New exhaust - what to buy? - ZR-1 Net Registry Forums

Norwegianmopar · 08-02-2018

Seems our cats are shot now (sparking/knocking sound from the underside when stepping on it and reduced power above 4000 rpm), and the front muffler has been welded, so we are considering a new exhaust system.

What are you guys recommending? Where to buy?

Does installing headers mean the engine needs to be pulled to get them on? (Someone told me so...)

The car is stock with 4:10 gears and Haibeck chip.

All tips and advice are welcomed [emoji106]20180707_122507.jpg 20180707_122457.jpg 20180707_122413.jpg

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dredgeguy · 08-02-2018

Have enjoyed your photos. You cannot go wrong with Stainless Works headers with their high flow cats and a Corsa exhaust. Great sound at idle and when above 3000 RPM everybody knows you came to the party to play. No drone on the highway. Not the least expensive but worth the investment.

-=Jeff=- · 08-02-2018

yes, Corsa is nice.. But as stated it is really heard at WOT.. if it was not as loud as it is, I will still have it on my car.. I really liked the no drone aspect of it

Ccmano · 08-02-2018

If the cats are coming apart internally, do not run the car! Fine bits of the ceramic will be drawn into the cylinders and will eat up the cylinder walls. If you research on this forum you can find much more on the catalyst issue. I believe AB26 has written considerably on this.

And, no the engine does not have to be removed to install headers.

H

GOLDCYLON · 08-02-2018

X2 for Corsa

Norwegianmopar · 08-02-2018

Quote:

Originally Posted by Ccmano

If the cats are coming apart internally, do not run the car! Fine bits of the ceramic will be drawn into the cylinders and will eat up the cylinder walls. If you research on this forum you can find much more on the catalyst issue. I believe AB26 has written considerably on this.

And, no the engine does not have to be removed to install headers.

H

Should there be a warning lamp coming on if it's the cats..? I have no lamps on at all.

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Ccmano · 08-02-2018

Quote:

Originally Posted by Norwegianmopar

Should there be a warning lamp coming on if it's the cats..? I have no lamps on at all.

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No warning lamp, your dealing with 1980’s technology. These cars only have one O2 sensor per side and it’s ahead of the cat. It can’t tell if the cat is bad. Later technology put O2’s on either side of the cat and could monitor cat function. But not on our cars.
H

rush91 · 08-02-2018

It looks as if you have aftermarket mufflers. If that's the case, I'd cut out the resonator and replace it with an X-pipe with the headers...Nothing wrong with the stock 2.75 exhaust tubing.

Norwegianmopar · 08-02-2018

Quote:

Originally Posted by rush91

It looks as if you have aftermarket mufflers. If that's the case, I'd cut out the resonator and replace it with an X-pipe with the headers...Nothing wrong with the stock 2.75 exhaust tubing.

It has Borla exhaust.

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Ccmano · 08-02-2018

Here’s one of the threads by AB26 (Jerry Downey) in the subject of cat failure. Note that in the thread it’s confirmed by Mark Hibeck and even Graham Behan one of the original GM/Lotus engineers. It’s one of the reasons the later cat setup was changed on the 93-95 Cars.

http://www.zr1.net/forum/showthread....light=Catalyst
H

08-02-2018	#1
Norwegianmopar Join Date: Mar 2018 Location: Norway Posts: 346	New exhaust - what to buy? Seems our cats are shot now (sparking/knocking sound from the underside when stepping on it and reduced power above 4000 rpm), and the front muffler has been welded, so we are considering a new exhaust system. What are you guys recommending? Where to buy? Does installing headers mean the engine needs to be pulled to get them on? (Someone told me so...) The car is stock with 4:10 gears and Haibeck chip. All tips and advice are welcomed [emoji106]20180707_122507.jpg 20180707_122457.jpg 20180707_122413.jpg Sent from my SM-G955F using ZR-1 Net Registry mobile app __________________ Roy Martin 1994 ZR-1 #112 Admiral Blue/Black Dana 4:10 Aluminum flywheel Corsa exhaust Watson headers Haibeck chip 470 HP/399 RWHP 1991 ZR-1 #400 White/Red (SOLD) Dana 4:10 Powder coated engine Haibeck performance chip Borla exhaust

08-02-2018	#2
dredgeguy Join Date: Aug 2012 Location: Ellicott City, MD Posts: 1,720	Re: New exhaust - what to buy? Have enjoyed your photos. You cannot go wrong with Stainless Works headers with their high flow cats and a Corsa exhaust. Great sound at idle and when above 3000 RPM everybody knows you came to the party to play. No drone on the highway. Not the least expensive but worth the investment. __________________ Charlie __________ Dredgeguy WAZOO Member 1992 Bright Red/Black ZR1 #246 Dana 4:10 gears Polished LT5 by Haibeck Polished Fikse FM5's with Michelin Pilot Sport 2 Stainless Works headers and cats with Corsa

08-02-2018	#3
-=Jeff=- Join Date: Jul 2007 Location: Bartlett, IL Posts: 7,157	Re: New exhaust - what to buy? yes, Corsa is nice.. But as stated it is really heard at WOT.. if it was not as loud as it is, I will still have it on my car.. I really liked the no drone aspect of it __________________ 1990 Corvette ZR-1 #1051 Watson Headers (2" Primary) - Flowmaster Cats - Borla Catback Late Model IH - Plenum Coilovers - 4.10s Shelby Series 1 - Wilwood Brakes Custom Interior NCM Lifetime Member #978

08-02-2018	#4
Ccmano Join Date: Jun 2006 Location: Sparks, NV Posts: 2,843	Re: New exhaust - what to buy? If the cats are coming apart internally, do not run the car! Fine bits of the ceramic will be drawn into the cylinders and will eat up the cylinder walls. If you research on this forum you can find much more on the catalyst issue. I believe AB26 has written considerably on this. And, no the engine does not have to be removed to install headers. H Last edited by Ccmano; 08-02-2018 at 09:55 AM.

08-02-2018	#5
GOLDCYLON Join Date: May 2007 Location: Peoria, AZ Posts: 9,120	Re: New exhaust - what to buy? X2 for Corsa __________________ GOLDCYLON - 91 ZR-1 #2014 GOLDCYLON - 90 ZR-1 #2794, 4L60e (Formerly Schrade's) GOLDCYLON - 11 CTS-V Arizona State Director 91 WHITE/BLACK #2014. 380 P&P&PCed,Ported Heads, Jeal Long tubes, Corsa Exhaust/FIKSE FM-5s /LED TLs, LED Headlights, Front Wilwood 6 piston narrowlite calipers and rear Wilwood caliper street shop mod,CNCed Coolant Pipes,TPI Cvr,Filter cover,Stainless Bolts, DRM/DOM PROM /ZFDOC mod build #102,DRLs,BMAD with stainless Debris Screen,Coplan Air Blaster, Pioneer APP Radio 4,Brey-Krause HB,Sub Bar,Fire extinguisher seat mount,DRM Coilovers,LEDs everywhere,Compass mirror (orange),V1 DIC hidden display, Homelink sun visor, Carbon Fiber top x3 and APSIS Carbon Fiber interior, APSIS CF Steering Wheel/NAPA Leather, Banski trailing arms, Guldstrand front suspension,urethane bushings from Prothane (total suspension) ZFDoc drive shaft safety loop, raptor shift light (orange),AO engineering louver front plate, Console seat cushion, 96CE seats with black custom Sheepskins, ss billet catch can,Viper remote entry/alarm,Cragar Rear Louvers,LED side louver lights, Dewitts Radiator with SPAL fans and a Woods 160 T-Stat 90 RED/BLACK #2794. 4L60e Automatic Stage V by RPM Transmission, TCI Dedicated TCM, OBX Stainless Headers, Corsa Exhaust, SAN Secondaries and Haibeck PROM, Exotic Muscle Coil overs, LED Interior Lights, LED Tail Lights, LED Headlights, 94 Sport seats with black custom Sheepskins , Cragar rear louvers, GS Front calipers, Banski Trailing arms, APSIS Carbon Fiber steering wheel, Front and Rear Baer Eradispeeds, DRLs, Guldstrand front suspension,urethane bushings from Prothane (total suspension), Dewitt's Raditor with Dual SPAL fans and a Haibeck 170 T-Stat 11 RED/GREY CTS-V

08-02-2018	#8
rush91 Join Date: Feb 2016 Location: Carterville Illinois Posts: 854	Re: New exhaust - what to buy? It looks as if you have aftermarket mufflers. If that's the case, I'd cut out the resonator and replace it with an X-pipe with the headers...Nothing wrong with the stock 2.75 exhaust tubing.

08-02-2018	#10
Ccmano Join Date: Jun 2006 Location: Sparks, NV Posts: 2,843	Re: New exhaust - what to buy? Here’s one of the threads by AB26 (Jerry Downey) in the subject of cat failure. Note that in the thread it’s confirmed by Mark Hibeck and even Graham Behan one of the original GM/Lotus engineers. It’s one of the reasons the later cat setup was changed on the 93-95 Cars. http://www.zr1.net/forum/showthread....light=Catalyst H