23-03-2013, 12:42 PM
Yeah, bigger the pipe, the boomier it is...
You'd be surprised how big 2.5 or 2.75" actually is... The main point isn't so much exhaust size, it's all to do with the silencing in it and making it unrestrictive.
And to be perfectly honest, there's MUCH bigger problems than the exhaust pipe that I'd be sorting long before going for a 3" system, for example the stock exhauts elbow may as well be thrown in the bin, it has NO place on an engine running double the power and in my honest opinion, the stock HDi exhaust manifold is a bag of wank also, just improving it slightly would help things massively.
Especially when bigger turbos are on the cards, keeping everything small at 90hp to keep gas velocity up and make sure the turbo spools early, but having that same item at 200hp isa recipe for massive restriction, high exhaust manifold pressures, lots of heat in the head and not liking anything above 2800rpm!
![[Image: %24(KGrHqNHJCkFBkpTmhiJBQmV(13PEQ~~60_12.JPG]](http://i.ebayimg.com/t/PEUGEOT-307-01-08-HDI-2-0L-TURBO-EXHAUST-MANIFOLD-/00/s/NjgzWDEwMjQ=/%24(KGrHqNHJCkFBkpTmhiJBQmV(13PEQ~~60_12.JPG)
I mean... Can you see that moving anything like 200hps worth of air...
You'd be surprised how big 2.5 or 2.75" actually is... The main point isn't so much exhaust size, it's all to do with the silencing in it and making it unrestrictive.
And to be perfectly honest, there's MUCH bigger problems than the exhaust pipe that I'd be sorting long before going for a 3" system, for example the stock exhauts elbow may as well be thrown in the bin, it has NO place on an engine running double the power and in my honest opinion, the stock HDi exhaust manifold is a bag of wank also, just improving it slightly would help things massively.
Especially when bigger turbos are on the cards, keeping everything small at 90hp to keep gas velocity up and make sure the turbo spools early, but having that same item at 200hp isa recipe for massive restriction, high exhaust manifold pressures, lots of heat in the head and not liking anything above 2800rpm!
I mean... Can you see that moving anything like 200hps worth of air...
