I've found someone who is willing to make me a stainless steel exhaust manifold for my Indy Zetec, to my design. But now I'm looking for the tube diameters I should be aiming for. The manifold will be a 4-2-1 design.

Any suggestions? Or site where I could find out what to use?!

Any help is appreciated.

Marcel

Marcel,

have a look here:

www.headerdesign.com

Or, as a starting point, have a look at the flange (you've already got one, don't you?) what the diameters are on a stock manifold. Increase the cross-section by 20% and you won't be that far off. For the two and one (just before the can) section, i'd make sure the total cross section of the pipes stays the same, to avoid sudden changes in exhaust gas velocity. (so the single pipe would be twice the diameter as the primaries, end the secondairies would be 1.41 times the diameter of the primaries.

Or you could do with whatever sizes you can get your hands on.... If you've got trouble locating tubing, maybe you could try bos exhaust systems in steenbergen (NL). Do a quick google to find them.

Cheers,
Sebastiaan

We make manifolds/systems for any engine car/plane/boat/bike!

Rover v8 chevy zetec Duratec This is our new project for Westfield.see pic. ( 260 bhp)

Equal length headers

http//:www.shinybitz.co.uk

TEL 07720713885
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Looks sexy! But I'm afraid you'd need my car to make a manifold (because there are so many parts obstructing the available space: engine mount, steering shaft, chassis tubes).

Since I'm in Holland, that's a bit of an issue....

Crikey, that duratec must be revving some, they are seriously short primaries for a 4-1 manifold!

The spec was 26" and that's what they are. Tyr a different angle see below


[Edited on 11/4/05 by rocket]

different angle ( they did change it to 30" After I'd done all this work!
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