don7

i was just wondering around how much HP i would pick up if i got a new RB header, high flow cat, and 3" back not shure what brand of muffler yet. just lookin for a range. oh yeah its for a stock 86 gxl

1987RX7guy

iTrader: (3)

15-20hp IMO

bottlejockey

I have a header, no cat, and dynomax mufflers. I can see a certain number, but by far the thing that helped the most was getting rid of the Cat.

don7

i may scrap the cat after i get it inspected, i hate those damn things

bottlejockey

ya i had fun taking a fence pipe and knocking the **** out of the cat. I finally got tired of it leaking and welded in a pipe. It help even more and sound a lot better.

nothinguntil

damn if you get rid of the cat and do all that make you slap on an cold air intake as well. That should give you at least 30 little horses under that rotory powered monster you have there.

don7

sweet deal, now all i need is a job, haha

bottlejockey

I did all the work on my car while I had a job. I moved and still don't have one. It awesome!!!!!

My88Se

iTrader: (10)

meh, you don't need 3" on an NA. 2.25" is said to be th best, maybe 2.5". With 3" you will end up losing power. NA's like a little backpressure, with 3" your not going to get much. Although you have a cat I wouldn't go with three.

What mods do you have done to the engine?

don7

engine is still stock but i want to get a cold air intake, i wanted the new exaust because i want to get the engine rebiult with streetporting done, so then i will already have a good exaust

Dougster

How are you going to get your ports to open if you don't have any backpressure?

1987RX7guy

iTrader: (3)

If your looking for a cold air intake check our site out. CLick on the pic in my sig