I have a Cobb tuning cat back. The sound level is just the way I like it...not too loud. However, after I installed a downpipe and got rid of the 3rd cat, it got a bit louder than I'd like.

If I had a shop add a resonator to the straight rear pipe, would it do much to tone down the volume?

 

I dont know exactly hom much quieter but they really work iknow that.

 

they actually work pretty good. i think greddy uses two or three in their evolution exhaust.

 

More resonators would impede the flow velocity of exhaust gases though, right? And that it turn would hurt performance? Just curious