320i twin pipes same size as 325i twins?

[visionz]

as above.. just need to know if they are the same.. thanks

[Quaser]

i dont think they are - but you can fit a full 325i system on a 320 with the right manifold!

[Brianmoooore]

I tried to fit a 320 back box to a 325 front box once.
Lying on the floor, the two rear boxes looked identical, down to the position of the spot welds.
When I tried to fit it, the short piece of pipe that fits inside the other where the two join was about a mm or two too big.

[visionz]

i've got the center box aswell.. so it should just go on..? as the manifolds and front pipes are the same aint they?

[Simon]

i've got the center box aswell.. so it should just go on..? as the manifolds and front pipes are the same aint they?

320i/325i manifolds are the same, so if you have the whole set up from there back, you'll be fine, providing they are the same as in 2/3 piece.

[dannosail]

I've got 2 piece 320 exhaust on 325 manifold - no probs. I think the rest of the exhaust may be different.

As Brian says, and I think some other posts, the diameter of the mid-section and back box pipes are slightly different.

What diameter are the tail pipes? Normally 325 system has 60mm and 320 the smaller 45mm tailpipes coming out of the back box - if they're gen BMW.

[Simon]

Centre sections are identical between 320i/325i, it's the back boxes that are different.

I've got a 325i back box fitted to a system that is originally 320i.

This is all based on standard BMW stuff, problems with fitting always seems to stem from nasty aftermarket mild steel stuff.

[visionz]

cheers lads