swiss mufflers

[KayS]

Hi,

i'm thinking about to make/install some swiss mufflers like the ones mentioned in tony bingelis book "firewall forward". it seems that these mufflers could provide the most noise reduction. does somebody have current pics or building tips for that?

(i know that they are heavy, draggy and not the most beautiful accessories, but we have some hard european regulations and the use of ANR-headsets don't help the people on the ground)

thank you
Kay

[KayS]

mmh..ok, really nobody with these?

[rvator51]

I tried them and they reduced the noise level inside the cockpit by 1db at cruise rpm and reduced my speed by 2 knts. Not worth the trouble in my opinion as you cant really hear a 1 db noise reduction. Not sure what it did to the noise level outside the cockpit

[flyboy1963]

Kay, surely JAR? or the other euro regs set a limit for this. Gotta dig out the info from the Brits or some others with RV's........last I recall they had put typical 'aircraft' mufflers under the cowl, where possible.
Perhaps Larry V. has some decibel info on his mufflers? (check out his site)

let us know what you find, I think we'd all like quiet once we heard it!

[islandmonkey]

Never heard of them.

I am waiting to be enlightend.

[Toobuilder]

Originally Posted by KayS

Hi,

...i'm thinking about to make/install some swiss mufflers like the ones mentioned in tony bingelis book "firewall forward"...

I think that you are going to find that the biggest contributor of noise is the prop. If you are "really" concerned about noise, limit the RPM to 2300 or so. Even an unmuffled airplane gets much quieter at really low RPM.