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Stohlen · 10-20-2012, 12:20 PM

The exhaust system doesnt need to be restrictive to a point on any car. Otherwise you'll actually lose horsepower.

I do believe however that the N54 exhaust is significantly more restrictive than the N55 IIRC.

10-20-2012, 12:20 PM	#5
Stohlen Major 66 Rep 1,267 Posts Drives: AW 135i Join Date: Aug 2012 Location: Waterford, Mi iTrader: (2) Garage List 2008 BMW 135i [5.66]	The exhaust system doesnt need to be restrictive to a point on any car. Otherwise you'll actually lose horsepower. I do believe however that the N54 exhaust is significantly more restrictive than the N55 IIRC.
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