9D4Z28

i just bought a 3 inch high flow cat and a 3 inch pipe after the cat. i was wondering is there really that much difference in power gain between the
high flow cat and just cutting out the cat?

also how much horsepower will i gain from the high flow cat? and how much if i just cut it out?

monster81

gains is very minimal imo, u might not even notice it. deleting the cats definatly helps a bit especially at high RPMs,,,u will notice the change in the exahust roar tone

big_bird_93

iTrader: (1)

I made the choice a couple months ago to have the cat gutted. But it would backfire and pop. I got sick of it quick. Now i have a 3" magnaflow high flow converter and 3" magnaflow y pipe running to the slp lm1. Its still just about as loud but the tone sounds better. and no backfires.

StealthFormula

iTrader: (35)

I ran a Magnaflow high flow cat on my ORY years ago and would switch back and forth between that and a piece of straight pipe with no difference in power felt. Even sounded pretty much the same just a tad bit louder with the cat out.

monster81

gutting the cats cant be the cause of the backfire, if ur exhaust backfires then u have a problem with ur engine (could be ignition,fuel,PCM...) have it checked

Elliott's94Z

iTrader: (12)

Best Cats on the market http://www.frozenboost.com/product_i...4dc11f7f10267a

myltwon

iTrader: (1)

cats keep the fuel stink away which is always a plus, never run a gutted cat though. either high-flow or delete it altogether

ss.slp.ls1

iTrader: (36)

+1...

big_bird_93

iTrader: (1)

Could it be because it is not tuned? or do i have bigger problems? I know i need to get it checked out. sorry for the hijack...

big_bird_93

iTrader: (1)

C**ksucker at the shop pulled me to the side and talked real low.. "wanna make your car faster? We can just gut the cat or you can wait on the 800 dollar magnaflow converter." Should have smelled somethin fishy and taken my car home. Wont return to that shop.

monster81

according to ur signature i dont think 'tune' is the issue,,i remember couple of years back i had a bad backfire, it turned out to be my spark-plug wires, engine was runing on 7 cylinders ..(common LT1 issue),,so i changed the wires and the back-fire issue was solved, but was still feeling something was wrong, then i swaped in a new opti,,,it ran perfect
im not sure bout urs, imo ignition system is where u have to start inspecting...

93M6Formula

Not to steal this thread, but my 93 formula backfires like a mother when i down shift too?! WTF?

black_sunshine

still highjacking....


it is common but can be tuned out. It's just unburnt fuel igniting in the header, meaning your runnin a tad rich. Most lt1's do!

SimRacer1

My 02 H/C WS6, had true duals with longtubes down to an x pipe to bullets then dumped facing downwards, 3" all the way through.

After I added a pair of 3" Magnaflow Hi-flow Metallic Cats between the collectors and xpipe my car went from ridiculous loud, to just loud. It went from sounding like a prostock dragster at idle to sounding like a boat at idle lol. I think it helped the low end power a bit but pretty sure the top end has suffered a bit.

BUT I cant fully blame the cats. When I added them, I also had the exhaust extended out back. So after the bullets, the remaining piping out back was reduced to 2.5" AND its crush bent not mandrel.

So how much of the performance and sound volume was lost due to the cats, reducing exhaust after bullets to 2.5" or cause of the crush bends, its really hard to say.

I have to admit, when you get on it its still loud as **** and it still screams up top, and the cats seemed to get rid of that high pitched metallic sound our cars are known for when you let off the gas at high rpms.

Heres a vid of the current setup. I only brought it up to about 4500 rpms, and was at 75% throttle not WOT.

http://www.youtube.com/watch?v=TYLGZjaWrRs

hitmanws6

iTrader: (20)

the high flow cat will cost you roughly 2rwhp compared to a straightpipe

SimRacer1

I think its much more than 2rwhp unless the car is still on its cat tune. When you remove cats and upgrade exhaust you are generally supposed to have a richer tune. So now when you add your cats back on the optimum tune will be off as it will now be too rich for your current setup. So maybe if you re-tune the car with the cats on maybe then it will be 2rwhp.

Thats atleast what ive read i more than one place. The optimal tune for a catless system is richer then the optimum tune for the same system with cats on.