afgun

Anyone ever install Mac exhaust on a third gen? I have a few questions...

1) The Mac headers TF8690 say they include a new starter tube for catalytic. However, my "second hand but unused" headers didn't have that. Anybody know if it's the same as a factory starter tube for single catalyst?

2) I replaced the dual catalyst exhaust on my GTA with single catalyst. The bracket to hang the cat appears different between single and dual catalyst cars. I'm guessing that p/n 14089475 is the appropriate one, from <A HREF="http://www.metzcon.com/fbodymanual/images/3-161.jpg">the illustrated f-body parts</A>. That page lists two different parts for a/t vs m/t for 90-92. Any idea why? Also that site has a description that has a different part number for 89 LB9 vs. TPI dual cat cars. Did they get different exhausts?

3) Anyone hang Mac TKC691 cat-back before? There are rubber isolators and straps that attach the tailpipes to the car somehow. I'm wondering if I'm supposed to use one of the body bolts that is already on the car, or drill a new hole to mount them. Unfortunately, my new-from-the-manufacturer exhaust didn't come with instructions.

Thanks!!

--andrew

MRZ28HO

1) Is this a 4-bolt or 2-bolt cat you want to use? Either way I doubt it will work. Just ask MAC for a new one (macperformance.com)

2) I can't help here

3) I used existing bolts from the vehicle on my 4th gen, I would image that is the intention. Otherwise, the tips are going to be "dancing" while you drive.

------------------
George P. Lara
1984 Z28
2001 SS #0391
SCCA, SCFB, SC3GFB

afgun

Mac is sending me a new starter tube. They rock!

I'm going to buy the single cat transmission bracket and see if that fits.

For the rear, my stock exhaust didn't have rear hangers. Just the rubber slip-in mount on the passenger side and rubber bolt-on strap on the driver side.

It looks like I could possibly use bolts that are already holding the rear bumper on. I'm going to experiment with that tonight.

afgun

Ok, looks like I misinterpreted what a "starter tube for catalytic" is.

I need the AIR pipe from the air diverter valve to the catalytic converter for a single cat car. Anybody have one they want to part with?

I also need the catalytic converter hanger for single catalyst. The one that bolts to the transmission mount for automatic transmission. Anybody have one of these too?

MRZ28HO

GM should still have this part available (Air Tube from diverter valve to catalytic converter). I can't recall the part number, but back in '94 I had to purchase one. IIRC it was ~$80 and pre-bent.

afgun

Unfortunately there's none in the midwest and same with the hanger bracket. It'd cost me wayyyy to much to have GM ship one around the country, so I'm trolling for used ones

--andrew

afgun

Well, thanks to a generous reader, I've got the cat hanger on the way. Still need the AIR tube for single cat car...

Anyways, I had to move the car today so I tightened up everything and took it off the jackstands and fired it up. Man it sounds good! I think that when I broke the #4 spark plug and replaced it (it was coated in gas!) I fixed a problem that I'd been chasing for awhile...

So I just had to take it for a spin around the neighborhood. It runs SO much better than it did before with the stock manifolds and flowmaster cat-back. And it sounds awesome. It's like a new car. It runs a lot more like I expected a car with this level of mods to run

Just had to share. Now back to your regularly scheduled message board.

--andrew