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-   -   mufflers on rv (http://www.vansairforce.com/community/showthread.php?t=153261)

skidookid 09-12-2017 07:30 AM

mufflers on rv
 
RV 8 with 0320 vetterman exhaust and catto prop seems very noisey in cockpit. has anybody installed mufflers on rv after flying with straight exhaust and what results. I use noise cancellation headsets that do help.

Raymo 09-12-2017 08:31 AM

Vetterman offers mufflers for some exhausts. I am running the Trombone exhaust with straight pipes and Bose A20s. Noise is not bad at all but I have FlightLine interior's padding and carpet on the floor, which helps.

bruceh 09-12-2017 12:53 PM

I went with the mufflers for my IO-320. It is still loud, so if I were to do it over, I would skip them. Less weight. Easier installation. More space against the lower cowl. Less scat tubing. Less heat under the cowl (the mufflers need cooling air).

Best solution for noise is a good active headset.

dtw_rv6 09-12-2017 12:58 PM

I've heard that cutting the exhaust tips at a 45 to the discharge path will let the sound resonate away from the fuselage, thereby reducing cockpit noise. I have not done this so I can't comment on how effective it really is.

Don

Toobuilder 09-12-2017 01:55 PM

Quote:

Originally Posted by dtw_rv6 (Post 1203524)
I've heard that cutting the exhaust tips at a 45 to the discharge path will let the sound resonate away from the fuselage, thereby reducing cockpit noise. I have not done this so I can't comment on how effective it really is.

Don

A downturn really helps. I built a 4-1 for an airplane which originally had a muffler right at the collector - it was still loud. Ultimately the muffler was replaced with a slash cut downturned tip and that was more effective at cockpit sound reduction (and a LOT lighter).


Dbro172 09-12-2017 09:01 PM

Quote:

Originally Posted by bruceh (Post 1203519)
I went with the mufflers for my IO-320. It is still loud, so if I were to do it over, I would skip them. Less weight. Easier installation. More space against the lower cowl. Less scat tubing. Less heat under the cowl (the mufflers need cooling air).

Best solution for noise is a good active headset.

Same here, agree with this. Might actually try a set of Vetterman crossovers without mufflers. Although I do like the cabin heat up here in the tundra, coming off the mufflers. Can fly in a T-shirt down in the 20's.

RV6_flyer 09-12-2017 10:03 PM

Quote:

Originally Posted by Toobuilder (Post 1203537)
A downturn really helps. I built a 4-1 for an airplane which originally had a muffler right at the collector - it was still loud. Ultimately the muffler was replaced with a slash cut downturned tip and that was more effective at cockpit sound reduction (and a LOT lighter).


I purchased my exhaust from Vetterman and asked to purchase the "optional turn downs" and was told they would fabricate the exhaust for me with them already built in. I said ok and asked how much extra? Was told they would include them in the price quoted.

Yes the 22-1/2 degree turn downs makes a big difference in the amount of vibration one feels on the floor and the noise in the cockpit.

krw5927 09-14-2017 10:47 AM

Quote:

Originally Posted by Dbro172 (Post 1203655)
Although I do like the cabin heat up here in the tundra, coming off the mufflers. Can fly in a T-shirt down in the 20's.

Definitely appreciate this about my Vetterman mufflers. In the winter, anyways. Perhaps it's time to call Vetterman and get a set of lower pipes without mufflers to swap to during summer when the cabin heat isn't needed. Then it would be possible to block off the hole in the baffles that otherwise wastes potential cylinder cooling air.

rjcthree 10-19-2017 08:05 PM

Can the standard pipes be cut?
 
Can the standard Vetterman pipes be cut at an angle close to parallel to the fuse floor to come close to the turn down effect? I'd rather not add weight or parts. Does anyone have experience with this?

edsong 10-19-2017 11:03 PM

Mufflers
 
I wish they would quit calling our heat exchangers mufflers. They do nothing to (muffle) the exhaust noise.

Eddy


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