M Performance Exhaust

[Black Gold]

Originally Posted by LarThaL

I think 15-20hp is a bit optimistic. There is a power gain, however, I have heard more like 8-9hp. BMW does not advertise this, because that kind of power gain is difficult to consistently replicate on a dyno. My guess is that BMW does want to be hit with any kind of potential legal issues if it doesn't show up on a particular person's dyno pull.

I was talking about the ess kit.

Exhausts Without a tune typically gain 15-20 whp and 10-15 ft lbs.

[anselmw]

Just finished installing mine today, thought it would be quick but took a bit longer due to poor fitment on one of the pipes, had to take a pipe expander to spread the pipe a little to fit, surprised with oem it did not fit perfect. Definitely just getting sound with MPE and no power. There are actually still flat bends to the pipe, not like a full madrel bend aftermarket so i would not expect any power improvement, just that wonderful sound.

[M3 Pilot]

Just out of curiosity, has anyone quantify the benefits of horsepower gains with respect to exhaust ?

I'm not talking about dyno readings. There are ways to "bump up" horsepower figures.

I'm talking about controlled test on 1/4 mile times on both Stock and Aftermarket. Same track, ambient/surface temps, driver, etc.

Reason I ask is because I see a lot of dyno charts but if 1/4 mile times are the same stock mufflers, I don't see how a 100hp gain on dyno translate to any form of benefit.

[FogCityM3]

Cat-back only dynos that have been done on the MPE are +2-5 hp, based on a few done in germany and one done by Eurotuner Magazine. Interestingly on the Eurotuner one, had some modest torque gains on the low end, which isn't the same case for a lot of cat-backs on the M3 (many have losses).

Originally Posted by LarThaL

I think 15-20hp is a bit optimistic. There is a power gain, however, I have heard more like 8-9hp. BMW does not advertise this, because that kind of power gain is difficult to consistently replicate on a dyno. My guess is that BMW does want to be hit with any kind of potential legal issues if it doesn't show up on a particular person's dyno pull.

[pkimM3r]

Originally Posted by CanAutM3

From what I have read so far on this forum is that MPE with an X-pipe does not sound too good, very raspy .

...however, with downpipes

M3's have downpipes?

[CanAutM3]

Originally Posted by pkim1079

M3's have downpipes?

Downpipes (or test pipes) to replace the primary cats...

[pkimM3r]

Originally Posted by CanAutM3

Downpipes (or test pipes) to replace the primary cats...

thanks - didn't know test pipes were called downpipes...thought they were only for turbo cars. a test pipe is just a piece of metal tube that replaces the cats.

[surewin]

Here is the test that was mentioned on this thread. Still tempted to get it :P

[M三]

Originally Posted by Tyranitar

Just the rear section. Robert said that one of the best sounding exhausts systems that he's heard is the M perf exhaust coupled with macht schnell xpipe. I haven't heard it, but if someone has the set-up, they should post it.

+1