how much hp gain could i expect from a NA 88 coupe by taking off the cat and replacing it with a pipe, and what effect would this have on my car.

i know about how it wouldnt pass emissions but i have friends that have friends and all..

 

take off all the cats and it will make a good difference. you have atleast 2, maybe 3.

 

Depending on weather or not you have a cone filter and catback to go with the pipe replacement, you could see anywhere from 5-20HP gains. It really depends alot on what else you have done to the car and what condition your motor is.

 

For what it's worth I have a high flow main cat, and gutted my 2 pre-cats. Yes I felt a nice gain. better idle too actually. Ofcourse my main cat WAS clogged.

I also had the pacesetter exhaust on it. When I put my stock system back on, I noticed a very minimal power loss. Gutting the cats have been the biggest gain so far for my car. Next in line is either a GOOD cat back system or a nice set of headers.