Just bought a Flowmaster Cat-Back
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Joined: May 2006
Posts: 98
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From: Sterling, VA
Car: 1987 Camaro IROC-Z
Engine: 350 5.7 TPI
Just bought a Flowmaster Cat-Back
Hey guys, I just ordered a Flowmaster 17233 American Thunder cat-back to replace my stock exhaust. I was just wondering if there are gonna be any difficulties i should prepare for in installing it or removing the stock one. I read the pdf instructions on the Flowmaster site and it seemed pretty straightforward except for the part of cutting the original exhaust to remove it. Did anyone really have to do this in removing the stock exhaust?
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Joined: Jul 2003
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From: any clime or place...
Car: 1987 Camaro SC, 1999 Z28
Engine: GMPP 350HO, LS1
Transmission: Built 700r4/EDGE 3200, T56
Axle/Gears: 3.42 Eaton 7.625, 3.42 Zexel Torsen
should be good to go...86-91 3" single cat application right?
next on the list: hooker 2055's! highly recommend, look into it.
any pics of the z? I have a soft spot for 87's...
next on the list: hooker 2055's! highly recommend, look into it.
any pics of the z? I have a soft spot for 87's...
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Joined: May 2006
Posts: 98
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From: Sterling, VA
Car: 1987 Camaro IROC-Z
Engine: 350 5.7 TPI
yeah i need to wait for some more funds before i get the hooker 2055s which i plan on getting. Sorry no pictures yet, after the exhaust i plan on getting it painted (bought it with a few scratches and fading), then i'll have some pics.
I bought this car a few weeks ago but i plan on doing as much as i can to it throughout the summer.
I bought this car a few weeks ago but i plan on doing as much as i can to it throughout the summer.
Joined: Jul 2003
Posts: 10,525
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From: NYC / Jersey
Car: 1990 Trans Am GTA
Engine: Turbo 305 w/MS2
Transmission: 700R4
Originally Posted by Rosadoc-Z
I read the pdf instructions on the Flowmaster site and it seemed pretty straightforward except for the part of cutting the original exhaust to remove it. Did anyone really have to do this in removing the stock exhaust?
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From: mid GA
Car: 88 IROC
Engine: 305 TPI w/ l98 cam
Transmission: T5 5-speed
Axle/Gears: 3.45 posi disc 9 bolt
Originally Posted by Rosadoc-Z
has anybody had any issues with the slip fit connections? has anybody gotten it welded?
Joined: Sep 2003
Posts: 25,895
Likes: 429
From: Pittsburgh PA
Car: 89 Iroc-z
Engine: 555 BBC Turbo
Transmission: TH400
Axle/Gears: MWC 9” 3.00
a hacksaw sucks when your workin with smaller jack stands
get a sawzall. it makes it sooo much easier to cut that pipe out.
the only other thing you gotta look out for is the bolts to the cat. those could be rusted out and hard to move.. so PB blaster them before hand.
and make sure you clamp those clamps down VERY tight. i had mine tight but the back muffler fell off one day after driving for about a few weeks. i thought it was on their good and was just waiting to go get it welded up. clamps kinda suck so get it welded up eventually. it seals all the pipes so no leaks too! lol
and for more sound get a high flow cat. it does sound soo much better with high flow cat or no cat.
get a sawzall. it makes it sooo much easier to cut that pipe out.
the only other thing you gotta look out for is the bolts to the cat. those could be rusted out and hard to move.. so PB blaster them before hand.
and make sure you clamp those clamps down VERY tight. i had mine tight but the back muffler fell off one day after driving for about a few weeks. i thought it was on their good and was just waiting to go get it welded up. clamps kinda suck so get it welded up eventually. it seals all the pipes so no leaks too! lol
and for more sound get a high flow cat. it does sound soo much better with high flow cat or no cat.
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From: Brighton, CO
Car: '72 Chevy Nova
Engine: Solid roller 355
Transmission: TH350
Axle/Gears: 8.5" 10-bolt 3.73 Posi
"Just bought a Flowmaster Cat-back."
I'm sorry

In answer to your question, don't slip fit it, weld it. Less leaks, stronger.
I'm sorry


In answer to your question, don't slip fit it, weld it. Less leaks, stronger.
Thread Starter
Junior Member
Joined: May 2006
Posts: 98
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From: Sterling, VA
Car: 1987 Camaro IROC-Z
Engine: 350 5.7 TPI
would it really leak bad enough for me to fail emissions, because i gotta get that passed by the end of the month? And how much would the welding of the slip fits range in cost?
Supreme Member

Joined: Aug 2004
Posts: 1,214
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From: Norwich, CT
Car: '89 Trans AM/'88 GTA
Engine: (2) Tuned Port L98's
Originally Posted by Tobias05
should be good to go...86-91 3" single cat application right?
next on the list: hooker 2055's! highly recommend, look into it.
any pics of the z? I have a soft spot for 87's...
next on the list: hooker 2055's! highly recommend, look into it.
any pics of the z? I have a soft spot for 87's...
Sorry to interrupt,
I opted to go with a pair of Hedman 68481's, what's the
diffrence between the 2055's? and the 68481's?
I saw the charts that ThirdGen.org has posted, but all flows
looked fairly identical...
I went with the Hedman's because the quality, ease of install
and the performance, but I was just curious about the
Hooker 2055's
Thanks
-TPI
----------
Originally Posted by urbanhunter44
"Just bought a Flowmaster Cat-back."
I'm sorry

In answer to your question, don't slip fit it, weld it. Less leaks, stronger.
I'm sorry


In answer to your question, don't slip fit it, weld it. Less leaks, stronger.
Definately listen to waht he said
Last edited by TPI; Jun 17, 2006 at 06:05 PM. Reason: Automerged Doublepost
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From: Brighton, CO
Car: '72 Chevy Nova
Engine: Solid roller 355
Transmission: TH350
Axle/Gears: 8.5" 10-bolt 3.73 Posi
Originally Posted by Rosadoc-Z
would it really leak bad enough for me to fail emissions, because i gotta get that passed by the end of the month? And how much would the welding of the slip fits range in cost?
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Joined: May 2006
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From: Alloway Nj
Car: 85 Pontiac Trans Am
Engine: wouldnt you lilke to know??
Transmission: TH350 Built to the hilt
Axle/Gears: 4:10 Gears Moser Axle Auburn Posi
hey i dont know how good your local votech is but i know the one from where i just graduated from welded preety dern good ... i put on a flowmaster exhaust also they do the work for free around here as long as you buy the parts.... now if and when you have it done at a votech make sure you tell them to clamp your cat in (for easy removal) and weld the rest only untill you get through inspection then take out your cat and weld in a straght pipe..... thats what i did and its sounds great
Joined: Sep 2003
Posts: 25,895
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From: Pittsburgh PA
Car: 89 Iroc-z
Engine: 555 BBC Turbo
Transmission: TH400
Axle/Gears: MWC 9” 3.00
yes, i had my flowmaster clamped together for about a month.... and then had it welded. the guy charged me 100 bucks, which i thought was very high. but it was a nice job.
the damn muffler fell off one day while i was driving around. those clamps dont work well. so i decided to get it welded.
and just yesterday my new exhaust setup fell off cuz it was clamped... and waiting to be welded...left me stranded on the side of the road for over an hour while i tryed to get the muffler taken off so i could drive home. thank god i was near sears, and could get a wrench to take off the other clamp! lol
the damn muffler fell off one day while i was driving around. those clamps dont work well. so i decided to get it welded.
and just yesterday my new exhaust setup fell off cuz it was clamped... and waiting to be welded...left me stranded on the side of the road for over an hour while i tryed to get the muffler taken off so i could drive home. thank god i was near sears, and could get a wrench to take off the other clamp! lol
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From: Oakville, Ct
Car: 1991Firebird T/A
Engine: 350
Transmission: Modified Viper t-56
Axle/Gears: dana 44, 3.55
Originally Posted by urbanhunter44
"Just bought a Flowmaster Cat-back."
I'm sorry

I'm sorry


Thread Starter
Junior Member
Joined: May 2006
Posts: 98
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From: Sterling, VA
Car: 1987 Camaro IROC-Z
Engine: 350 5.7 TPI
i checked with two shops around here and they both told me the same thing. They cant weld the connections if the system is already installed. They wont be able to weld the top part of the exhaust.
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Joined: Jul 2001
Posts: 5,225
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From: Buffalo, NY
Car: 1988 IROC-Z
Engine: 427 SBC
Transmission: ProBuilt 700R4
Axle/Gears: Moser 12 Bolt / 3.73 TrueTrac
My whole exhaust has been clamped for the last 5 years. Nice and tight, never had a problem.
Joined: Sep 2003
Posts: 25,895
Likes: 429
From: Pittsburgh PA
Car: 89 Iroc-z
Engine: 555 BBC Turbo
Transmission: TH400
Axle/Gears: MWC 9” 3.00
well the exhaust will eventually have to be installed and welded... if they take out the pipe to weld it, how they gonna get it back in? one of the pieces has to be in there during the weld, probly the over the axle system. the pipe going into the muffler has to be welded up durin the install somehow.
i dont know how they did mine, but it was all welded up, all around the pipes.. they did a nice job but charged me 100 bucks... i thought that was very high
i dont know how they did mine, but it was all welded up, all around the pipes.. they did a nice job but charged me 100 bucks... i thought that was very high
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