bmwe21.net forums

The M20 is now in and seemingly running quite well.

I was wondering what people do for the exhuast? I've got an idea of what I want, but I'm not sure it's right.

I was going to do:

Both downpipes into a y-connector, into one pipe, through a backbox and then a single exit.

This sound okay?

I have a full 323i system with some stainless backboxes I got off Rob (Wiz0R). Very secondhand. The idea was that it'd look cool, but when I had to weld some steel into the back end to hold it up, and then cut a hole in the rear valence, followed by the MOT man not liking the way it was supported meaning cutting a bigger hole in the valence, I knew it wasn't! SIngle exit at the back is the way forward, for performance purposes it is also lighter.

Yeah I'm fixed on single exit. Straight cut. I won't be budging on that! haha

Straight cut and shiny chrome is what you need. I keep looking at the Baur and thinking that I need to weld up the hole in the rear valence and get a single outlet. You getting a nice shiny stainless one made? If so I might get one for a group buy!

Track slug has a cobbled together thing so I could do with fixing that as well. So that's 3 cars in the group buy already!

if you go for a e21 6cylinder 320 system. I have a brand new 320 6cylinder 1977 only back box that i would be happy to swap for your used 4 cylinder back box (if it is good useable condition)....1977 is the only year that a 6 cylinder 320 had the exhaust exit by the number plate like your car rather that at the corner of the valance as later cars....

Is that a twin inlet backbox?

on a 6cylinder e21 320 the middle box has two inlets and one outlet to the single back box, i imagine a 323i middle box has two in and two outs with two separate back boxes that exit at the corners of the valance... from the middle box back a 320 6 cylinder system looks similar to a 4 cylinder system but has bigger boxes and larger diameter pipework

Hi, do not use 323i exhaust middle box because of course it come with 2 in and 2 out but after they are very small
look at this : http://www.google.fr/imgres?imgurl=http ... rQMwDTjIAQ

The best way is to do your own exhaust.