325i Sport Exhaust

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massive
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Post Wed Apr 05, 2006 10:19 am

Just a quicky,

Does it matter where you buy a standard 325i sport exhaust from? I remember vaguely there was a discussion on here saying there are some variations but cant find the thread.

I get discount in Kwik Fit but dont want some shite put on there.....but then dont want dealer prices if there is no difference.

thanks in advance
mrLEE30
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Post Wed Apr 05, 2006 10:54 am

depends what you want, full system, half system or silencer.

if only silencer then it will make no difference will only be a looks issue, i.e the angle of the pipes, the size of the pipes etc.

if half system again it will not make any really noticable performance difference.

if full system then it will mainly depend on the headers, BMW designed the headers quite well and if the Kwik fit job is similar in terms of looks and pipe diameter then should be ok, by looks i mean how each pipe bends as they join together into one. Ideal sytem will have equal length pipes from each cylinder with the bend being as little as possible, however design, space and material issues meant BMW made a comprimise so designed their headers to fit into the space allowed, hence why aftermarket headers are expensive, they are also the only real exhaust modification that will affect the performace of your cars engine.

hope that clears up a few points

mrlee
massive
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Post Wed Apr 05, 2006 12:45 pm

Thanks MrLee30,

Its just the centre section blowing. I quite like the look/sound of the standard system so just want to replace not looking to increase performance.

cheers
mrLEE30
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Post Wed Apr 05, 2006 1:52 pm

in that case whack the cheapest one on there that is of the same (or very similar) diameter, the centre section will be of little consequence to performance ( i know your not looking for that) unless you remove the catalytic convertor if you car has one.

put basically the headers dictate the exhaust gas flow rate (and back pressure, scavaging etc etc tech stuff) the middle bit normally has the cat and the silencer does what its name suggests - sliences the noise. Dont be fooled by adverts for aftermarket silencers that promise gains in power, it quite simply does not happen (maybe for those who will comment you will get 1-2hp if the original silencer was extreamly restrictive) so really the silencer dictates the noise levels, personally the sound of the bm 6pot is nice and after market silencers take some of that away!

good luck
massive
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Post Wed Apr 05, 2006 2:06 pm

Great,

Thanks for your time replying
Simon13
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Post Wed Apr 05, 2006 5:31 pm

sport sytem has straight exit tail pipes. normal are angled slightly.

Euro car parts sell these made by boysen for a fraction of the cost from the dealer!
massive
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Post Wed Apr 05, 2006 6:03 pm

Simon13 wrote:sport sytem has straight exit tail pipes. normal are angled slightly.

Euro car parts sell these made by boysen for a fraction of the cost from the dealer!
thanks Simon