Here is a side by side of the a1 headers with stock M5 (540i non-vanos) exhaust manifolds. And a seperate photo of the 540i vanos exhaust manifolds.
Originally Posted by eparayno
Great NA numbers Bricas. Goes to show how huge of a bottleneck the stock headers are. M54 guys dyno'd 15-20ish HP increase with just headers, no cats or high flow cats and the stock exhaust piping on the E46. Would you happen to have a side by side pic of the stockers and A1 headers?
2001 540i - Orient Blue
M5 bumpers, wheels, mirrors
S/C, water/air IC
A1 Headers, Random Technology Cats, Eissenmann Exhaust
3.15 diff, evosport power pullies
Koni Sports, Eibach Springs/Sway Bars
Last edited by bricas45; 07-31-2012 at 01:03 PM.