manifold trouble

[mark320i]

ive just put a 325i engine in and ive come to connect the manifold up to a 2.0l exhaust sysem but it doesnt fit, by putting the 2.0l manifold on there will this restrict power?

[Ant]

yes mate, you really need to swop to the 2.5 unit and downpipes/system to get the best from the bigger capacity. it will be ok-ish on the 2.0 unit but budget for the bigger as soon as funds allow.

HTH

[jmc330i]

IIRC, there are 2 manifolds for the 2.5.

One has the same size outlet ports and stud spacing as the 2.0 manifold so should bolt up to the 2.0 downpipes.

Looking at the ETK, the pre '87 325i had a different manifold, but the post '87 325i's has the same manifold as the 320i.

[Ant]

Good call !

Forgot the early manifold was tiny on the high comp lumps.

either way, skip it ASAP, restrictive is too small a word

[jmc330i]

Hang on then. My 1991 325i has the larger port manifold, so is this the same as the 320i one then???

I do remember confusion at the BMW dealer when I ordered a manifold/downpipe gasket - everyone that was ordered for a 325i was too small.

[mark320i]

cheers for the help guys, does this mean i have to put a whole new exhaust system? would i not be able to put the 2.5 manifold on then buy that centre section from the zone shop then connect my backbox onto that?

i got quoted 450 pound from my local maike stokes motorsport. (didnt really wana have to resort to them) this was from manifold to back box stainless steel, is this a good price?

im soo confused with this one!

[jmc330i]

would i not be able to put the 2.5 manifold on then buy that centre section from the zone shop then connect my backbox onto that?

I dont know which centre section you mean from the Zone Shop, but in theory, yes. It does depend if you have a 2 or 3 piece system as you cant mix and match the parts - AFAIK, aftermarket exhausts are only normally available in 3 piece.

You could also try Euro Car Parts for a standard centre section.