Originally Posted by jagman
Great documentation! I recently got an 08 E92 M3 that came with the Akra slip-on. I've contemplated the Akra midpipe but the Akrapovic midpipe would have smog implications in CA. The Challenge Street X-Pipe was recommended since the primary cat stays in place. I see from you that requires welding. I was hoping to do the install myself... that might not be possible. How is the drone now that you have had it a while? Also, have you considered the ESS tune with the cold start mod for that drone?
Thoughts from anybody for that matter?
It is not required to be welded at all actually even though some may choose to do so. Stainless clamps are provided with the street x pipe so that it can be installed by anyone and also removed later on if going back to stock.