gutting cats?

[smokin5s]

Has anyone tried gutting the down pipes? I was talking to a co-worker and my question is, Do you really gain much more going with offroad down pipes as opposed to just gutting the cats?

 

[rubydist]

The exhaust stuff is much more "art" than you might expect. There is a reflected pressure wave every time the exhaust size changes (as well as at the beginning of the honeycomb of the cat) and that would not exist with the "offroad" pipe. This has the affect of making the exhaust pipe appear longer with the "offroad" pipe. In general, making the exhaust pipe longer helps with low rpm torque and hurts high rpm torque. From this simplified explanation, I would suggest that a stock gutted setup might result in more power than a "offroad" pipe. I have not dyno'd these to see if the difference is actually measurable.

 

[Bosscav]

^interesting take. Someone should try this, for science.

 

[markathome]

Seems I remember reading of possible turbo damage and/or over speed from incorrect back pressure conditions....