Anyone ever install Cats on their OBX headers?

[Johnny5]

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]

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

[MuRCieLaGo]

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]

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]

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]

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]

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]

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

[Gunny]

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 (http://www.zr1.net/forum/showthread.php?t=10935&highlight=cats) plus some good pics of the install.

[Johnny5]

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?

[KILLSHOTS]

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?
The "fake cats" on the OBX headers are separate pieces. Just leave them off.

[Johnny5]

The "fake cats" on the OBX headers are separate pieces. Just leave them off.

Really? I never saw a pair in person. So I can just buy the OBX, buy (2) 3 inch inlet/outlet universal cats, have a shop fabricate them so one side comes to 2.5 inch to my corsa and I should be good?

I was under the impression that the OBX Bolts right up to the stock system so the cats that i buy would have to be the same size as the "fake ones" I won't be using correct? (to not throw off any alignment issues of my current cat back.) Does anyone know that length?

Sorry for all the questions but I wanted to do research if i would be saving $$$$ buying OBX and putting my own cats on as opposed to buying SW with cats for $1220.

[Karl]

The end of the obx are hollow 3" in and out with a slight rise. A bullet type catalytic converter would most likely fit best.

These are mine without the end pieces.

http://s5.postimg.org/3kldhgker/20131207_103942.jpg (http://postimg.org/image/3kldhgker/)

[KILLSHOTS]

Really? I never saw a pair in person. So I can just buy the OBX, buy (2) 3 inch inlet/outlet universal cats, have a shop fabricate them so one side comes to 2.5 inch to my corsa and I should be good?

I was under the impression that the OBX Bolts right up to the stock system so the cats that i buy would have to be the same size as the "fake ones" I won't be using correct? (to not throw off any alignment issues of my current cat back.) Does anyone know that length?

Sorry for all the questions but I wanted to do research if i would be saving $$$$ buying OBX and putting my own cats on as opposed to buying SW with cats for $1220.
Yes, mine bolted right up to the Corsa system using the supplied bullets. There will be no difference in system sound with different brands of headers. I really wanted SW headers and was willing to pay more for them, but not nearly twice as much. I would suggest having them coated prior to install. Good luck.

[Johnny5]

AAAH someone told me OBX came with fake cats so i assumed they were welded on and the ebay pic makes it look like its all 1 piece. Thanks guys!!

[Paul Workman]

AAAH someone told me OBX came with fake cats so i assumed they were welded on and the ebay pic makes it look like its all 1 piece. Thanks guys!!

Suggest you use some of the saved $$$ to have it dyno tuned, asap.

You can have Marc Haibeck or Corry Henderson provide a pre-programmed chip that will get you in the ball park, and you can drive (read: HAMMER!) it immediately. Also, Marc programmed my fans to both come on at ~205º and turn off at ~ 200º, as well as adding anti-backfire fueling.

However, dynamic tuning, i.e., on a dynojet or whatever, is the best way to get the last few ponies out of your mods.

:cheers:

[KILLSHOTS]

Suggest you use some of the saved $$$ to have it dyno tuned, asap.

You can have Marc Haibeck or Corry Henderson provide a pre-programmed chip that will get you in the ball park, and you can drive (read: HAMMER!) it immediately. Also, Marc programmed my fans to both come on at ~205º and turn off at ~ 200º, as well as adding anti-backfire fueling.

However, dynamic tuning, i.e., on a dynojet or whatever, is the best way to get the last few ponies out of your mods.

:cheers:
No question about this. Marc will add fuel so that you can take full advantage of the header swap, and the anti-backfire thing is an absolute MUST! Marc missed that in my initial tune (he fixed it for me immediately and at no charge, of course) and my Z backfired VIOLENTLY on every shift.

[Johnny5]

Okay, so I bought the Oil Dipstick from Paul, Header Gaskets from Jerry, Stage 8 bolts from Summit Racing, going to buy high temp copper Permatex from Autozone tomorrow....Now it is New OBX for $550 or used Watson headers for $700.

I have to find out which cats to buy and get them fabricated to slip one end on my 2.5 inch Corsa exhaust.

The last thing is whether or not i need an O2 extension and where to buy them. I bought new O2 sensors and see the 3 prong clip.

Do i defnitely need an extension and where would I find one for our cars?

[Ccmano]

Old thread here but it looks like the original question was never answered. What cats are other using with OBX headers.

I just installed an OBX system, headers and exhaust. I can’t stand the stink at idle, thinking about adding cats. I’m curious to see what other have installed.

Thanks
H
:cheers:

[Johnny5]

No cats will bolt right in. I bought magnaflows and has them welded to ibx bracket to bolt to catback exhaust

Cheaper than buying stainless works cats for $500

[-=Jeff=-]

I have magnaflow cats with Watson headers. I have a set of C6Z06 cats I want to try


Sent from my Nexus 7 using ZR-1 Net Registry mobile app (http://r.tapatalk.com/byo?rid=90383)

[PhillipsLT5]

Random Tech cats, stainless works headers, corsa cat back