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CCCUK » C3 Generation » Exhaust too loud.

#1: Exhaust too loud. Author: MIT Post Posted: Today at

Hi, didnít ever think Iíd say this, but after driving the 74 a few times now, itís just too loud! It really resonates at 13-1800rpm, and not a lot better around that. Now, Iíd rather not fork out for a new system, and wondered if anyone has added custom centre silencers? Itíll also be kinder to the neighbors.
I have ceramic stainless headers, then straight through to a Flowmaster back box on each side, not very big ones at that!
I might go down the soundproofing under the carpet as well later.


#2: Re: Exhaust too loud. Author: roscobbc Location: S W Essex Post Posted: Today at

Your problem may well be the Flowmaster muffler itself. If its one of the 'delta flow' types I think you'll find that it uses a series of deflector plates in the muffler casing to supposedly 'silence' the exhaust with minimal HP losses. There are a number of different versions of these - my experience of them is that they are quite noisy at idle speeds and lower rpm - giving that muscle car sound - when at higher rpm and at load they quieten down a fair bit - but they resonate badly inside the car, especially if A. you have a cam installed and B. and auto transmission with a stock stall speed converter and low numerical axle ratio.
An absobrsion tube muffler (Magnaflow, Jetex, etc) should resonate much less and will be quieter when soft pedalling the gas - and making the right noises when nailing the 'loud' pedal.

Last edited by roscobbc on Wed 11 Jul 18 01:05; edited 1 time in total. [4 %]

#3: Re: Exhaust too loud. Author: MIT Post Posted: Today at

Thatís pretty much exactly it. Low cruising loads itís noisy, and I do have a fancy cam. So maybe a case of new silencers then. Itís a welded system, from the header collector back, so might have to pop into one of these custom exhaust shops. More money!
Cheers Tony. Thumbs up
CCCUK » C3 Generation » Exhaust too loud.

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