another happy oem exhaust modder
so i just got my modded stock exhaust installed and wow -- online videos really don't do the results justice...for me -- a guy in his mid-thirties with a wife and kids -- this mod seems to be the perfect balance between an enhanced/more aggressive sound and over-the-top loudness...in fact, from inside the car in most driving situations, i really can't tell a difference between modded and stock...but when you get on the throttle a bit the sound really comes alive...oh, and the ride from piper to my office was about 20 minutes on the toll road -> beltway cruising between 65mph - 80mph and i noticed no drone what so ever...
huge shout out to robbie and the guys at piper motorsports for a top notch job...special thanks as well to tuner1984 for the donor exhaust...and last but certainly not least, props to periokid for the initial idea...obviously this mod has been discussed ad-nauseum on this forum, but just in case anyone is curious, the basic steps we/piper took were;
1) cut open the top of the can
2) remove the sound deadening material
3) cut and remove the two larger perforated tubes (the smaller perforated tubes that are covered with the steel wool-like material were untouched)
4) fabricate and weld in two non-perforated exhaust tubes in place of the old perforated ones
5) stuff the sound deadening material back in
6) spot weld the two layers of the muffler together (this was done to ensure no rattling over time...note that this would only be necessary on early e9x exhausts as i believe bmw switched to single-layer cans in either 2010 or 2011)
7) weld the top of the can back on
8) paint the can with flat black silicone-based paint
below are a couple pics of the finished product (bottom, top, then a close up of the top to see the welds)...i'll post more pics of the work in progress a little later on...
2011 (e90) m3 <- 2009 (e90) m3 <- 2010 (b8) s4 <- 1997 (e36) m3 sedan <- 2006 (987) cayman s <- 2005 (e46) m3 <- 2003 (986) boxster s <- 2001 (e46) 330ci...all sold
Last edited by abugiacomo; 12-02-2011 at 01:37 PM.