Race Engine Forum UK

Hello all,

I'm after advice on an appropriate exhaust system for a Fiat 124 CC running a 2ltr engine.

The engine is relatively standard except for some porting work on the head. I¢ž¢m also running 40 IDF Webers on a waffle manifold.

The exhaust manifold is a standard (Big Bore) 4-2-1 system.

Now the trick is, The car is for daily use, NOT a weekend racer and although I love the Fiat …œRaspy‚ note I do NOT want a loud booming bass note that turns heads every time I go for the Sunday paper.

So what I¢ž¢d like is something that sounds close to standard Fiat sound but offers a better flow for the twin Webers and head work‚¦If it indeed needs to flow better.

I notice the exhaust volume went up considerably when I put the twin Webers on. Is this why Fiat went to 3 mufflers on the 124 BC?

I¢ž¢m going to have the work carried out in stainless steel, so I need to get it right first time.

The standard header pipe outlet is 1-3/4‚ If I went up to a 2‚ system I assume I¢ž¢d have to replace the bottom half of the header pipes as well???

Any comments welcome

Kindest Regards
Gill

Mack, hi

for mufflers you want (I say!) 1 or maybe 2 x George Polley AX891 - flat oval zero back pressure race type. I wouldn't use anything else.

See:

http://www.polleymotorsport.co.uk

GC

Since you noticed an increase in "volume" (noise) after changing to dual carbs, I would guess that the increase in noise is induction noise because of the open foam type air filters you installed on the carbs. That is of course unless you also installed a factory "turtle back" steel air filter housing. This type of air filter housing was stock on the dual carb 124's. They are difficult to find these days but ocassionaly do show up on an internet auction site around 200 pounds though.
Tom McG.