i have an 85 gs rx7 with a 12a. my cats are clogged and i was just wondering how much hp it would give me if i would straight pipe the whole thing, or just hollow out the cats.

 

get a test pipe
it wont be a real lot
but you notice it

i did

 

get a header and make a test pipe there after. if you do not have funding for a header, you can make a test pipe. however, it may only last a few months with cheap tubing. the heat generated by the rotary will break down most cheap piping and mufflers.

 

be careful getting the cats off. try not to cut them off. use heat. you DO NOT want to destroy the exhaust. it will be expensive to replace.

 

How much louder would it be with headers and a test pipe? What would it sound like? I figured it'd sound like a weed wacker on crack.

 

pretty much

 

it will be signifigantly louder but not too obtrusive. to most rotorheads it is just turning up the music. it will have a sharp sound. almost dirtbike like.

 

Id say more of a weedwacker on acid.