Single exhaust system.

[yung-gun]

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?

[327ire]

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.

[StefanAnghel]

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

[f0xy]

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.

[HairyScreech]

That is more or less what the Z3 2.8 had.

Works the same, sounds shite.

[Keiron]

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

[Dannysimmse30]

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

[ACJJ619]

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.