No Cat/Straight Pipe= no bottom end. Any engine needs at least some back pressure. If your looking to this to gain bottom end, your barking up the wrong tree. Now it isd a fine line, between too much and too little back pressure. Straight pipe with a decent muffler will probably sound good, but your gonna lose bottom end. For example my race engine has mufflers on it, and tail pipes, Sound crazy? Due to the true tuned headers on it, there was zero restriction. After the engine was built and being tuned on the dyno, there was a 50 lb./ft torque difference from with or without the mufflers.

 

totally makes sernse to me....I was going to post the backpressue bit myself before reading this.....

 

weird, when i redid my exhaust system, i opened it up some, but my muffler was much longer (still a glasspack though) and i gained some bottom end

im still running stock manifolds and downpipes, so there is my backpressure