I have gutted pre-cats, a Black Dragon Automotive replacement cat, and the HKS cat back. I like the sound of it. Not too loud but you can hear it when I really get on it.

I have the RB header, Mazdatrix hi flow cat, and the RB ypipe setup. Not tooo loud but I try and soft pedal it in my neighborhood. nice sounding to me. Even the wife thinks it sounds cool, if she doesn't have to ride in it! https://www.nopistons.com/forums/pub...IR#>/blink.gif



I plan to do a single 3" pipe back from the cat and one hi flow exhaust muffler that can be removed and replaced with a pipe on race days... we hope the cat will knock down enough noise to pass track db... Reduces weight and hopefully avoids the 1-3 hp a Y-pipe robs. We'll see how it does... Jeff Clark is going to work with me on this. https://www.nopistons.com/forums/pub...IR#>/bigok.gif

the old greddy and the old hks (now called the sport) sound great!

makes sense