CSP Headers and 1700hp gen2 cats

Camaro1973 · 06-05-2021, 06:14 PM

Well, most of you know my dilemma. 800rwhp, hate raw smell of no cats, blew out 2 sets of gesi green cats so far.

Well it’s going under the knife again. Will be removing the kooks 2” headers and replacing them with the CSP 2” Headers with the new 1700hp (850 per bank gesi gen 2 cats). I don’t know anyone else yet in the area that has a custom fit yet besides CSP to headers and the new gen 2 cats yet. Might be possible to fit them
To my kooks by welding, but not sure actual fitment as they are larger.

In any case it’s going in the week of the 21st this month so I’ll keep updating to see how these ones hold up.

I think the issue TBH with the original GESI cats is there just not big enough, and the force from 800hp and FI is just killing them.

Even compared to the stock cats, they are smaller. We shall see.

I’ve got a graveyard of exhaust parts in my garage and more coming soon. I may advertise a rummage sale soon

cmitchell17 · 06-05-2021, 06:30 PM

Quote:

Originally Posted by Camaro1973

Well, most of you know my dilemma. 800rwhp, hate raw smell of no cats, blew out 2 sets of gesi green cats so far.

Well it’s going under the knife again. Will be removing the kooks 2” headers and replacing them with the CSP 2” Headers with the new 1700hp (850 per bank gesi gen 2 cats). I don’t know anyone else yet in the area that has a custom fit yet besides CSP to headers and the new gen 2 cats yet. Might be possible to fit them
To my kooks by welding, but not sure actual fitment as they are larger.

In any case it’s going in the week of the 21st this month so I’ll keep updating to see how these ones hold up.

I think the issue TBH with the original GESI cats is there just not big enough, and the force from 800hp and FI is just killing them.

Even compared to the stock cats, they are smaller. We shall see.

I’ve got a graveyard of exhaust parts in my garage and more coming soon. I may advertise a rummage sale soon

I was always surprised how small they were too, but makes sense, the smaller, the less material, the cheaper they are. They don't have to meet any emission standard so now reason for more catalyst material.

I really want to put my stock exhaust manifolds back on and try to adapt the GESI cats to them, I just feel like it would be extremely difficult to get the bends right to get good fitment.

Alain · 06-05-2021, 06:46 PM

Quote:

Originally Posted by Camaro1973

Well, most of you know my dilemma. 800rwhp, hate raw smell of no cats, blew out 2 sets of gesi green cats so far.

Well it’s going under the knife again. Will be removing the kooks 2” headers and replacing them with the CSP 2” Headers with the new 1700hp (850 per bank gesi gen 2 cats). I don’t know anyone else yet in the area that has a custom fit yet besides CSP to headers and the new gen 2 cats yet. Might be possible to fit them
To my kooks by welding, but not sure actual fitment as they are larger.

In any case it’s going in the week of the 21st this month so I’ll keep updating to see how these ones hold up.

I think the issue TBH with the original GESI cats is there just not big enough, and the force from 800hp and FI is just killing them.

Even compared to the stock cats, they are smaller. We shall see.

I’ve got a graveyard of exhaust parts in my garage and more coming soon. I may advertise a rummage sale soon

Good luck man.

Chrome383Z · 06-05-2021, 06:52 PM

I ordered the CSP headers with ultra cats (preorder), hopefully get them in soon. Overkill for now but planning 2650 in the future.

swisstyphoon · 06-05-2021, 06:52 PM

Quote:

Originally Posted by cmitchell17

I was always surprised how small they were too, but makes sense, the smaller, the less material, the cheaper they are. They don't have to meet any emission standard so now reason for more catalyst material.

I really want to put my stock exhaust manifolds back on and try to adapt the GESI cats to them, I just feel like it would be extremely difficult to get the bends right to get good fitment.

This is exactly what I did.
We have really strict emission laws, so the cats had to look factory in my case. So I welded the Gesi Gen2 cats in the stock housing and replaced the bottle neck downpipes with larger diameter pipe bends.

Camaro1973 · 06-05-2021, 07:43 PM

Quote:

Originally Posted by swisstyphoon

This is exactly what I did.
We have really strict emission laws, so the cats had to look factory in my case. So I welded the Gesi Gen2 cats in the stock housing and replaced the bottle neck downpipes with larger diameter pipe bends.

This is a really nice job bud.... Wont even be able to tell probably its aftermarket. Nice one.

Joshinator99 · 06-05-2021, 08:17 PM

Quote:

Originally Posted by Camaro1973

This is a really nice job bud.... Wont even be able to tell probably its aftermarket. Nice one.

Agreed. That came out fantastic!

*radz28* · 06-07-2021, 08:05 AM

That cat-re-piping is exactly what I have been thinking about trying to do.

KingLT1 · 06-07-2021, 08:14 AM

Nice work...Somebody needs to start selling those!

FoundNemo · 06-07-2021, 09:15 AM

I would 100% be in for a re-piped cat section with Gesi cats!

Revalot · 06-07-2021, 03:25 PM

Great Welds !

gtfoxy · 06-07-2021, 05:49 PM

Quote:

Originally Posted by swisstyphoon

This is exactly what I did.
We have really strict emission laws, so the cats had to look factory in my case. So I welded the Gesi Gen2 cats in the stock housing and replaced the bottle neck downpipes with larger diameter pipe bends.

Puuuurdy!

Mind sharing your TIG set-up?

cmitchell17 · 06-07-2021, 06:31 PM

So it looks like you completely cut the ends of the GESI cats and just welded the circular portion of the GESI cats back to the stock cats end? Is that correct?

I really want to attempt this, I just feel like I would fail miserably. My plan would be to cut the stock exhaust to the downpipe portion and bolt it to the car, then try to fabricate a holder/jig while under the car. Problem is I know this would be a dumb idea trying to do it, I've already made plenty of scars on my arm from burned slag hitting them while on my back under a car/truck trying to weld exhaust. I would need a lift for this.

I would gladly pay you and I'm sure there are a lot of other here too that would to make a setup like this.

One really big question I have is how is the sound quality? particularly how is the radiated non-exhaust noise? Is it similar to stock? I am talking about the ticking and other noise that is radiated from the exhaust itself and not actually the exhaust sound that comes from the end of the pipe.

cmitchell17 · 06-07-2021, 06:34 PM

Now that I think about it, if the GESI cats and the stock cats are similar in circular diameter, and if I didn't care about having the supposed stock downpipe bottleneck/restriction then it seems like it shouldn't be too difficult to cut out just the circular section, which it looks like you did, and just cut the circular section out of the GESI cats and weld them back in.

06-05-2021, 06:14 PM	#1
Camaro1973 Drives: 2019 ZL1 Join Date: Mar 2019 Location: NJ Posts: 1,534	CSP Headers and 1700hp gen2 cats Well, most of you know my dilemma. 800rwhp, hate raw smell of no cats, blew out 2 sets of gesi green cats so far. Well it’s going under the knife again. Will be removing the kooks 2” headers and replacing them with the CSP 2” Headers with the new 1700hp (850 per bank gesi gen 2 cats). I don’t know anyone else yet in the area that has a custom fit yet besides CSP to headers and the new gen 2 cats yet. Might be possible to fit them To my kooks by welding, but not sure actual fitment as they are larger. In any case it’s going in the week of the 21st this month so I’ll keep updating to see how these ones hold up. I think the issue TBH with the original GESI cats is there just not big enough, and the force from 800hp and FI is just killing them. Even compared to the stock cats, they are smaller. We shall see. I’ve got a graveyard of exhaust parts in my garage and more coming soon. I may advertise a rummage sale soon __________________ 928rwhp - 93 \| 1040rwhp/898rwrq - E65 SAE LME 377 LT4 Short Block \| Magnuson 2650 80mm upper w/13% lower (9.06) \| DSX Lid & Valve Covers \| CSP Custom Cam w/32% fuel lobe \| CID Heads \| NW 103mm TB \| Roto Fab Big Gulp \| CSP 2" Headers w/Green GESI Gen 2 Cats \| Borla 3" Full Cat Back w/ S-Type\| Mighty Mouse Wild Catch Can\| Custom Holley Low side Fuel system\| TooHigh PSI Port Injection w/Holley Controller \| Forced Inductions Interchiller w/2 gallon fender tank \| TK Performance built 10L90

06-05-2021, 06:52 PM	#4
Chrome383Z Drives: 2019 Camaro 2SS Join Date: Aug 2020 Location: McCordsville, Indiana Posts: 621	I ordered the CSP headers with ultra cats (preorder), hopefully get them in soon. Overkill for now but planning 2650 in the future. __________________ 2019 Shock 2SS A10. 2650@10psi/LPE HPFP/XDI+30/LT4 LPFP+JMS/Soler 95mm/Rotofab, E65, CSP 2” Headers/GESI GenII Cats. MM Wild/GM SG3 suspension/1LE Brakes, Velgen VF5 Wheels/GY SC3. JRE Tuned.

06-07-2021, 08:05 AM	#8
radz28 Petro-sexual Drives: Ultra-Grin Join Date: Oct 2006 Location: Crazy Coast Posts: 15,188 View My Garage	That cat-re-piping is exactly what I have been thinking about trying to do. __________________ '20 ZL1 Black "Fury" A10, PDR, Exposed CF Extractor Magnuson Magnum DI TVS2650R // RFBG // Soler 103 // TooHighPSI Port Injection // THPSI Billet Lid // FF // Katech Drop-In // PLM Heat Exchanger // ZLE Cradle bushings // BMR Chassis-Suspension Stuff // aFe Bars // Diode Dynamics LEDs // ACS Composites Guards // CF Dash // Aeroforce // tint // other stuffs

06-07-2021, 08:14 AM	#9
KingLT1 Drives: 2016 1SS NFG A8 Join Date: Aug 2017 Location: 46804 Posts: 6,793	Nice work...Somebody needs to start selling those! __________________ 2016 NFG 1SS A8 Options-2SS Leather/NPP Perf. mods-Whipple 2.9/Fuel System/Flex Fuel/103mm TB/Rotofab Big Gulp/Cat Deletes/Corsa NPP Per. times- 10.5 @ 137 w/ 1.8 60ft Full weight on 20's 1200DA

06-07-2021, 09:15 AM	#10
FoundNemo Drives: 2019 ZL1 Join Date: Oct 2019 Location: GA Posts: 573	I would 100% be in for a re-piped cat section with Gesi cats!

06-07-2021, 03:25 PM	#11
Revalot Drives: ZL1/1LE parts added Join Date: May 2018 Location: Somewhere around Texas pines tress and smooth asphalt Posts: 609	Great Welds !

06-07-2021, 06:31 PM	#13
cmitchell17 Drives: 17 2SS, 8L90, Cam, Heads, E85 Join Date: Dec 2016 Location: US Posts: 1,200	So it looks like you completely cut the ends of the GESI cats and just welded the circular portion of the GESI cats back to the stock cats end? Is that correct? I really want to attempt this, I just feel like I would fail miserably. My plan would be to cut the stock exhaust to the downpipe portion and bolt it to the car, then try to fabricate a holder/jig while under the car. Problem is I know this would be a dumb idea trying to do it, I've already made plenty of scars on my arm from burned slag hitting them while on my back under a car/truck trying to weld exhaust. I would need a lift for this. I would gladly pay you and I'm sure there are a lot of other here too that would to make a setup like this. One really big question I have is how is the sound quality? particularly how is the radiated non-exhaust noise? Is it similar to stock? I am talking about the ticking and other noise that is radiated from the exhaust itself and not actually the exhaust sound that comes from the end of the pipe.

06-07-2021, 06:34 PM	#14
cmitchell17 Drives: 17 2SS, 8L90, Cam, Heads, E85 Join Date: Dec 2016 Location: US Posts: 1,200	Now that I think about it, if the GESI cats and the stock cats are similar in circular diameter, and if I didn't care about having the supposed stock downpipe bottleneck/restriction then it seems like it shouldn't be too difficult to cut out just the circular section, which it looks like you did, and just cut the circular section out of the GESI cats and weld them back in.

User Name		Remember Me?
Password