Originally Posted by MrRoboto
^^So aside from the sound, do you feel any power difference, does it seem to rev more freely?
10whp from the mids, as measured on both my 135i and 1M
2011 BMW E82 1///M: AW, ZPP+ZCV, HK, Apps; Akra CF+Valve control, MadDad mids, K&N, Forge FMIC, P3gauge, EuroTails, Tint, CF Mirrors+Spoiler+Roof+RevoZ diffuser, 10mm H&R, IND grills+gills, xCDV, LUX AE
2008 Audi B7 RS 4: Sprint Blue, Audi Exclusive Euro Interior, Premium+Titanium Package, EPL Tune, Stasis Ohlins MS coilovers, Milltek valved exhaust+DownPipes, Stoptech lines, Tint, ADR V1, Lidatek, Lamin-X, Strasse Forged SM7 3-piece concave wheels, 275/30/19 PSSs, Euro flat-bottom steering wheel, JHM SSK