Starting the mods - ZR-1 Net Registry Forums

Subfixer · 12-31-2018

First mod I'd like to attack will be headers, so here are the questions...

Will Stainless Works Headers/Cats bolt up to the stock exhaust?
I want to keep the nice "quiet" stock exhaust.

I'm pretty good with a wrench, but is header install a one man job?

I thought I read somewhere that there are 2 different size resonator internal ID's.

Which years had the larger internal ID?

Mark's chip is also in the plan, but the top end porting will have to wait until next year. Maybe by that time I'll have saved enough for a 415...

Enough questions for now.

secondchance · 01-01-2019

SS works header will bot up to stock exhaust.

Can be installed by one person. Removing and reinstalling exhaust may be challenging.

I think 93 and later Zs have larger resonator internal diameter.

Ccmano · 01-01-2019

The toughest part of the header job is getting the OEM exhaust manifolds and associated emissions hardware out. I’ve done several by myself. It’s tight especially on the passenger side. If your patient and take your time is pretty straight forward. Removing the engine mount nuts and K members and lifting the engine slightly helps a lot. Inspect the engine mounts while your in there dollars to doughnuts one or both are broken. The 90-92 exhausts had a restricted resonator. If your keeping the stock exhaust swap that out for a later one, x pipe or Dynomax Ultraflow Welded X resonator. Exhaust system fabrication to some degree is unavoidable when your doing headers.
Have fun.
H

Vette73 · 01-01-2019

A 415 build will cost more than what you paid for the car....I think I saw that Vettes Drs.wanted like $22,000 for a ZR-1 build ...Better off contacting Pete, Haibeck or evolution motorsports if you want to build HP...

Ccmano · 01-01-2019

If I had the bucks I’d be doing Pete’s 391...
H

Subfixer · 01-01-2019

Quote:

Originally Posted by Ccmano

The toughest part of the header job is getting the OEM exhaust manifolds and associated emissions hardware out. I’ve done several by myself. It’s tight especially on the passenger side. If your patient and take your time is pretty straight forward. Removing the engine mount nuts and K members and lifting the engine slightly helps a lot. Inspect the engine mounts while your in there dollars to doughnuts one or both are broken. The 90-92 exhausts had a restricted resonator. If your keeping the stock exhaust swap that out for a later one, x pipe or Dynomax Ultraflow Welded X resonator. Exhaust system fabrication to some degree is unavoidable when your doing headers.
Have fun.
H

Everything is tight in there...…..
What other emissions hardware gets removed? AIR plumbing? Can I keep that stuff?
I've been looking for a stock replacement 93-95 resonator, but they seem to be non-obtainable. Hopefully something like the Dynomax will keep the "drone" out.

-=Jeff=- · 01-01-2019

when do you need the 93-95 resonator. I am quite sure I still have one, however I will not be able to get at it for a while.. due to a medical issue with my right foot..

Ccmano · 01-01-2019

It’s really the air injection plumbing mostly. It runs under the engine to the passenger side. You can also remove the air pump in the driver side well next to the radiator. Good spot for an oil catch can when the air pump is out. I think Dominic (Xfirez51) is (or was) running the Dynomax resonator. Keep in mind stock pipes are 2.75” diameter, an unusual size. Most aftermarket exhaust items are either 2.5 or 3.0”s. Requires some adaptation. Unless your good at welding it’s best to let an exhaust shop do it. I’m a terrible welder. I usually cut all the pieces, fit everything together, spot weld it in place and let a shop do the final welding.
H

EvanZR1 · 01-01-2019

I second the vote for a 391 from Pete. Very, very happy with mine, and the best $/HP you can get from an engine build. Honestly though, if your engine doesn’t need a rebuild, your best route is headers and ported top end.

Subfixer · 01-01-2019

Quote:

Originally Posted by -=Jeff=-

when do you need the 93-95 resonator. I am quite sure I still have one, however I will not be able to get at it for a while.. due to a medical issue with my right foot..

Will not be needed until sometime in the spring. Unheated garage up here, so I'll wait for milder weather before taking things apart.

12-31-2018	#1
Subfixer Join Date: Sep 2018 Location: Groton, CT Posts: 384	Starting the mods First mod I'd like to attack will be headers, so here are the questions... Will Stainless Works Headers/Cats bolt up to the stock exhaust? I want to keep the nice "quiet" stock exhaust. I'm pretty good with a wrench, but is header install a one man job? I thought I read somewhere that there are 2 different size resonator internal ID's. Which years had the larger internal ID? Mark's chip is also in the plan, but the top end porting will have to wait until next year. Maybe by that time I'll have saved enough for a 415... Enough questions for now. __________________ 1992 ZR1 #442, 2 tops, White, White, Haibeck 415, 3.90 gear, Coilovers 2018 Audi RS5, 2.9 V6 Twin Turbo, Auto, Black, Black 2021 Audi Q3, 2.0T, 8 spd Tiptronic, Navarro Blue metallic, Pearl Beige

01-01-2019	#2
secondchance Join Date: Aug 2006 Location: McLean, VA Posts: 3,723	Re: Starting the mods SS works header will bot up to stock exhaust. Can be installed by one person. Removing and reinstalling exhaust may be challenging. I think 93 and later Zs have larger resonator internal diameter.

01-01-2019	#3
Ccmano Join Date: Jun 2006 Location: Sparks, NV Posts: 2,852	Re: Starting the mods The toughest part of the header job is getting the OEM exhaust manifolds and associated emissions hardware out. I’ve done several by myself. It’s tight especially on the passenger side. If your patient and take your time is pretty straight forward. Removing the engine mount nuts and K members and lifting the engine slightly helps a lot. Inspect the engine mounts while your in there dollars to doughnuts one or both are broken. The 90-92 exhausts had a restricted resonator. If your keeping the stock exhaust swap that out for a later one, x pipe or Dynomax Ultraflow Welded X resonator. Exhaust system fabrication to some degree is unavoidable when your doing headers. Have fun. H __________________ 90'ZR-1 #1461 Red/Black Ported Intake, Degreed Cams, OBX Headers & Exhaust, Fidanza FW, Secondary Delete, Custom tune, C6 GS Wheels. Sold 08 C6 Z51 Crystal Red Metallic Sold Vararam Intake, Tune, Sold 05 C6 Z51 Red/Black Sold 90'ZR-1 #1723 Black/Gray Sold but not forgotten 91' Z51 L98 White Vert. My First, you always remember your first. Sold. Last edited by Ccmano; 01-01-2019 at 12:11 PM.

01-01-2019	#4
Vette73 Join Date: Nov 2014 Location: Brooklyn ny Posts: 1,045	Re: Starting the mods A 415 build will cost more than what you paid for the car....I think I saw that Vettes Drs.wanted like $22,000 for a ZR-1 build ...Better off contacting Pete, Haibeck or evolution motorsports if you want to build HP...

01-01-2019	#5
Ccmano Join Date: Jun 2006 Location: Sparks, NV Posts: 2,852	Re: Starting the mods If I had the bucks I’d be doing Pete’s 391... H __________________ 90'ZR-1 #1461 Red/Black Ported Intake, Degreed Cams, OBX Headers & Exhaust, Fidanza FW, Secondary Delete, Custom tune, C6 GS Wheels. Sold 08 C6 Z51 Crystal Red Metallic Sold Vararam Intake, Tune, Sold 05 C6 Z51 Red/Black Sold 90'ZR-1 #1723 Black/Gray Sold but not forgotten 91' Z51 L98 White Vert. My First, you always remember your first. Sold.

01-01-2019	#7
-=Jeff=- Join Date: Jul 2007 Location: Bartlett, IL Posts: 7,169	Re: Starting the mods when do you need the 93-95 resonator. I am quite sure I still have one, however I will not be able to get at it for a while.. due to a medical issue with my right foot.. __________________ 1990 Corvette ZR-1 #1051 Watson Headers (2" Primary) - Flowmaster Cats - Borla Catback Late Model IH - Plenum Coilovers - 4.10s Custom Interior NCM Lifetime Member #978

01-01-2019	#8
Ccmano Join Date: Jun 2006 Location: Sparks, NV Posts: 2,852	Re: Starting the mods It’s really the air injection plumbing mostly. It runs under the engine to the passenger side. You can also remove the air pump in the driver side well next to the radiator. Good spot for an oil catch can when the air pump is out. I think Dominic (Xfirez51) is (or was) running the Dynomax resonator. Keep in mind stock pipes are 2.75” diameter, an unusual size. Most aftermarket exhaust items are either 2.5 or 3.0”s. Requires some adaptation. Unless your good at welding it’s best to let an exhaust shop do it. I’m a terrible welder. I usually cut all the pieces, fit everything together, spot weld it in place and let a shop do the final welding. H __________________ 90'ZR-1 #1461 Red/Black Ported Intake, Degreed Cams, OBX Headers & Exhaust, Fidanza FW, Secondary Delete, Custom tune, C6 GS Wheels. Sold 08 C6 Z51 Crystal Red Metallic Sold Vararam Intake, Tune, Sold 05 C6 Z51 Red/Black Sold 90'ZR-1 #1723 Black/Gray Sold but not forgotten 91' Z51 L98 White Vert. My First, you always remember your first. Sold.

01-01-2019	#9
EvanZR1 Join Date: Nov 2010 Location: Omaha Posts: 403	Re: Starting the mods I second the vote for a 391 from Pete. Very, very happy with mine, and the best $/HP you can get from an engine build. Honestly though, if your engine doesn’t need a rebuild, your best route is headers and ported top end. __________________ Evan 2024 Z06 SOLD - 1991 Admiral Blue ZR-1 SOLD - 2012 Carlisle Blue Metallic ZR1 - 800HP SOLD - Steel Blue 91 391cid ZR-1 #391 SOLD - Black 91 ZR-1