. Time will tell.

Glen

[LEVON HOPKINS]

GLENN, I 've always been insterested in a "quieter cockpit" since I have lost all the hearing I can afford to lose. Having had, as my first plane 1957 182 in the mid 70's then an executive Mooney then a 201 and finally today 1980 Q Model 182 N5384N. During the time I was trying anything to quiet down the mooney planes, I met and talked with the late great Roy Lopresti about a rumor that he had tried to get a "little more speed" and "quiet" out of the 201 by running the exhaust pipe all the way to the rear of the plane hoping the power pulse would overcome the drag....it did not and in fact he said "it cost 2 or 3 knots; but it 'sure did quiet the cockpit!" I tried to get the same installation on my 201 but everybody that had anything to do with it was dead or gone.
Recently talked with an aircraft exhaust mfg. that claimed that any pipe longer than it has to be would crack open quickly. I'm Interested in quiet first speed second.

[n2099x]

Levon, I did make my exhaust extension it turns back almost 90 degrees. I made it so it would slip into my current oval exhaust. Then I started shortening the length of the stock exhaust pipe until I started getting some minor exhaust staining after about 100 hours of use. It is slightly longer than stock and is a snug fit with one screw as security. It has now been in use for about 400 hours, and I can’t remember if it is quieter or not I made it to reduce exhaust staining without losing speed and hoping to gain some. Any speed gain was so small you couldn’t notice it but I don’t think I lost anything. I have reinsulated my entire plane with Soundcoat insulation, and I don't think it’s as loud as it was, but the Bose headsets have done the most to quiet things down. I will post a picture when remember the camera.

By the way your strip sounds great.

Glen

[LEVON HOPKINS]

Thanks; but, it isn't. Went out to Colorado. Tried to learn how to land on some straight, flat, 2mile runways etc. Did not make a single good landing out of 9 tries. Oh, we didn't break anything; but, no really smooth landings until I got home and went up with my partner son and made a really fine silent landing at home. It is wonderful to have my own strip after 30 plus years and I'm grateful for it. As soon as we can, we will try to get looking like a real runway instead of a "run a way" strip.