what is the most power efficient and loudest exhaust pipes sizes.... i want mean and low sounding.... but lots of power. i was thinking of going with the long tubes and then borla exaust. i just dont know if i still need to buy a y pipe....i plan on blowing in the near future...

so he it is my buddy got a turbo wrx and he is trying to personally tune it and his afr meter says its 14-16 bounces in those numbers if im correct wouldn't that make it rich cuz i knew for our x's i heard ten was a good number?