Cat Back System ?
Thread Starter
Intermediate
Joined: Mar 2004
Posts: 33
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From: Victoria BC
Cat Back System ?
I just got an 85 coupe, my first vet! I would like to install a cat back system from either flowmaster, borla or magna flow. But now of these companies have a listing for the 85, they all start at 86. Was there a major design change between 85-86. or is it just something simple like the flange size at the cat?
Drifting
Joined: Jan 2002
Posts: 1,606
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From: Las Cruces NM
Re: Cat Back System ? (IRC)
The flange on 86's was a round 3" type. The cat bolts to the rear y-pipe and slip fits to the front.
On '85, the cat's openings are oval shaped and it bolts to both y-pipes.
It's not easy to just re-shape the opening on the rear y-pipe and have it seal properly. I don't know if anyone's done it, but I would check into getting an aftermarket front y-pipe(your 85 doesn't have pre-cats, so get one that's minus them from Mid America), a high flow cat, and a catback, all for the later years.
You'd notice a huge gain in performance by this, although it's not the cheapest way. The cool thing would be that you'd have the choice of what catback to bolt up. I don't think there's much difference in the manifolds on an 85 from an 86, so one of MAD's high flow front y-pipes should just bolt up.
I would check to make sure it'd work, this is just me talking out my behind and it's late at night, but I can't really think of a reason why it wouldn't.
Chris
On '85, the cat's openings are oval shaped and it bolts to both y-pipes.
It's not easy to just re-shape the opening on the rear y-pipe and have it seal properly. I don't know if anyone's done it, but I would check into getting an aftermarket front y-pipe(your 85 doesn't have pre-cats, so get one that's minus them from Mid America), a high flow cat, and a catback, all for the later years.
You'd notice a huge gain in performance by this, although it's not the cheapest way. The cool thing would be that you'd have the choice of what catback to bolt up. I don't think there's much difference in the manifolds on an 85 from an 86, so one of MAD's high flow front y-pipes should just bolt up.
I would check to make sure it'd work, this is just me talking out my behind and it's late at night, but I can't really think of a reason why it wouldn't.
Chris
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Re: Cat Back System ? (IRC)
Only because the catback attaches to the cat differently in 85, otherwise they fit.
I know that Power Effects made a small plate that lets their system fit, but they are also out-of-production at the moment.
You should be able to find a shop that'll just weld these on or make a plate that will adapt it yourself.
I know that Power Effects made a small plate that lets their system fit, but they are also out-of-production at the moment.
You should be able to find a shop that'll just weld these on or make a plate that will adapt it yourself.
Thread Starter
Intermediate
Joined: Mar 2004
Posts: 33
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From: Victoria BC
Re: Cat Back System ? (vader86)
Great news if its just the flange than no problem, I can do the fabrication work myself. I just wasn't sure if the mufflers were in the same spot and the angles for the rear y pipe were the same. Thanks for the help.
