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I'm interested in putting a straight pipe on my '78/79 e21 320i and was wondering whether anyone had any info regarding how to do this and/or any opinions as to whether this is a good idea. Keeping in mind the engine has had a carbie conversion and no further modification.

Cheers, hanse21.

do you mean striaght exhaust pipe???? as in out the middle of the car?
If so check out murrans car, it requires cutting out the boot floor

if you mean straight through then it will boost your peformance a little but will make it louder

yeah i was thinking more of just removing the muffler and replacing it from there. thanks man

I have a fritz manifold attached to a tiny bit of original front pipe, a cherry bomb centre box then a 2.5" straight pipe on the slug. It hits 103dB on track day noise tests. Probably made a tiny bit of difference power wise, but not been on the dyno properly since I did it.

For the road I wouldn't advise doing it.

Jim

I took the back box off mine and replaced it with twin 3" pipes and my god it sounds good, but my ears will bleed when i have to drive it down to oxford

Mines on an M10 (in the e12), but I've got 2.25" all through with just a little straight through resonator. Sounds awesome but would be a long way from road legal. I love the sound though. Check out the noise on these vids my brother in law took.

http://s926.photobucket.com/albums/ad10 ... 010013.mp4

http://s926.photobucket.com/albums/ad10 ... 010018.mp4

I think it probably made a really small difference right up at the top of the rev range and that is with the Schrick 304 cam too.

Cheers

im in the process of fitting new exhuast to 323 i project panzer

i have found that there are 2 types of middle box, one thats about 60 cm long and one that is about 30 cm long, i have gone for the shorter option.

for the rear pipes im hoping to use yamaha R6 box's, i am getting them 3 off a motorbike nut as there are 2 valves in the zorst that are siezed, these make the bike road legal untill you open up the thottle and the vacum opens them, im either gonna jam them open, or fit an adjuster on there for road legalness and then open on noisy days...... chances are i wont be fooked with wither and will remove the valves completly.

will let people know how it goes

Sorry forgot to add my video too.

This is while the 2 litre carb was still in and was running rough as hell.
Even then i've had a lot of compliments on the way it sounds, you always get a second look in these cars, especially when they sound this good.
I'll add another one eventually when the 2.5i goes in.

nice and loud