e60 m5's.. no wonder there are so much gain from the headers..

[SANguru]

man.. looking at the factory design on the headers, explains pretty much why it gets such lousy gas mileage and sounds so damn whimpy. Can you say BMW purposely detuning the V10?

http://www.m5board.com/vbulletin/sho...835#post841835

I see headers in my future!

[JV]

Those stock headers looked like they'd been run over by a Mack truck!

JV

[Quicksilver]

Interesting pipework. So your getting the new stuff as shown or something different?

[SANguru]

supersprint is really the only option at this point.

Originally Posted by Quicksilver

Interesting pipework. So your getting the new stuff as shown or something different?

[rayxi]

I don't know a whole lot about exhaust design but the SS headers look like they aren't equal length whereas the OEM ones are. I'm assuming that keeping equal lengths on the tubing before the collector means each cylinder will see the same backpressure, which is good yes?

[vinuneuro]

Josh, what do bimmer guys use to tune?

[SANguru]

dyno? flow bench? no clue..

Originally Posted by vinuneuro

Josh, what do bimmer guys use to tune?

[SANguru]

good question. The concern is the crimping which would really restricts flow. On the a couple of dyno runs, the headers show about a 35hp gain.

Originally Posted by rayxi

I don't know a whole lot about exhaust design but the SS headers look like they aren't equal length whereas the OEM ones are. I'm assuming that keeping equal lengths on the tubing before the collector means each cylinder will see the same backpressure, which is good yes?

[LeMansX5]

You need new headers for your M5.

[rayxi]

Originally Posted by SANguru

good question. The concern is the crimping which would really restricts flow. On the a couple of dyno runs, the headers show about a 35hp gain.

Yeah, I saw the crimping. The degree of crimping didn't seem to be the same on all pipes, which negates the benefit of having equal lengths. wacky. Looks to me like they needed to crimp the pipe to get it to fit between the adjacent pipes. Not a very BMW solution to the geometry problem.