e30 exhaust

Sat Dec 15, 2007 12:20 am

hi, help needed. i have an e30 325i cab 1987 pre face-lift model. my exhaust is a 3 piece system and i am just wondering if i can change the it to 2 piece system? will i have to change the manifold? what will need changing.

help appreciated.
thanks

Sat Dec 15, 2007 12:37 am

Yes, it's a different manifold. Why change? Most poeople would want to go from 2 to 3 piece, not the other way around, as 3 piece has better aftermarket support.

Sat Dec 15, 2007 8:18 am

The manifold IS the same. The systems are fully interchangable.

Sat Dec 15, 2007 9:16 am

The manifold IS the same. The systems are fully interchangable.

The only differnce in this department is if its LHD then the manifold is two piece like the E34.
But as stu says 3 and 2 piece ones are tottaly interchangable.

Sat Dec 15, 2007 12:26 pm

There is a lot of conflicting info on this issue. There is a difference to the number of studs on the manifold. Maybe it's a year related thing, and not a 2/3 piece related issue.
http://www.e30zone.net/modules.php?name ... e+manifold

Sat Dec 15, 2007 1:08 pm

OK, I've done some research.....

320i up to 09/87 and 323i both had the same manifold.
325i up to 09/87 had its own manifold and front pipes.

After 09/87 all M20's had the same manifold, but it was yet another different one.

So it looks like the flange size changed at 09/87.

Does this clear it up???

Sat Dec 15, 2007 5:12 pm

yes that helps thank you very much for everyones help.

Sun Dec 16, 2007 1:02 pm

I'm driving a 323i. Manifold -> centre box (resonator, should be original as it's long) -> Remus backbox.

the problem i'm having now is that my centre box and my piping is giving way due to corrosion and leakage. I've check with the local spare part shop and they do have the OEM centre box for my car but it's cost quite a lot.

I would like to know if it's ok to replace it with 2 hotdog resonator instead of a one piece centre box?

The concern i have in mind is that would it affect the power, fuel consumption and the top speed of my car? as i'm told by some mech that if we pair the wrong exhaust system, it could affect the performance of the car.

Pls advice.

cheers

Sun Dec 16, 2007 1:45 pm

Any badly made/designed/fitted exhaust will have a detrimental effect on the car's performance.
It's said around these parts by guys who should know that genuine BMW exhausts are about as good as it gets.
If you're trying to do it on the cheap, I wouldn't bother. You know what they say.... "buy cheap, buy twice". The pukka stuff lasts for ages - even stainless wouldn't last much longer.

Mon Dec 17, 2007 2:56 am

Ok..thx for the advice..I'm also thinking of getting the genuine BMW exhaust as it comes with the twin piping before the centre box and the piping after the box till the back box.

Guess it's more value for money this way as you can be sure that things won't go wrong with genuine parts. Peace of mind..