Compact Silencers - Whats best?

[dan_t]

Hi all, looking for some advice if I can please!

I've got an '85 Corvette thats running headers, and a full stainless system. I love the sound but its just too loud.

I've got room up the from for a pair of bullet cats like this sort of design http://www.pipercams.co.uk/exhaustshop/images/Pipe... but I'd struggle to get anything much bigger than this in.

Are these cats the best answer or is there a better way of silencing? I'm not to worried about sacraficing some power.

[bales]

You want to put cats on a car that doesn't have cats?

Does your exhaust have no boxes at all?

There must be room for some boxes surely, just get some universal long smaller diameter ones if ground clearance is an issue....

Either I'm being a bit dim or you haven't explained it very well

[dan_t]

There are 3 boxes in total. A large central resonator and 2 silencers on the rear. The only other place is free is between the headers and the catback.

[bales]

Can you not get some better existing silencers, 3 boxes should be more than enough to keep it relatively quiet, I would guess you boxes don't have much in them and are just resonated rather than glass packed.

I have seen single seater hillclimb cars with ex F1 engines in with two large silencers and the keep them amazingly quiet considering!

Have you looked at people like Simpson race exhausts or BTB, I am pretty sure they could knock you up some silencers that more than do the job....not cheap though.

Personally I would do that before whacking additional boxes in, especially cats which will sap performance.

Edited by bales on Wednesday 14th April 11:48

[Shelsleyf2]

I had a problem with noise on a race car, did some research and went to see a couple of silencer manufacturers...re how the silencer works and the effects of design.The way it was explained to me the typical silencer is a perferated tube inside another tube with the space inbetween packed with sound absorbent material, so the bigger the distance the sound waves travel through the sound absorber the greater the silencers effect. So bigger dia and longer will, all other thiungs being equal give greater silencing. The material used for the outer tube and the material used for the packing will also have influence. I was told mild steel deadens sound more than stainless and the old fashioned twin wall mild steel design was a very good design and material. The sound absorber needs to be packed to the right density..too much and the sound passes straight through...too little and the sound is not absorbed. I was told one of the best materials is single filament basalt rockwool. Its a continous strand..it has to be wound on the tube and then cut, it resists being broken down and blown out the back of the exhaust longer than the random length packing.

Just what I was told...I had space issues and decided I could live with the noise.

[dan_t]

Not the best video's as I'm always with another loud car... we both have the same exhaust systems but he's running cats which take the edge of it slighty.

I'm the Blue/White one...

http://www.youtube.com/watch?v=Eu05L2AL8QA