F1 Bomber

Okay so I just purchased my 85 firebird with a 305 HO a few days ago, and am planning on getting the exhaust done right away. I am either going to

a) Take the catalytic converter off and go straight pipe

b) Take the catalytic converter off and go with a Flow Pro muffler.

Could anyone give me the estimations on the gains I would get horsepower wise?

UnderCover89TBI

iTrader: (25)

not that much. and its illegal either way buddy. i guess if i had a choice id put the fake converter there so at least visually you'll look okay..now unless they check the #'s on it...

F1 Bomber

Well actually, I am from Canada, and it isn't illegal here, the worst I can get is a $90 noise ticket. Also I am mostly curious about which one will give me the biggest increase. I know it wont be much but I would still like to know.

//<86TA>\\

iTrader: (14)

straight pipe will give the most "increase", but its still negligible at best. Unless the cat is clogged. Perhaps pickup a aftermarket hi flow cat? it will keep the car from smelling bad, and wont cost much if any power. you most likely wont feel any difference in performance between a straight pipe there, and a high flow car.

the most increase you will notice from the exhaust would be to swap out the stock exhaust manifolds and y-pipe to aftermarket headers and y-pipe. You will most likely feel this change.

F1 Bomber

I am talking about taking BOTH the cats off and the muffler.

///DAN///

iTrader: (1)

my friends z28 was like that it was pretty loud and popped like crazy you need to have some back pressure or you could accualy lose power.

F1 Bomber

I was thinking that but wasn't sure, so basically the Flow Pro would be the better option then.

built91Z28

I would defiently have some sort of muffler.

Gumby

straight shot classic cherry bomb put where the cat goes, then straight pipe out the back, no axle loop.