Mizan Posted November 18, 2014 Report Share Posted November 18, 2014 I'm thinking of buying a powerflow exhaust for my 325ci, has anyone got any experience with these on their 325's? The person I spoke to said what they normally do is turn the twin running pipes into one then into the muffler, he said it helps 'free it up' which I am skeptical about. Firstly any extra performance from a back box is I believe a lie and secondly BMW invest millions into their research, I'm sure they would have investigated if it was better to have one running pipe or two and I'm sure they found having two is better which is why there are two exhaust manifolds and no the one. Anyway, does anyone have a powerflow exhaust and how is their's set up? one pipe or two? Thanks. Link to comment Share on other sites More sharing options...
Ruesta Posted November 18, 2014 Report Share Posted November 18, 2014 Don't have one on my BM but did have one built for my Celica GT4 ST185 a few year ago. They did a great job, it was a larger bore and apart from the back box had no silencers - was sooo loud and used to crack and pop all the time. Wouldn't have one like that now but enjoyed it in my youth. After about 1.5 years the back box started to rattle a bit. Drove it back down to them and they replaced it free of charge as part of the lifetime warranty. Even managed to get a slightly larger rear box which sounded and looked better. Would use them again. Link to comment Share on other sites More sharing options...
Mizan Posted November 18, 2014 Author Report Share Posted November 18, 2014 My cousin has a E93 with an autovouge kit and they fit powerflow exhausts, it sounds incredible, I love the crackling and popping on the over run Link to comment Share on other sites More sharing options...
Naj Posted November 18, 2014 Report Share Posted November 18, 2014 I think with Powerflow exhausts it depends on which dealer you go to and who actually fits your exhaust. They are generally custom exhausts built on your car, I've heard amazing sounding ones, and very poor sounding ones - both from two different dealers. (A14 Tyres in Bury St Edmunds vs Elite Direct in Rainham) Link to comment Share on other sites More sharing options...
Ruesta Posted November 18, 2014 Report Share Posted November 18, 2014 I had mine fitted by powerflow them selves down in Bridport, Dorset. I cannot vouch for any of their dealers. Link to comment Share on other sites More sharing options...
Shabaza Posted November 18, 2014 Report Share Posted November 18, 2014 I have a powerflow exhaust fitted to my 8series currently - I took out the resonator and it is veering on the side of too loud. However I no longer use it for commuting so not too fussed Link to comment Share on other sites More sharing options...
Mizan Posted November 18, 2014 Author Report Share Posted November 18, 2014 This is my only car so I'm not looking for something that will do my head in on the motorway. The one on my cousins 335i sounds incredible and the pops and crackles on the over run are addictive, I want an exhaust for that reason lol. Does anybody know regarding the merging the exhaust pipes into 1 before going into the muffler? The guy on the phone said that it makes it slightly cheaper but I would rather pay a bit more and keep it more factory. Link to comment Share on other sites More sharing options...
vmlopes Posted November 18, 2014 Report Share Posted November 18, 2014 Speak to this guy he knows his Powerflow exhausts and very nice bloke to boot. https://www.facebook.com/groups/222715014408572/#_=_ Link to comment Share on other sites More sharing options...
stickboy Posted November 27, 2014 Report Share Posted November 27, 2014 as long as they merge the 2 pipes into a bigger bore pipe say ur 2 pipes are 1"7/8 i think just shy of 2" anyway if they go to 2"1/2 u will be fine as long as the 2 into one part isnt a compleat mess powerflow mostly compression bend there systems same as longlife which means that the pipe is crushed slightly on the bend reducing the overal dia of the pipe hence why i said go for 2"1/2 that way on the bends you will have no less that 2"1/4 dia pipe on the bend as a guide 2" generally will flow 200bhp as long as its mandrel bent Todd1983 1 Link to comment Share on other sites More sharing options...
Mizan Posted November 27, 2014 Author Report Share Posted November 27, 2014 as long as they merge the 2 pipes into a bigger bore pipe say ur 2 pipes are 1"7/8 i think just shy of 2" anyway if they go to 2"1/2 u will be fine as long as the 2 into one part isnt a compleat mess powerflow mostly compression bend there systems same as longlife which means that the pipe is crushed slightly on the bend reducing the overal dia of the pipe hence why i said go for 2"1/2 that way on the bends you will have no less that 2"1/4 dia pipe on the bend as a guide 2" generally will flow 200bhp as long as its mandrel bent That makes sense but what about interfering pressure pulses? I thought that's why they separate the the 2 banks right from the manifold. Or is it not that much of an issue for NA engines Link to comment Share on other sites More sharing options...
E46_CD_Ads Posted November 27, 2014 Report Share Posted November 27, 2014 Slightly off topic but has anyone had an exhaust done for the 320d? Looking for opinions on if it should be done as it will be going for a map soon and it can always help breathing better? Link to comment Share on other sites More sharing options...
Mizan Posted November 27, 2014 Author Report Share Posted November 27, 2014 Are the e46 320d turbo charged? Link to comment Share on other sites More sharing options...
Mizan Posted November 27, 2014 Author Report Share Posted November 27, 2014 I know for turbocharged cars, That if you get turbo back exhaust, it can help the turbo spool up a lot faster reducing lag. But I think if you do ever decide to get an exhaust, you should get it done before any remap as it can only help making the map more suited to your vehicle. Link to comment Share on other sites More sharing options...
E46_CD_Ads Posted November 27, 2014 Report Share Posted November 27, 2014 Yeah turbo diesel, it will be getting the exhaust before the map. Link to comment Share on other sites More sharing options...
stickboy Posted November 27, 2014 Report Share Posted November 27, 2014 (edited) it wont make any diff to the flow if its 2 or one pipe as long as the single pipe is big enough Edited November 27, 2014 by stickboy Link to comment Share on other sites More sharing options...
Todd1983 Posted November 28, 2014 Report Share Posted November 28, 2014 as long as they merge the 2 pipes into a bigger bore pipe say ur 2 pipes are 1"7/8 i think just shy of 2" anyway if they go to 2"1/2 u will be fine as long as the 2 into one part isnt a compleat mess powerflow mostly compression bend there systems same as longlife which means that the pipe is crushed slightly on the bend reducing the overal dia of the pipe hence why i said go for 2"1/2 that way on the bends you will have no less that 2"1/4 dia pipe on the bend as a guide 2" generally will flow 200bhp as long as its mandrel bent That makes sense but what about interfering pressure pulses? I thought that's why they separate the the 2 banks right from the manifold. Or is it not that much of an issue for NA engines Unless your bmw is a v8/v10 it doesnt have separate banks Link to comment Share on other sites More sharing options...
Mizan Posted November 28, 2014 Author Report Share Posted November 28, 2014 as long as they merge the 2 pipes into a bigger bore pipe say ur 2 pipes are 1"7/8 i think just shy of 2" anyway if they go to 2"1/2 u will be fine as long as the 2 into one part isnt a compleat mess powerflow mostly compression bend there systems same as longlife which means that the pipe is crushed slightly on the bend reducing the overal dia of the pipe hence why i said go for 2"1/2 that way on the bends you will have no less that 2"1/4 dia pipe on the bend as a guide 2" generally will flow 200bhp as long as its mandrel bent That makes sense but what about interfering pressure pulses? I thought that's why they separate the the 2 banks right from the manifold. Or is it not that much of an issue for NA engines Unless your bmw is a v8/v10 it doesnt have separate banks Not directly it doesn't, but the front 3 cylinders have a separate manifold for the rear 3 cylinders Link to comment Share on other sites More sharing options...
Todd1983 Posted November 28, 2014 Report Share Posted November 28, 2014 not on the forced induction e46 diesels Link to comment Share on other sites More sharing options...
Mizan Posted November 29, 2014 Author Report Share Posted November 29, 2014 not on the forced induction e46 diesels The NA petrol straight 6's definitely do have separate manifolds for the front and rear cylinders Link to comment Share on other sites More sharing options...
