I was wondering what kind of gains (if any) I'm gonna feel on my car (87 N/A) from the following mods: RB or bonez straight pipe + presilencer + Cat back exhaust (single) GIVEN the fact that the previous owner already removed the cat and placed a piece of tube (looks about 2" OD) then a ~18" resonator and then looks like 1.5"od pipe to a cherry bomb muffler at the end?? to make a single exhaust.

thanks.

 

you will see improvements by far the best mod to gain hp is to uncork the exhaust...Although the main cat was replaced you will still see a difference because your getting rid of the main cats. It may sound a little ricey or buzzy with only 1 presilencer i would atleast add another but then again it may still buz my friend has the same setup and it buzzed so bad it didnt even sound like a true rotary engine sounded like a damn honda