pontiac

iTrader: (4)

06 ls2 car (C6)
1 7/8th headers, magnaflow muffls and tips.

I am running the catted one now, and like the sound. It could be alittle louder, but love it. how much you think going to the off road x pipe would change it?

I have been told they do not change he sounds that much. thoguhts?

I ask becasue I have a guy taht wants my off road x-pipe and i had just about given up and was going to put it on, but I want to double check my desision before selling.

Mike P.

I'm curious about this too. One, because of the sound. And Two, I wonder how much more RWHP & RWTQ a person would stand to make by using the Off Road Mid Pipe vs. High Flow Cats.

Currently, I've got Kooks 1 3/4 Long Tube Headers with High Flow Cats, and the stock axle back system. But I was thinking about using off road mid pipes instead of my current high flow cats.


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pontiac

iTrader: (4)

there is no power to be had, its all sound. but the question is how much sound. is it worth it to disasemble and put back to gether or just sell the extra and keep what i got.

cowboyup

iTrader: (4)

Trust me... Its Louder..

I picked up 8rwhp across the band going from HF Kooks Cats to Kooks X-pipe..

I like it better without...

speed_demon24

iTrader: (6)

Magnaflow 59959 bullet cats didn't change the sound of my car at all. I cut them off 6 months later since they were getting smashed up.

pontiac

iTrader: (4)

well the ones i am wanting to know about are American racing high flow cats

BigRich954RR

iTrader: (1)

The more power your making the more hp no cats will give you same with sound
My car 400hp with no cats like 4hp very little sound change. When i went to 750hp no cats added 40hp and changed the sound a lot

c5z28

iTrader: (11)

I went from no cats to cats and the sound is alot quiter. You will hear it, and feel it.

blk/slvr02ss

iTrader: (21)

I took my SLP High Flow Cat's off my last SS and only went 1/10 faster in the 1/4 and a little bit louder.

good2go

I ran my 07 Z06 with American Racing headers and high flows for a while, then gutted them. It was significantly louder and a deeper tone. Can't comment on hp gain.

Danny

iTrader: (16)

When removing the cats do you guys get that stink from the fumes. I want to remove mines but i don't want my car stinking like a car running rich as hell.

OneQuickCoupe

iTrader: (1)

I'm running a Kooks off road X and it does smell. You might like the smell but I'm not really fond of it.

LSXNOVA

JosephIV

iTrader: (14)

I have a local friend with LT's and ORX on his C5 and his exhaust smells as badly as my LT's and ORX Z28. Eye watering rich fuel smell.

If the car is a daily driver I'd keep the cats. The smell gets old on daily commutes to work etc. Sit in traffic for 45 minutes and you'll wish you had cats on the car.

RedRallyeZ

iTrader: (20)

i dont mind the smell anymore, i cant smell it,

i wont say its bad, ill say that i can be strong at first. now i can only smell it if ive got the car running and go around the back, or if i let it warm up in the garage. cant smell it at stoplights or anything

LS1LT1

iTrader: (16)

That's not entirely true...as others have stated there are in fact power gains to be had by going from high flow cats to off road pipes but they are often quite minimal (maybe 5-8rwhp).
On a cammed or heads and cammed car it means even more too.

pontiac

iTrader: (4)

Ok so I got bored and swapped the x pipes. (had the hi-flow cats on, now off road on) its a little deeper, but did not change that much. It will get louder after 4000 than before, but below that is close to the same. I do not think you could tell unless you heard it ack to back at WOT

billybob270

Hello,
I was reading your comments on the exhaust smell w/o cats. I have a '06 GTO LS2 engine that I was going to transplant in an older car...therefore, a lot more air leaks into the car due to 70's door/truck seals....can you smell the rich exhaust smell when it is completely stock minus cats? Also was there a noticeable increase in exhaust when adding bolt-on's and cam? Thank you.

BigRich954RR

iTrader: (1)

the smell comes from the tune i have a 06 GTO no cats with stock tune with little adjustments almost no smell when warm now with bigger cam and 60 lbs injectors and tuned for more power it smells alittle more. When engine warming up you can smell it alot

allforspeed

iTrader: (1)

personally i can't understand why people run without cats. i know its not a popular thing to say on this site, but damn, why would you literally want to just pollute the air that is in the area you and your family live in?? is that worth the 6hp or whatever you may gain? you drive your car generally where you and your family live and work right? well then "that smell" of toxic chemicals in the air will also be where you and your family live and work. i know its a very small amount, but go to china or mexico city where nobody cares about that stuff and see what it gets them. i know its worth more power and i would personally never run without cats just because its not worth it to me to ruin the air i breath any more than i have to. obviously driving at all is not great for the air but the cats are very effective and going out of your way to take them off just for a very small amount of power seems irresponsible.

i'll get off my soap box now. but there is more to it than just sound and power.

salemetro

iTrader: (5)

Agreed To me, the thought of building a street car that won't make emissions testing is kinda crazy...unless it's a true race car. I want to know that if I move to an area where there is DEQ testing, my car will pass. That's my motivation. I want to be able to drive/live wherever I feel like it. Not to mention that I think it's kinda cool being able to say that even with xxxhp/tq, my car still makes emissions standards.....unlike the ricers with the fart cans.