High flow cats or no cats? - Page 2

GoneBoy · 03-13-2017, 05:03 PM

Quote:

Originally Posted by VAZL1

I've had both and prefer the cats, not a fan of the exhaust smell without them. The performance difference isn't great enough to justify the pain is causes if you're in a state that test as well.

I'm with you on this. I've gone catless before, and those fumes get very annoying very quickly. It would be interesting to see how potent that gas smell is in other 6th gen owners who went catless.

Coat-This · 08-30-2018, 06:24 PM

Quote:

Originally Posted by Can'tHave2MuchHP

You'll melt cats if you modify the car. I used to be a believer in high flow cats for taming the rasp but I've had 3 friends with ZL1s/ZR1s melt cats and pretty much ruin $2,000+ in exhaust systems. The sound cut is not drastic anyways, and the smell for me doesn't exist unless the car is running rich as hell.

How do you ruin a complete exhaust system with a melted CAT? Also, wHo's CAT was it?

Fraxum · 08-31-2018, 01:09 PM

OP besides the catless not too pretty noise, the smell, and none or very little performance gain there is also the responsibility of being an inhabitant of our one and only planet.

Do the right thing and do the cats.

brap999 · 08-31-2018, 02:07 PM

I’ve owned many 60’s and 70’s trucks and cars none with cats, I don’t smell any fumes unless the carburetors are out of tune and its running rich. Tbh I havent run a catless modern car but I can’t imagine it would be worse than a 60’s or 70’s v8

I guess it’s possible I’ve just gotten so used to the smell I don’t notice it

Anyway from the research I’ve done not all aftermarket cats are the same, some are crap and will melt on you. I think you want a GESi cat, which Kooks Green Cats are. Look them up, they are probably one of the few aftermarket cats worth a crap and can handle high temps and HP

VAZL1 · 08-31-2018, 03:06 PM

Quote:

Originally Posted by brap999

I’ve owned many 60’s and 70’s trucks and cars none with cats, I don’t smell any fumes unless the carburetors are out of tune and its running rich. Tbh I havent run a catless modern car but I can’t imagine it would be worse than a 60’s or 70’s v8

I guess it’s possible I’ve just gotten so used to the smell I don’t notice it

Anyway from the research I’ve done not all aftermarket cats are the same, some are crap and will melt on you. I think you want a GESi cat, which Kooks Green Cats are. Look them up, they are probably one of the few aftermarket cats worth a crap and can handle high temps and HP

You most certainly have gotten use to it or lost you sense of smell

laynlo15 · 08-31-2018, 03:38 PM

I just ordered the BBK 1 7/8 long tubes with cats from Phastek. I still drive it on the street some and don't like the smell without the cats unless your just drag racing. Its just a few hp anyway so to me that's not a big deal.

RDBill · 08-31-2018, 05:25 PM

I have Kooks headers and green cats. Absolutely no problem with them and you won't melt one of the green cats. My state doesn't check emissions but they do check to see if you have cats. I wouldn't go without them regardless of what state I live in

PorkchopExpress · 08-31-2018, 05:48 PM

High flow cats!

My wife has vowed to never ride in a car without cats after I daily'd a 2006 HCI GTO without cats. Never again.

laynlo15 · 08-31-2018, 08:37 PM

My cats hate riding in the car. They get really nervous and try to jump out of the sunroof if they can't take turns driving.

Can'tHave2MuchHP · 08-31-2018, 09:17 PM

Quote:

Originally Posted by Coat-This

How do you ruin a complete exhaust system with a melted CAT? Also, wHo's CAT was it?

Because the packing melts/blows out and catches at every bend which can potentially be VERY dangerous for your engine. Short of sending a camera through the system, you have no idea if there's a plug at the X pipe or other choke points like in the mufflers. A plugged exhaust can lead to melted sensors, high temps, over heating, burnt carpet/insulation, burnt off underbody paint, can damage wires and other hoses that are anywhere near it, high trans temps, high diff temps, and even can cost you your entire engine.

Don't chance it. Cat-less or stock. Even the $900 GESI cats fail.

No I don't care that your buddies car lasted 40,000 miles with 4000 RWHP and your last car was fine for 150 standing mile passes.

laynlo15 · 08-31-2018, 10:12 PM

Many cats fail because of tuning. Too much fuel and the cats will fail quicker then a properly tuned engine and you may have issues with the 02 sensors failing also. So find a good tuner that knows what he's doing on the dyno and you'll probably be ok, shitty tuner and you'll be buying new cats in 10 to 15k miles.

kttxz06 · 08-31-2018, 11:17 PM

Quote:

Originally Posted by Coat-This

How do you ruin a complete exhaust system with a melted CAT? Also, wHo's CAT was it?

Um.......................I was close. It's not just that, could of blown my motor at my power level. I deleted my pics, but folks who have followed my build saw what happened. haha. Glad we found out before I started blowing shit up.

kttxz06 · 08-31-2018, 11:18 PM

Quote:

Originally Posted by Can'tHave2MuchHP

Because the packing melts/blows out and catches at every bend which can potentially be VERY dangerous for your engine. Short of sending a camera through the system, you have no idea if there's a plug at the X pipe or other choke points like in the mufflers. A plugged exhaust can lead to melted sensors, high temps, over heating, burnt carpet/insulation, burnt off underbody paint, can damage wires and other hoses that are anywhere near it, high trans temps, high diff temps, and even can cost you your entire engine.

Don't chance it. Cat-less or stock. Even the $900 GESI cats fail.

No I don't care that your buddies car lasted 40,000 miles with 4000 RWHP and your last car was fine for 150 standing mile passes.

^ This.

Coat-This · 08-31-2018, 11:52 PM

Quote:

Originally Posted by Can'tHave2MuchHP

Because the packing melts/blows out and catches at every bend which can potentially be VERY dangerous for your engine. Short of sending a camera through the system, you have no idea if there's a plug at the X pipe or other choke points like in the mufflers. A plugged exhaust can lead to melted sensors, high temps, over heating, burnt carpet/insulation, burnt off underbody paint, can damage wires and other hoses that are anywhere near it, high trans temps, high diff temps, and even can cost you your entire engine.

Don't chance it. Cat-less or stock. Even the $900 GESI cats fail.

No I don't care that your buddies car lasted 40,000 miles with 4000 RWHP and your last car was fine for 150 standing mile passes.

I can certainly see the possibility of CAT's failing, but you lost me on damaged exhaust system, especially ceramic based CAT's. That said, any of your high end CATs are platinum plated SS. The melting point of 304 SS is upwards of 2500F+ and the melting point of platinum is 3200F+, so its unlikely molten SS is spewing from your CAT. Fractured ceramic is even more brittle.

If you have missing shrapnel from a CAT its pretty simple to locate and extricate from the straight pipes on a Camaro. If it made it in a muffler that's a different story but still nothing to get you panties in a bind over or justification for a global ban on CAT's.

This is primarily for stock and mild bolt on applications. Obviously, your 1000hp build would be the exception to the rule.

08-31-2018, 01:09 PM	#17
Fraxum Drives: a M6 LT1 ordered From Becky!!! Join Date: Jan 2010 Location: NJ Posts: 7,520	OP besides the catless not too pretty noise, the smell, and none or very little performance gain there is also the responsibility of being an inhabitant of our one and only planet. Do the right thing and do the cats. __________________ "Democracy Dies in Darkness" My LT1 Keeper ..... ..... My Car Blog CarPlayList, a free App to build USB and Android Music drives.

08-31-2018, 02:07 PM	#18
brap999 Drives: 2018 ZL1 1LE Join Date: Mar 2018 Location: Springfield, VA Posts: 115	I’ve owned many 60’s and 70’s trucks and cars none with cats, I don’t smell any fumes unless the carburetors are out of tune and its running rich. Tbh I havent run a catless modern car but I can’t imagine it would be worse than a 60’s or 70’s v8 I guess it’s possible I’ve just gotten so used to the smell I don’t notice it Anyway from the research I’ve done not all aftermarket cats are the same, some are crap and will melt on you. I think you want a GESi cat, which Kooks Green Cats are. Look them up, they are probably one of the few aftermarket cats worth a crap and can handle high temps and HP __________________ 2018 Chevy Camaro ZL1-1LE 2015 Silverado 2500HD 1999 Jeep Cherokee Sport 1998 Dodge Viper GTS 1972 Pontiac GTO 1963 Chevy C10 short bed, T5, 350, lowered

08-31-2018, 03:38 PM	#20
laynlo15 Drives: 2022 Lt1 A10 Join Date: Nov 2015 Location: clark, mo Posts: 8,860	I just ordered the BBK 1 7/8 long tubes with cats from Phastek. I still drive it on the street some and don't like the smell without the cats unless your just drag racing. Its just a few hp anyway so to me that's not a big deal. __________________ 2022 Lt1 6.2 A10, Maggie 2300, THPSI Port Inj/10 rib, Rotofab, E, Nickey, SCOL, Griptech, RC Bandits, Hoosiers/MT 9.80@142.96 1.44 60ft, 6.34@112 707/669 RWHP/TRQ. 16SS Maggie 2650 9.41@147 1.35 60ft, 5.99@119. 16 C7 A8 10.90@128 Bolt on stuff

08-31-2018, 08:37 PM	#23
laynlo15 Drives: 2022 Lt1 A10 Join Date: Nov 2015 Location: clark, mo Posts: 8,860	My cats hate riding in the car. They get really nervous and try to jump out of the sunroof if they can't take turns driving. __________________ 2022 Lt1 6.2 A10, Maggie 2300, THPSI Port Inj/10 rib, Rotofab, E, Nickey, SCOL, Griptech, RC Bandits, Hoosiers/MT 9.80@142.96 1.44 60ft, 6.34@112 707/669 RWHP/TRQ. 16SS Maggie 2650 9.41@147 1.35 60ft, 5.99@119. 16 C7 A8 10.90@128 Bolt on stuff

08-31-2018, 10:12 PM	#25
laynlo15 Drives: 2022 Lt1 A10 Join Date: Nov 2015 Location: clark, mo Posts: 8,860	Many cats fail because of tuning. Too much fuel and the cats will fail quicker then a properly tuned engine and you may have issues with the 02 sensors failing also. So find a good tuner that knows what he's doing on the dyno and you'll probably be ok, shitty tuner and you'll be buying new cats in 10 to 15k miles. __________________ 2022 Lt1 6.2 A10, Maggie 2300, THPSI Port Inj/10 rib, Rotofab, E, Nickey, SCOL, Griptech, RC Bandits, Hoosiers/MT 9.80@142.96 1.44 60ft, 6.34@112 707/669 RWHP/TRQ. 16SS Maggie 2650 9.41@147 1.35 60ft, 5.99@119. 16 C7 A8 10.90@128 Bolt on stuff

08-31-2018, 05:25 PM	#21
RDBill 902HP 858TQ Drives: 2018 ZL1 A10 Join Date: May 2018 Location: New Jersey Posts: 135	I have Kooks headers and green cats. Absolutely no problem with them and you won't melt one of the green cats. My state doesn't check emissions but they do check to see if you have cats. I wouldn't go without them regardless of what state I live in

08-31-2018, 05:48 PM	#22
PorkchopExpress Drives: 2018 Camaro ZL1 Garnet Red Join Date: Jul 2018 Location: Kirkland, WA Posts: 24	High flow cats! My wife has vowed to never ride in a car without cats after I daily'd a 2006 HCI GTO without cats. Never again.

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