Hajile08

I'm looking for a new catback exhaust for my dual cat car. It's an all original '90 Iroc 5.7 TPI except for one repaint and the muffler shop catback exhaust it already has on it. I'm assuming the previous owner was trying to keep the original sound as much as possible because he went with a 2" mid pipe and tailpipes with a Flowmaster muffler. I want to keep the car as original possible for now except I want to go with a 3" catback to get a better sounding car. I do not want to remove the dual cats. This thing is too quiet like it is. I can just barely hear the exhaust while driving. From all I've learned reading through posts on this site I know I need to go with mandrel bent 3" pipes, and that I do not believe there is a bolt on catback to fit the dual cat cars. What are my best options? Have a shop modify a catback for a single cat car to fit mine or is there one to fit that I haven't found? Thanks

thtanner

iTrader: (1)

Mine has a 3" flowmaster catback off the dual cats. Theyre magnaflow high-flow cats (50 state). It looks like it was a kit to me, not exactly a lot of custom fab work.

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Hajile08

That sounds great. That's what I want mine to sound like. I just can't seem to find a kit that looks like it will fit because all of them have a slight bend right before the flange and mine needs to be straight all the way to the flange that connects to the y pipe.

thtanner

iTrader: (1)

If that's all, you can have a muffler shop cut where it's a bend is and weld in a 3" pipe there.

You can also hack off the bend and use some strait pipe and clamp it together, but welding is always preferable.

Hajile08

I sure was hoping to find a kit to fit without having to get it modified. I found a post where Flowmaster used to make a kit to bolt straight to dual cat cars but it has been discontinued.

thtanner

iTrader: (1)

Could be what I have then, I don't see any points where mine was cut and adjusted towards the Y.

Hajile08

Well I finally got to get under my car and get a better look at it. It doesn't have a flange at all, the two pipes are just clamped together. It looks like the outlet on the y pipe is also 2.25" so I guess I have to look at getting it replaced also. I guess I'll just have to take it to the muffler shop and see what they can do with it. I just don't want to go with shop bent pipes.

1fast91

Which flomaster series muffler is that? I like the way it sounds.
I wasn't sure if I should get rid of the cats but that sounds nice.

TTOP350

iTrader: (8)

Magnaflow or dynomaxx still have anything???

paul_huryk

Magnaflow only makes one system for the 3rd gens - a single cat exhaust. At least you can use it for both 2.25" and 3" cats.

As far as I know, no one makes a dual cat exhaust now - GM did not make the system the same for every year it was offered and it is too much of a PITA for any manufacturer to make specific systems for all the cars. You will have to fabricate a dual cat system out of a single cat one.

Magnaflow does offer a dual cat y-pipe with cats attached and may be the only manufacturer to do so today. I tell people just to convert to a single cat system if their state allows it (CA people are screwed as usual).

BradS(IL)

I bought a NOS N10 just to have as a back up because they are super hard to find, especially new ones. Don't need it now but someone will someday!

BradS(IL)

But I still would like to find a new factory cat- back system to replace my Magnaflow system (little too loud)

VincentZ28

iTrader: (2)

Keep the dual cats. The dual cat cars made 5hp over the single cat cars. Just get a flowmaster y-pipe and Magnaflow cat-back exhaust system. You will make more power this route and still be quiet. Throw some Dyno Don's headers on it and the power will be up to 280hp compared to stock 245hp. Your car lost hp with that 2in mid-pipe.