Vetterman Exhaust

[rv8ch]

Just a quick comment on my RV-8 Vetterman exhaust. I had to remove it to install my new silencers, and I am really impressed with the design and build quality of this exhaust system. Everything comes apart and goes together so perfectly. It's a delight to see such attention to detail. I sure hope they keep up the great work!

[YvesCH]

Hi Mike,

can you explain what you mean with silencers? Did you install additional ones?
I have a Vetterman Trombone exhaust with two silencers.. I hope to be "silent" enough to pass at least the Class D requirement as I have a fixed pitch prop and maybe it will not rev at full rpm at the low altitude where the test will be performed...

Cheers Yves

To all others: Yes in Switzerland we are bothered with these things..

[rv8ch]

Originally Posted by YvesCH

can you explain what you mean with silencers? Did you install additional ones? ....

I bought a pair of silencers from a company in Germany. The silencers didn't come from Vetterman, but I removed the Vetterman exhaust to install them.

Happy to send you the details of the silencer supplier if you like, but you have to be patient. Took him 24 months to deliver, but they were inexpensive, and are very nice.

When I do my noise test, I hope I can do it both with and without in order to quantify the noise reduction. Will take 5 mins to remove/reinstall them.

[JoopSJ]

Hi Mickey,

Could you post a link to the supplier?
Are you installing the silencers voluntarily?
I assume that you don?t need the noise certificate since the RV8 falls in the aerobatic category (ICAO rule).
I will voluntarily install install the silencer on my 7 if the gain is substancial.
Very interested in the noise results with an without.
Cheers Joop.

[Lufthans]

I'm back in the RV game again. Bought a rather derelict looking RV-3 that will be my starting point for a fun project. It does have a Vetterman though, which when we were there to inspect the aircraft was incredibly loud. Much louder than the one on the -4 that I co-owned.

We're in a rather noise sensitive area here as well, so just like Joop I might actually silence myself as well, voluntarily.

So Mickey, curious as well....

Hans

[rv8ch]

PMs sent with the supplier contact information to not run afoul of Doug's rules.

I installed the silencers to try to be a good citizen, reduce the landing fees at airports that charge based on your noise certificate level, and just for the heck of it.

[Lufthans]

Thanks Mickey!

Do you happen to have pics of the exhausts? I didn't see them on your blog?

(And have you flown your 8 yet, by the way?)

[keitht]

Just as an aside. The Yorkshire Gliding Club in the UK operated two Pawnees with O-540 engines as towplanes. Both had the four bladed hoffman composite fixed pitch propeller fitted to deal with the noise requirement at their hilltop airfield. One had a muffler kit and the other had straight pipes. On the ground there was a noticeable difference in the noise signature. The one with the mufflers could be described as sounding like an energetic sewing machine. The lack of audible warning that the prop was turning was a potential risk factor for a serious accident for the unwary during ground operations. In the air during towing operations both sounded very similar drawing the conclusion that a lot of the noise at high rpm settings comes from the prop. The four blade hoffman propeller is considerably quieter than the two bladed prop and has considerable shorter blades thereby reducing the tip velocity at high power setting. It also comes with a significant reduction in thrust compared to the two bladed prop. I hope the addition of mufflers is sufficient to meet your noise signature requirement.

KT