3" exhaust question -
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Car: 1989 5.7 IROC Dark Red/Blk 92Z28
Engine: 5.7
Transmission: 700R
3" exhaust question -
I just picked up an 89 IROC, with 80,000 runs good. Tried to get it inspected but the exhaust system failed. Guy said pipe before the cat had a leak and it needed a muffler.. and basically some pipe work. I have a 3 inch exhaust I took off a 92 Z with a 5.7 absolutely NO rust and has a flow master muffler and exhaust tips. I'm wondering if I could use this system. I have the 5.7 TPI bone stock and according to the RPO codes the car has a 2.77 rear end gear (which I plan to change out before spring to maybe a 3.42
stone
stone
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Car: 92 T/A 'vert
Engine: Mild .040 over L98 4 bolt mains
Transmission: Mostly stock 700R4, 2600 Vigilante
Axle/Gears: LS1 3.42
Re: 3" exhaust question -
I'm thinkin' the 89 has a single converter and the 92 is probably dual. It will bolt up to the manifolds but may give your inspector the bends due to the difference even if it passes the sniffer.
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Car: 1989 5.7 IROC Dark Red/Blk 92Z28
Engine: 5.7
Transmission: 700R
Re: 3" exhaust question -
Yes, the new exhaust has two cat's.. Do I cap off the line on one of the cats going that goes out to the motor ?? (the skinny little tube..both cat's have one)
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Car: 1989 5.7 IROC Dark Red/Blk 92Z28
Engine: 5.7
Transmission: 700R
Re: 3" exhaust question -
Ok, installed my 3" exhaust on my 89. You were right, it did need a little modification with the extra cat but it worked out. the only thing is it's kinda loud. Sounds like I have a big block 396 under the hood. My goal is to put in a 2 1/2" I read somewhere it would help me out with the back pressure. Stone
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Car: 1992 Camaro Z28
Engine: 350ci
Re: 3" exhaust question -
I agree LB9GTA stick with the 3" If anything you might change the Flowmaster muffler for something like a Dynomax Super Turbo. As an aside, did you notice any seat of the pants power gain from the dual cats?
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Car: 1989 Iroc-Z Camaro
Engine: TBI,5.0
Transmission: Automatic 700R4
Axle/Gears: Eaton Posi,3.42,LPW Ultimate Cover
Re: 3" exhaust question -
As "watajob mentioned ,I also don't see how a exhaust system with two cats is going to pass a visual inspection.
Last edited by Ron U.S.M.C.; 02-19-2013 at 02:53 PM.
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Car: 1989 5.7 IROC Dark Red/Blk 92Z28
Engine: 5.7
Transmission: 700R
Re: 3" exhaust question -
We'll it did pass.. From what I understand the newer third gens came with dual cats, but don't hold me to that. He looked under there, said cats look ok, hooked up the machine slapped the inspection sticker and I was gone.. Not going to worry about it, just glad to be driving my car! Stone
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Car: 1989 Iroc-Z Camaro
Engine: TBI,5.0
Transmission: Automatic 700R4
Axle/Gears: Eaton Posi,3.42,LPW Ultimate Cover
Re: 3" exhaust question -
Yeah, I'd be sure to uses that guy all the time with your smog testing.
Nice to hear you passed though. Have fun with your new car.
Your saying you have a 9 bolt so a new gear ratio from 2.77 to 3.45 and a posi.(if you don't have one already) will make a huge difference,you will love them.
Here's a link to a thread concerning the 9 bolt = https://www.thirdgen.org/forums/faq-...now-about.html
Nice to hear you passed though. Have fun with your new car.
Your saying you have a 9 bolt so a new gear ratio from 2.77 to 3.45 and a posi.(if you don't have one already) will make a huge difference,you will love them.
Here's a link to a thread concerning the 9 bolt = https://www.thirdgen.org/forums/faq-...now-about.html
Last edited by Ron U.S.M.C.; 02-19-2013 at 06:56 PM.
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Car: 1992 Chevrolet Camaro Z28
Engine: 5.7 TPI
Transmission: 700R4 Overdrive Automatic
Axle/Gears: 3.23:1 Positraction
Re: 3" exhaust question -
I have the 3" Flowmaster 80's Series System with dual cats on my 92 Z28 L98 and it sounds awesome like a Monster that's how I always wanted it. BEAST. if I wanted it to be not so loud and just moderate I would have kept it stock.
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Car: 1989 5.7 IROC Dark Red/Blk 92Z28
Engine: 5.7
Transmission: 700R
Re: 3" exhaust question -
Ok I must just be missing something.. My car is an 89, and 89 was the first year for dual cats and so my car shouldn't pass because "___________________" ? Please fill in the blank, just the blank..
As far as the car sounding like a monster, dude you're right ON. I have the exact same thing you do ( I think, says 80 series dual cats 3") I'm getting use to it, getting on it is fun, like you said... sounds like a beast.
Stone
As far as the car sounding like a monster, dude you're right ON. I have the exact same thing you do ( I think, says 80 series dual cats 3") I'm getting use to it, getting on it is fun, like you said... sounds like a beast.
Stone
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Car: 1990 G92 IROC Z Miniram
Engine: 388cu 6.4 Liters
Transmission: G-Force T5
Axle/Gears: 3.73 Gears
Re: 3" exhaust question -
Ok I must just be missing something.. My car is an 89, and 89 was the first year for dual cats and so my car shouldn't pass because "___________________" ? Please fill in the blank, just the blank..
As far as the car sounding like a monster, dude you're right ON. I have the exact same thing you do ( I think, says 80 series dual cats 3") I'm getting use to it, getting on it is fun, like you said... sounds like a beast.
Stone
As far as the car sounding like a monster, dude you're right ON. I have the exact same thing you do ( I think, says 80 series dual cats 3") I'm getting use to it, getting on it is fun, like you said... sounds like a beast.
Stone
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Car: 1989-92 FORMULA350 305 92 Hawkclone
Engine: 4++,350 & 305 CIs
Transmission: 700R4 4800 vig 18th700R4 t56 ZF6 T5
Axle/Gears: 3.70 9"ford alum chunk,dana44,9bolt
Re: 3" exhaust question -
As stated above, 89-92 N10 is the dual cat option on 350 tpi auto and tpi 305 5spd cars with certain performance options.
FYI: backpressure is bad
FYI: backpressure is bad
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