What causes exhaust rasp?
 

In general, if you take off your cats in a car or truck, what is the actual mechanics of what causes the rasp? Also what is the best way to eliminate rasp on a vehicle with no cats?

I think its caused by the exhaust pulsations. Certain RPM's are ideal and rasp sometimes is unbearable at certain RPM's versus others. My friends TransAm is raspy enough at 2500 RPM's it makes my ears bleed. Dynomax bullets serve well as a resonator. Put one in line right after the y-pipe. Should do the trick.

well right now I have a dynomax ultraflow and no cats on my truck with a y-pipe and its raspy enough that its annoying but the rumble of the muffler sounds really good if you take the rasp away. Do you think if i switched to a super turbo muffler it would be less raspy? Do you think it would be too quiet with the super turbo compaired to the ultra flow?

thanks

ps nice rims on your truck