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      03-14-2013, 10:02 AM   #3
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Andrew@ActiveAutowerke's Avatar

Drives: 17 F80 M3 YASSS
Join Date: Dec 2011
Location: Miami Fl

iTrader: (5)

Originally Posted by M3takesNYC View Post
I have an active xpipe/HFC with 2 resonators and my oem xpipe off the car and was comparing them. The AA has smaller diameter piping throughout the entire way. I didn't have a tape measure but used a string and marker. Need to find a ruler or measure but it appears the AA is 2.25inch piping and the OEM maybe 2.5 inch piping.

I am wondering if this is engineered to increase velocity or was it simply a matter of that small of a difference does not matter and 2.5 inch is much easier to get than the wier d2.75 inch bmw likes to use in other applications?

Our X-pipe is 2.5 inches measure from the outside of the pipe. The inside measurement is 2.3 inch.

We made a custom 3 inch x-pipe for a customers race car per his request and lost power. Bigger is not always better...