nutter 1 Report post Posted June 12, 2009 Hey there I think A lot of people would have asked these questions but oh well I have a NZ new 1991 e34 525i Manual with the M50B25 motor I was looking at Building a custom exhaust From what i can see there are no sensors after the or befor the cats(Not sure if theres one on the manifold) and i was wondering does any one have any Headers( Extractor)for my car What would be the best size Tubing to uses for the exhaust 2x 2.5" from headers throw highflow cats to Muffler Or 2-1 3" through a high flow cat to a muffler Does my car need the Cat,What would happen if i removed it Or does any one have a Free flow exhaust that would give my car a bit more power ? Thanks Nutter Quote Share this post Link to post Share on other sites
320guy 0 Report post Posted June 12, 2009 You could try the m52 manifolds, they arent proper extractors or anything, but probally an upgrade from the cast iron manifolds that you have. Ditching the cat wont hurt anything except for the enviroment, but who cares anyway. Quote Share this post Link to post Share on other sites
kiwi535 538 Report post Posted June 12, 2009 A NZ new 1991 car wouldnt have had a cat .....Exhaust mod on its own prolly wont give you any performance increase,but you may save some weight ,and have some potential if you increase the breathing of the engine. Cats wouldnt have been available until leaded petrol was phased out which was 1996 Quote Share this post Link to post Share on other sites
BM WORLD 1264 Report post Posted June 12, 2009 i have these from a e39 528i . Quote Share this post Link to post Share on other sites
nutter 1 Report post Posted June 12, 2009 i have these from a e39 528i . hey there will they Bolt on ? and how much where you wanting? Quote Share this post Link to post Share on other sites
BM WORLD 1264 Report post Posted June 12, 2009 hey there will they Bolt on ? and how much where you wanting?$200they will bolt up to the head , but you will have to sort out bottomend of them to fit to a e34 exhaust system also have front exhaust system that bolts up to these but not sure if any use in a e34 Quote Share this post Link to post Share on other sites
nutter 1 Report post Posted June 13, 2009 Hey there when you say 'primary ID,secondary ID" what areyou meaning sorry really new to doing After market modes when you say '35 mm " are you meaning the tubing thickness used to make the headers? are they REALLY hard to make or is it just a simple all tubes need to be equal and no sharp turns so its got a balenced FLOW ?and maybe is there some one that could help me make the headers and exhaust or make them for me at a Cheapish Price lOL The Exhuast After the headers i can Weld up and make as i have done it a few times for my NISSAN DRIFTERS(cefiros) lol i just need some one that know what they are on about with the Headers to help or to pay to do it Thanks Gareth Quote Share this post Link to post Share on other sites
kerrynzl 3 Report post Posted June 14, 2009 Ring STA (09) 2561120 They had some LHD headers in stock [ going cheap but need a cut'n'shut ] or they can get the correct fit for you Quote Share this post Link to post Share on other sites
smiddy 76 Report post Posted June 14, 2009 I think my M52 shorties will go on there Kerry! Quote Share this post Link to post Share on other sites
