JDMZ28

iTrader: (1)

I'm about 99% sure my cat is blown on my T/A. A shop said they'd make me a bypass pipe for 30-40 bucks. I was wondering how hard it is and what is involved in gutting a cat? I'd assume you just dig out all the insulation, but I've heard in the past you have to put a pipe in through the middle of it. Can somebody enlighten me? I never had to go through this with the camaro it was removed before I bought the car.

Not that this is the reason I'm removing it but I was wondering if there is performance to be gained from removing it?

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1986 CAMARO Z28 ->
151,000 original miles, 43,000 on 89' vette 350 block, Holley 650 DP, Weiand intake, 1.6 rockers, 1 5/8" headers, no cat, 2 1/2" Flowmaster catback, Mallory coil, March pulleys, B&M Ripper shifter, T5 with 3.35 1st gear and 0 miles, 90% Centerforce clutch, 3.73 posi, Eibach 1" drop springs, Spohn LCA's, Spohn adjustable panhard rod, Subframe connectors, all bushings are urethane, 2 12" Sound Streams, 2 Infinity 6X9's, 2 Pioneer 6X9's, 800 watt Lanzar Vibe amp. ET 13.32@ 106.4MPH 3300lbs less driver and speakers Next mods-> Extreme Energy 268 cam, Holley street dom intake, ported heads.

1987 TRANS AM ->
73,000 miles, 305TPI, auto, gutted air box, gutted cat.

Tas

if its good no. If its bad then yes. The only reason anyone should gut a cat is for sound. If you expect there to be a differeance in perfromace between a new cat and no cat, you're wrong.

As for gutting it, put it on the ground. stab it with a crowbar or big screwdriver, put it on the car without the catback, blow out the broken pieces. I'd just have the place put a pipe through it or in place of it if you don't want one. If you want a new one, summit sells Catcos at a good price www.summitracing.com

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-Tas
'89 Formula WS-6

305, TBI, auto, 14x3 chrome flat based open element with K&N, Milodon 160* thermo, functional Formula hood, cross-flow Flowmaster, '99z28 rear pipes and tips....

Soon to be installed:
Hooker 1-5/8" 50 state legal headers, Dynomax 3" I pipe (PN 44063 and 43248), Catco 3" cat, and injector spacer.

Super GRK_Taz World
F-Body Dual Exaust
EFI & Intake Options
AOL IM: superGRtaz

JDMZ28

iTrader: (1)

What will it do for sound? My impression was it would have the same exact tone just be louder. What way would you describe it?

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1986 CAMARO Z28 ->
151,000 original miles, 43,000 on 89' vette 350 block, Holley 650 DP, Weiand intake, 1.6 rockers, 1 5/8" headers, no cat, 2 1/2" Flowmaster catback, Mallory coil, March pulleys, B&M Ripper shifter, T5 with 3.35 1st gear and 0 miles, 90% Centerforce clutch, 3.73 posi, Eibach 1" drop springs, Spohn LCA's, Spohn adjustable panhard rod, Subframe connectors, all bushings are urethane, 2 12" Sound Streams, 2 Infinity 6X9's, 2 Pioneer 6X9's, 800 watt Lanzar Vibe amp. ET 13.32@ 106.4MPH 3300lbs less driver and speakers Next mods-> Extreme Energy 268 cam, Holley street dom intake, ported heads.

1987 TRANS AM ->
73,000 miles, 305TPI, auto, gutted air box, gutted cat.

calroc

The sound will be louder and much more "blatty". As far performance is concerned, with Tas' mods there would be no gain. With 13 second mods such as yours, I'll bet you'll see a difference. With people feeling a difference between 1 5/8" headers and 1 3/4" headers, 2 3/4" cat-backs and 3" cat-backs, why would there not be a difference removing something you can barely see light through?

JDMZ28

iTrader: (1)

I think he was refering to the T/A. Your looking at the camaro, the cat has been long gone on the camaro. The T/A is bone stock.

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1986 CAMARO Z28 ->
151,000 original miles, 43,000 on 89' vette 350 block, Holley 650 DP, Weiand intake, 1.6 rockers, 1 5/8" headers, no cat, 2 1/2" Flowmaster catback, Mallory coil, March pulleys, B&M Ripper shifter, T5 with 3.35 1st gear and 0 miles, 90% Centerforce clutch, 3.73 posi, Eibach 1" drop springs, Spohn LCA's, Spohn adjustable panhard rod, Subframe connectors, all bushings are urethane, 2 12" Sound Streams, 2 Infinity 6X9's, 2 Pioneer 6X9's, 800 watt Lanzar Vibe amp. ET 13.32@ 106.4MPH 3300lbs less driver and speakers Next mods-> Extreme Energy 268 cam, Holley street dom intake, ported heads.

1987 TRANS AM ->
73,000 miles, 305TPI, auto, gutted air box, gutted cat.

Tas

the inside of a cat is a brick of ceramic matieral and exotic metals. the pattern of the block is make up of horizontal and vertical lines sith tiny square pathways all the way though the cat. the area of the square pathways is just as great if not greater than the area of the pipe. Just because you can't see though it clearly, doesn't mean it can flow. If you drive past a field of tall crops you can only see the ground between several lines of crops at a time, does it mean that there is no ground bewtween the other crops because you cant see them all at once? Of course not. The light shining though a cat is the same way. you will only see light from the square pathways directly in front of you.

Tas

hmm after talking with some people I should clarify my opinions. Just becuase I think some thing is a certain way, doesn't mean it is. anyhoo:
Cats don't have to rob you of power even though they usualy do. A good set up cat system can take away 0% of your power and maybe 1% max if its set up right. Cats don't need to be ditched just to make power. I don't like the trend of people doing that. Our 3" cats(aftermarket exaust) are in the worst place to put a cat. Dual 2.5" cats in the Y pipe would give 28% more area and take away less flow. I hope I confused you enough now

RICHRAD

Don't gut it if you can remove it and get by without it where you live. Finding a shop that will weld in a pipe is great! Won't happen where I live. You'll notice a little better mileage and a little more throttle response. For me ,that and a dual snorkel was the difference in smokin'em. As for backpressure , the stock exhaust pipe and muffler is plenty.