E30 Zone

Anyone ever experimented with changing from a twin system to a single system of a bigger diameter? How does it effect the engine's performance?

I havent done that conversion myself (apart from on a turbo project) but from what it hear its far from ideal. The bigger bore means the velocity is much slower and makes less power and torque low down. Its a good bit louder to. Turbos prefer a big bore exhaust but on a N/A engine big bore makes more problems than power.

I've got part single (from lambda sensor to the end) and it's very loud... Looking to silence it a bit somehow soon
Don't know about the performance as the m50 is chipped and has a bbtb

I run a single system on an M5x, 2.5" all the way back with two small silencers. This is with M3 manifolds though, which Y into the single system. Can't really say how it affected power in my application, but it flows plenty enough for what I need.

That is more or less what the Z3 2.8 had.

Works the same, sounds shite.

An after market system with x2 1.77" exhausts is the same as having one 2.5" exhaust

I run a single 2.5" stainless system and it runs sweet, just a single back box at the rear too, sounds good, slightly raspy though. Don't know if I'd have stuck with a double system if it would be a deeper sound. But mine still rates like a 6 pot should a˜ˆ

I have a single pipe of 2" diameter. No cat or middle box, literally just like a scaffold pipe to my back box. It's louder than standard but really not that bad at all - and I'm a hater of loud exhausts. Cruising on the motorway it doesn't drone either, so it's ideal. I really like it.

Haven't noticed much performance difference over my old twin pipe setup, although that was blowing in multiple places so it's not a fair comparison. It does feel a little more responsive and nippy but honestly it could well be placebo.