sirius206

say you have an 2.5 in x-pipe going into a 2.25 cat back, is there a big power loss or what

Black Horse

its just common sense...the 2.25 cancels out the 2.5</P>

PBR50

It improves the scavenging capability of the exhaust system, as the gases flow from the engine to the end of the tail pipe they cool and contract. If the pipe were the same diameter all the way back the velocity of the gases would slow as they cooled. By dropping the diameter of the pipe the velocity of the exhaust gases stays pretty much constant.</P>


It's engineering 101.</P>


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