How much would you say I would gain in HP if I were to gut the cat in an 1981? It was fried so I guess it cant be any worse then it was!

 

If youre gutting cats, then go ahead and remove air pump stuff while you're at it.

 

HP gain, not much. Installing a straight pipe in place of the cat will give a better gain since there's so much turbulence in a gutted cat. First and best hp gain is installing headers and a free flowing exhaust system. Rotarys are hard to quiet down so the stock exhaust is very restrictive.

 

Thanks for the advice guys.

 

Hi there i have a 1986 FC3S stock standard and want to crank the boost up at the moment its sitting at 6psi, is it possible to install a boost controller to crank it up and what boost could i get to, before i have problems. Cheers

 

Holy hell thread jacking... and not even related.

Start a new thread, or better yet, search. Lots of threads already on the topic.