[Guest]

Basically what the title says, has anyone tested the difference between a stock midpipe and aftermarket, and stock exhaust and aftermarket?

for example:

stock midpipe flows 240fps aftermarket 400

stock exhaust 350fps aftermarket 390

those numbers are just examples, but i'm wondering if one would benefit more from changing out just the midpipe instead of the mufflers. seems you gain more power and the sound of a new catback by swapping out the midpipe alone, not to mention it's cheaper. I've searched for dyno sheets, but can't seem to find any raw test data. also, catback, it it from the stock Y pipe back? or do "cat backs" replace the factory Y/midpipe? seems the word catback is used loosely. the factory pipe between the midpipe with post cats and resonator and the mufflers seens pretty straight forward and doesnt need replacing on an otherwise stock/stage-1/stage-2 car. for serious HP cars i'd run a completely different diamater/setup.

 

[ATL_GT-R]

You are correct in that not much (except annoying drone and volume) is gained by adding a "cat-bacK" on mild build cars -- they really don't make sense from a $/hp perspective. It seems that they become necessary once the turbos are swapped to fully exploit the potential.