Originally Posted by bdaddylo
Stock rear sucks compared to any aftermarket no matter what midpipes you're running. I believe the stock rear is more restrictive than the stock midpipes.
Not from my experience. The midpipes (MadDad) on both the 135i I had prior, and the 1///M added a lot more power (10whp/8wtq), than the rear cans (MadDad in the 135i case, Akra Valves open in the 1///M case, both of which were between 2-4rwhp, in fact the manufacturers state that).
The stock midpipes are definitely more of a bottleneck than the rear can, relatively speaking.
PS: perhaps that also explains why the N55 engine is rated at the same HP as the N54 as the loss of one turbo is partially offset by a frier flowing midpipe.
2011 BMW E82 1///M: AW, ZPP, ZCV, HK, Sirius, Apps; Akra CF+Valve control, MadDad mids, K&N, Forge FMIC, P3gauge, EuroTails, Tint, CF Mirrors+Spoiler+Roof Wrap, 10mm H&Rs, IND grills+gills, xCDV, LUX AE
2008 Audi B7 RS 4: Sprint Blue, Exclusive Euro Recaro Interior, Premium+Titanium Package, EPL Tune, Stasis Ohlins MS coilovers, Milltek valved exhaust+DownPipes, Stoptech SS lines, Tint, ADR V1, Lidatek, Lamin-X, Rotiform SNA 19x10" wheels, 275/30/19 PSSs, Euro flat-bottom steering wheel, JHM SSK