Slowbalt89

Anybody just gut the cats in the stock down pipe looks like it should flow pretty good factory

kzak104

iTrader: (1)

a catless downpipe is so cheap its not worth the work of gutting a stock one imp, also a catless pip is one smooth pipe, the stock one has dimples and crap.

Slowbalt89

Well I'm rebuilding my turbo and already have it off so figured I'd do it anyway lol trying to grab small horsepower where I can

joezombies

I die mine with a hammer a couple long screwdrivers and a chisel. It was easy and IMO sounds nice and throaty. I think having to wider empty chambers where the cats were may help with the sound resonance, but that's just me. And it certainly seemed to make the Turbo spool up a lil quicker although others may disagree.I also fail to see how buying a catless downpipe is anywhere near as cheap as gutting the stock one seeing as its free. Also is recommend buying an o2 sensor defouler mine will kick a code for the cat when I take highway trips. And a defouler from.vibraint is only like $25

nobody2u

I've heard that gutting cats isn't a good idea. Also just get an aftermarket downpipe so its 3" instead of 2.5".

CordiaDOHC

iTrader: (2)

Buy a non catted downpipe. Gutting a stock catted downpipe can cause turbulence in the exhaust and not actually give you as much of a gain as you would think.

joezombies

hmm id think that the exhaust gasses would be swirling like a cyclone coming out of the exhaust turbine of the turbo and wouldnt be effected that much, maybe dyson should make an exhaust with cyclone technolgy it would just suck those exhaust gases right out

Slowbalt89

Pretty sure that it's a 3 inch anyway I checked it with a micrometer and these cats are huge I figure I might as well punch it since it's off and I'm rebuilding the turbo guess I will have to see but it won't be entirely accurate because I'm porting the turbo and elbow from the manifold

Macgyver2484

iTrader: (3)

The restriction is where the o2 sensor is. The pipe is pinched into a 2” hole. I’m sure someone is selling a used downpipe on here for $100 somewhere. No need to ruin a good catalytic converter. If you’re that low on money, buy a used downpipe and sell the stock pipe. You won’t lose any money and you’ll get the performance you want.

Slowbalt89

Too late lol screw driver and hammer has already found it

joezombies

LOL I gutted mine because of driveability. My car was all kinds of f***ed. Didn't have time or money for downpipe and my primary cat had partially came apart clogging the smaller section and the secondary cat.. ran like new afterward!

Slowbalt89

Nice does it sound any better

reaper89

iTrader: (2)

just search the classifieds for a catless DP, i picked mine up for 90 shipped. Best mod i did besides my tune, sounds so nice with the stock cat back.

FasterIsBetter

No, its not 3 inch ID...3 inch OD maybe...oh well, gutting the cats isn't a very good idea at all to do on a newer car especially if you're that cheap cause I'm sure you're going to need a warranty if you can't afford a downpipe...could have saved the stock dp for warranty work.

joezombies

Yeah you fan even hear the wastegate open when you let off the gas coming out of boost. And warranty smarranty. The dealership I took my car to couldn't even find the problem with my car and charged me money. Even my father that hasn' been a cgm tech since the 70's told me it had to be clogged ehaust. They dealership replaced a plastic airbox and told me it was fine. And it wasn't. I even dealt with gm and got the complete run around and they wouldn't evn take responsaibility for their dealership. Idk what th dealersp thinks a ss/tc cobalt is even supposed to run like!

kzak104

iTrader: (1)

You can hear the waste gate open? Lolwut. Maybe the diverter valve but u hear that with a air intake, not a catless downpipe...

09sscalicobalt

iTrader: (1)

cheapskate lol

Wangspeed

iTrader: (2)

Hope you wore a mask. It's pretty carcinogenic.

joezombies

really??? after i was done i pulverized it, got a mirror, a $100 bill, and did lines

joezombies

well when im in boost and let off the throttle you can hear the exhaust get loud and throaty for a second or 2 just like when an external wastegate opens, only the sound comes out of the end of my exhaust.

Wangspeed

iTrader: (2)

You can joke all you want, and it's funny til you've had to go through cancer, or support someone going through it.

I just past my 1 year anniversary, and I wouldn't take a risk like that. You feel invincible til you get a life threatening disease or injury.

joezombies

Did **** just get serious? I've been surrounded by cancer. And its not about feeling invincible to me. Its my attitude that if its my time to go its my time to go. I've been through a lot of **** where I definitely should have died. There ain't **** you can do about it if its your time to punch in. No ammount of money in the world will prevent it. And no ammount of precaution will stop it.

duramaxdave

Not worth the headache, just buy a dp. With any turbocharged vehicle the faster you can get that exhaust out the better. One of things that kill the flow is all of the factory exhausts is the kinks and bends. My duramax had such a pinched off down pipe it was rediculous, put a dp on it and huge difference in spool up

duramaxdave

Amen to that. Three of my grand parents past away from cancer

CordiaDOHC

iTrader: (2)

4.5 years in the clear myself. Stage 3.
**** sucked... 3 months of 8 hours a day chemo. Pass! Im a lot more careful with stuff thats known to give people cancer now!