M6 Muffler Mod on 550i +1
Thanks for the pics and details! Your advice came in real handy.
Keeping the muffler forward made all the difference for fitting new exhaust tips. The old 3" M6 tips were way too long for me and turned inward so they were cut off from day one. Shop guy easily fabricated some up slightly up-turning stubs to slide the 3 1/2" X 5" slant angle tips and position them staggered, 1/2 inch from the rear facia .
My guy also fabricated a smooth transition from the M6's 2 1/2 inlet to the 2 3/4 factory exhaust pipe past he axle. Conveniently, he cut past the awful crush that the factory does at this point (for what reason I don't know). So, even though 2 1/2 is less than 2 3/4 pipe, at least the transition is smooth and no crushed pipe.
In summary, the fit up was not too problematic. Muffler fits into space, hangs about 1" lower than stock muffler. The old M6 hangers were cut off and new hangers were fabricated and tied into the factory 550i mounts. The quad pips were positioned at 1/2" protruding from facia and staggered. There was still room to position them shorter or longer but I liked them at 1/2".
Don't have a sound clip yet but just as kthankbz clip shows, it sounds a lot more aggressive at start up. And on WOT acceleration, it is VERY pronounced. At cruise, no drone per-se but a BRRRR sound at highway speed to let you know the engine sound is there.
Overall sound, very different indeed but maybe too loud for me (lol). I'm doing a 600 mile road trip today and will know afterwards if I'm keeping it or going back to stock.
First pic shows muffler not fasten yet but shows the upturned stubs, new pipes slid on, and transition pipe all the way to the factory pipe. 2nd and 3rd quick pics show finished job (poor pics because it just rained today).
Last edited by HDEddie1; 01-26-2013 at 02:35 PM.