Anyone ever install Cats on their OBX headers? - ZR-1 Net Registry Forums

Johnny5 · 04-11-2016

I want to buy these but don't want the gas smell or extra loudness if there us no cats, although i never heard OBX with corsa. Did anyone ever rig up cats to their OBX headers?

thirstyzr1 · 04-11-2016

A GF of mine has a 92 ZR-1. Ceramic coated OBX with high flow cats. Unsure of the rest of the system.

MuRCieLaGo · 04-11-2016

I got a Borla exhaust with a Magnaflow resonator (replacement to the OEM) and I just installed OBX headers (removed cats).

Headers didn't change the sound pretty much. I have a hard time hearing a difference.

The car stinks like hell though...

Johnny5 · 04-12-2016

Quote:

Originally Posted by thirstyzr1

A GF of mine has a 92 ZR-1. Ceramic coated OBX with high flow cats. Unsure of the rest of the system.

I'd be curious to see her set up if they cut the glass packs out and welded in cats or just slipped it on. I would like to do something like that to save $1000 over SW headers. Is she on this forum? If not would you be able to PM me a way to contact her? I would love to do the exact same set up.

RussMcB · 04-12-2016

The OBX headers I bought did not have the fake cat bulge.

When I took it to a custom exhaust place (with a good reputation), he convinced me to run without the hi-flow slip-on aftermarket cats I had brought along for installation.

His reasons were, they don't do much towards either improving emissions or reducing the gas smell (or drone), and since I don't need to worry about emissions in GA with a 25 YO car, I opted to not use them.

However, I'm sure he could have installed them without any issues. They would have slipped on and clamped just as well as the pipes he used, right?

My headers did not have a long straight section at the end (maybe 1" or so?), but it didn't seem to be a problem for him to connect the pipes and clamp them. I haven't seen any evidence of leaks (and I've looked for them).

Johnny5 · 04-12-2016

Quote:

Originally Posted by RussMcB

The OBX headers I bought did not have the fake cat bulge.

When I took it to a custom exhaust place (with a good reputation), he convinced me to run without the hi-flow slip-on aftermarket cats I had brought along for installation.

His reasons were, they don't do much towards either improving emissions or reducing the gas smell (or drone), and since I don't need to worry about emissions in GA with a 25 YO car, I opted to not use them.

However, I'm sure he could have installed them without any issues. They would have slipped on and clamped just as well as the pipes he used, right?

My headers did not have a long straight section at the end (maybe 1" or so?), but it didn't seem to be a problem for him to connect the pipes and clamp them. I haven't seen any evidence of leaks (and I've looked for them).

what cats should i buy to fit the OBX headers into the 2.5 inch Corsa? They have to get rid of gas smell; (at least somewhat) that's what catalytic converters do, they burn the excess gas off

RussMcB · 04-12-2016

Quote:

Originally Posted by Johnny5

what cats should i buy to fit the OBX headers into the 2.5 inch Corsa?

(If that question is directed to me...) I don't know.

My guess is it would be as simple as finding some with the correct inlet/outlet OD/ID to match what you're connecting them to.

Will you be doing the installation yourself, or hiring someone?

Johnny5 · 04-12-2016

With Wazoo guys when they can fit me in. I am just trying to get answers on the OBX with cats first.

Gunny · 04-12-2016

If the OBX collectors are 3" I think you will be more pleased with 3" bullet cats. The shorter the cats, the better and you still may need to shorten the cat on the muffler side when you reduce to the 2-1/2" of the Corsas.

The best setup that I used was to slip joint the cats to the headers and then v-clamp the other end of the cats to the reducer. Very quick & easy to drop the entire exhaust system when needed.

A setup that I was interested in (but never tried) is on Phil's Z ... he used braided stainless connectors to the exhaust pipes. Here's the LINK plus some good pics of the install.

Johnny5 · 04-12-2016

The OBX headers are designed to bolt up to the factory exhaust or Corsa like I Have. SO what my #1 QUESTION is how are the cats installed on OBX Headers than connected to the cat back??????

Do you have to cut out the fake cats? than weld in aftermarket cats, than weld on the 3 bolt flange for driver side and slip on for passenger side?

04-11-2016	#2
thirstyzr1 Join Date: Sep 2012 Location: Ontario Posts: 111	Re: Anyone ever install Cats on their OBX headers? A GF of mine has a 92 ZR-1. Ceramic coated OBX with high flow cats. Unsure of the rest of the system.

04-11-2016	#3
MuRCieLaGo Join Date: Aug 2014 Location: Trois-Rivieres (QC) Posts: 473	Re: Anyone ever install Cats on their OBX headers? I got a Borla exhaust with a Magnaflow resonator (replacement to the OEM) and I just installed OBX headers (removed cats). Headers didn't change the sound pretty much. I have a hard time hearing a difference. The car stinks like hell though...

04-12-2016	#5
RussMcB Join Date: Jan 2015 Location: Marietta, GA USA Posts: 1,160	Re: Anyone ever install Cats on their OBX headers? The OBX headers I bought did not have the fake cat bulge. When I took it to a custom exhaust place (with a good reputation), he convinced me to run without the hi-flow slip-on aftermarket cats I had brought along for installation. His reasons were, they don't do much towards either improving emissions or reducing the gas smell (or drone), and since I don't need to worry about emissions in GA with a 25 YO car, I opted to not use them. However, I'm sure he could have installed them without any issues. They would have slipped on and clamped just as well as the pipes he used, right? My headers did not have a long straight section at the end (maybe 1" or so?), but it didn't seem to be a problem for him to connect the pipes and clamp them. I haven't seen any evidence of leaks (and I've looked for them).

04-12-2016	#8
Johnny5 Join Date: Nov 2014 Location: New Jersey Posts: 363	Re: Anyone ever install Cats on their OBX headers? With Wazoo guys when they can fit me in. I am just trying to get answers on the OBX with cats first.

04-12-2016	#9
Gunny Join Date: May 2005 Location: Georgia Mountains Posts: 926	Re: Anyone ever install Cats on their OBX headers? If the OBX collectors are 3" I think you will be more pleased with 3" bullet cats. The shorter the cats, the better and you still may need to shorten the cat on the muffler side when you reduce to the 2-1/2" of the Corsas. The best setup that I used was to slip joint the cats to the headers and then v-clamp the other end of the cats to the reducer. Very quick & easy to drop the entire exhaust system when needed. A setup that I was interested in (but never tried) is on Phil's Z ... he used braided stainless connectors to the exhaust pipes. Here's the LINK plus some good pics of the install.

04-11-2016	#1
Johnny5 Join Date: Nov 2014 Location: New Jersey Posts: 363	Anyone ever install Cats on their OBX headers? I want to buy these but don't want the gas smell or extra loudness if there us no cats, although i never heard OBX with corsa. Did anyone ever rig up cats to their OBX headers?