stock exhaust removal

[SC UL8R1990]

My Dad has a 90 ZR-1, he wants to replace the stock exhaust with an aftermarket cat-back but before he takes the plunge he wants to make sure the stock exhaust can be removed without cutting. he wants to make sure the factory exhaust just unbolts so he can put it back to stock when he likes.

can anyone confirm that the factory exhaust simply unbolts?

[Dynomite]

Originally Posted by SC UL8R1990

My Dad has a 90 ZR-1, he wants to replace the stock exhaust with an aftermarket cat-back but before he takes the plunge he wants to make sure the stock exhaust can be removed without cutting. he wants to make sure the factory exhaust just unbolts so he can put it back to stock when he likes.

can anyone confirm that the factory exhaust simply unbolts?

Are you talking about the exhaust "pipes" or exhaust manifold? Here is a picture of my Exhaust System for a 91'

On a 91' the CATS are welded to the exhaust manifolds and the mufflers are welded to the exhaust pipes. There is only one joint that is bolted with a flange between the CATS and the "pipes" on each side (you can see the flanges in the picture). The exhaust hangers are all bolted (two on the twin pipes and one each on the exhaust mufflers).



I am sure a 90' exhaust unbolts just like my 91'

The BIG problem in removing the exhaust manifold is getting wrenches in such a small space

Removing the original exhaust system is a lot easier if you have a 3/8 inch universal, a set of flex metric ratchet wrenches, and a set of 3/8 inch wobble extensions

A set of 3/8 inch metric sockets and 3/8 inch socket wrench is obvious

I use the wobble extensions on almost everything.

[tuband]

The factory exhaust is a simple bolt/unbolt. No need to cut.

• Exhaust flange bolts (right & left sides)
• 2 hanger bolts in front of resonator
• 2 hanger bolts behind resonator
• 1 hanger bolt each muffler

Aftermarket exhausts normally bolt up to the stock manifold with minimal or no fabrication. If you're after a freer flowing exhaust the next step up might be to use a stock 95 ZR-1 cat back system ... it flows better than stock 90. Others to consider include Corsa, Borla, B&B, Magnaflow.

If you want even more performance/sound/free flow then you need to change the stock manifolds out for a good set of headers and high flow cats (or no cats).

Be forewarned ... changing the exhaust is one of the first mods one does to a Z. Mod fever is REAL and very contagious.

[SC UL8R1990]

thanks for the quick replies, we are just doing the catback. dont want to venture too far from stock.

[Jim Nolan]

I'll second that contagious part. I started with the catback exaust, then I sent off the plenum and IH's for porting, then a eprom reflash, then when that wasn't enough I then went for the SGC 475 package with headers and 3:91 rear. Looking back with what I spent I should have gone with the 368 from the start. The after market exaust took me about 3 hours from start to finish, working by-myself, between beers. Good luck on the addition. Hmmmmmmmmm 415.

[Jagdpanzer]

Check this out
http://zr1netregistry.com/Old_Proj/old_proj8.htm

[SC UL8R1990]

Originally Posted by Jim Nolan

I'll second that contagious part. I started with the catback exaust, then I sent off the plenum and IH's for porting, then a eprom reflash, then when that wasn't enough I then went for the SGC 475 package with headers and 3:91 rear. Looking back with what I spent I should have gone with the 368 from the start. The after market exaust took me about 3 hours from start to finish, working by-myself, between beers. Good luck on the addition. Hmmmmmmmmm 415.

yea, he has a few vehicles, the ZR is one he wont be modding too much. its got 12k orig miles on it.....still on the original factory tires (which we are keeping but replacing for safety reasons).