Exhaust for S38

[Sharino]

I am making an exhaust for my S38 powered E30. It will be complete custom from the S38 headers back. I need to order some stainless materials and wanted to get some advice.

The 2 header pipes are approx 1 7/8" think each at the joints. I would much prefer to do a single pipe of say 3" back but do you think I will regret it. Would a dual 2" be much advantage?

Any advice on recommended sizes appreciated as well as muffler ideas.

[nando]

why would you regret single 3"?

I wouldn't do anything smaller, personally. dual 2" is just going to weigh and cost more. get a merge collector for the headers to single pipe, high flow metal core cat, and a couple mufflers of your choice.

[Sharino]

I just assumed you get better results with dual pipes as that was BMWs original design. I am by no means an exhaust expert. Think 3" will be sufficient?

[nando]

dual pipes is mostly a looks/ground clearance thing, but GC isn't a big issue with 3". The old M3 DTM cars used like 4-4.5" exhausts.. lol

yes, 3" is definitely enough :D

[FredK]

The DTM cars also ovalized the tubing right under the subframe. :razz:

However, you won't have a problem with ground clearance, a 3.0" exhaust, and a reasonably low ride height.