California Smog Conversion

After much research I have started converting my LS6 powered 944 to pass CA smog, I gathered parts from a 2002 Camaro and plan to get my BAR inspection based on that year and model.

So far things are going very well, I have fitted most of the upper smog components (Air tubes, Smog pump, Evap Valve), I still have to do all the wiring.

I have also done some upgrades while preparing the car for smog, I added a fresh set of 243 heads, Hydro-boost master cylinder, tubular front control arms and a Griffin radiator. The car runs a pretty aggressive cam for CA smog, I have a tuner who is confident he can get the car to pass a sniffer test.

2002 Camaro Parts list;

- Camaro Cats, need to modify to fit under 944 (BAR specifies Cats must be withing 3" of original spot)
- Air Pump, will mount in battery tray
- Evap Valve plumbed into stock fuel tank vent
- Stock LS1 fuel pressure regulator
- Need to find CARB certified air filter with sticker
- Eldabrock shorty CARB certified headers with CARB E.O number
- Front + Rear O2 sensors
- Steering link modification to clear stock Camaro headers

I am still figuring this out as I go along but I think I have all I need to pass the inspection, the tricky part is going to be modifying the Cats.

[You must be registered and logged in to see this image.]

What headers are those? If those headers have EO, you should be able to source EO cats?? Trick is still the steering shaft.

I am pretty sure to get passed at CARB, you will need to fit the original exhaust manifolds. I only say that because that is the only way I have seen the steering shaft fit with out using custom headers. Even the stock exhaust manifolds will need a little tweaking at the exhuast flange. Also the cats will need to be cut to fit. I borrowed member ACORAD's modified manifolds and steering shaft. I was surprised that on the manifold only the drivers side needed modding and only at the exhaust flange and the head side just needs to be shaved (I had read that it would need a 10 degree cant).

I made a sketch of the steering shaft. I'll have to dig it up. Dont know if I can scan it. There is a picture in my gallery of the upright you will need for the modified shaft. The picture is actually of Acorad's car before he bought it.

Bluemach1 wrote:What headers are those? If those headers have EO, you should be able to source EO cats?? Trick is still the steering shaft.

I am pretty sure to get passed at CARB, you will need to fit the original exhaust manifolds. I only say that because that is the only way I have seen the steering shaft fit with out using custom headers. Even the stock exhaust manifolds will need a little tweaking at the exhuast flange. Also the cats will need to be cut to fit. I borrowed member ACORAD's modified manifolds and steering shaft. I was surprised that on the manifold only the drivers side needed modding and only at the exhaust flange nothing at the head side (I had read that it would need a 10 degree cant).

I made a sketch of the steering shaft. I'll have to dig it up. Dont know if I can scan it. There is a picture in my gallery of the upright you will need for the modified shaft. The picture is actually of Acorad's car before he bought it.

Thanks, I would appreciate whatever information you have.

Yes, I have seen ACORAD's picture, I have a little less clearance due to the Eldabrock headers but enough to get the steering shaft between the frame and headers.

The headers are Edelbrock Shorty Headers, model # 65732 for 2000-2002 Camaro and Trans Am vehicles (Carb # D-215-58). These headers have stock flanges and are designed to fit a stock Camaro's Cats, they are CA legal and are the only exhaust upgrade you can do in CA.

Where are you at in CA?

Bluemach1 wrote:Where are you at in CA?

I'm in North San Diego.

You're much better off using a set of aftermarket California approved cats. I don't think there's anyway you're going to fit those OEM Camaro cats underneath a 944. Certainly not without scraping them off everytime you drive over a pebble...

docwyte wrote:You're much better off using a set of aftermarket California approved cats. I don't think there's anyway you're going to fit those OEM Camaro cats underneath a 944. Certainly not without scraping them off everytime you drive over a pebble...

It has been done. It's just not a great long term solution. Out here you just need to get past the California Air Resouces Board (CARB) referree. Once you have done that, and if you know people that can smog your car every two years, you can pull off the stock equipment and put on what every you like.

I will be very interested in seeing if the Edlebrck 65732 headers can work with a modified steering shaft. I am pretty sure this has been tried but the tubes are located in such a manor that you cant get around them on the frame side or the block side.

Weird seeing pics of my car that I haven't seen before!

Bluemach1 wrote:

docwyte wrote:You're much better off using a set of aftermarket California approved cats. I don't think there's anyway you're going to fit those OEM Camaro cats underneath a 944. Certainly not without scraping them off everytime you drive over a pebble...

It has been done. It's just not a great long term solution. Out here you just need to get past the California Air Resouces Board (CARB) referree. Once you have done that, and if you know people that can smog your car every two years, you can pull off the stock equipment and put on what every you like.

I will be very interested in seeing if the Edlebrck 65732 headers can work with a modified steering shaft. I am pretty sure this has been tried but the tubes are located in such a manor that you cant get around them on the frame side or the block side.

I see, there will be more clearance with stock headers. I can build the modified steering shaft to work with the current headers, there is not allot of space between the frame and headers so it will be tight.

Regarding the steering shaft, is the bracket that holds the heim joint welded to the fame or is it bolted?

The heim bracket that I have is actually part of the drivers side upright. If I could easily dig out of of my pile of stuff, I would get a picture for you. That is if you are going to run the stock exhaust manifolds. If you are going to try to make the headers work, which I would really like to see, you might have to attach to the frame rail somehow...

Bluemach1 wrote:The heim bracket that I have is actually part of the drivers side upright. If I could easily dig out of of my pile of stuff, I would get a picture for you. That is if you are going to run the stock exhaust manifolds. If you are going to try to make the headers work, which I would really like to see, you might have to attach to the frame rail somehow...

Sure, if you can find it, please post a picture.

I'm still trying to decide if I'm going modify the stock 944 shaft or pick up aftermarket joints and 3/4" shaft. Since the 944 shaft is around 17mm, I would have to remove the joints and weld in a 3/4' shaft to match the mid U joint and heim joint.

Ted, sent you a PM.

Bluemach1 wrote:The heim bracket that I have is actually part of the drivers side upright. If I could easily dig out of of my pile of stuff, I would get a picture for you. That is if you are going to run the stock exhaust manifolds. If you are going to try to make the headers work, which I would really like to see, you might have to attach to the frame rail somehow...

Decided to use stock Camaro Exhaust Manifolds, there is not enough space for the steering shaft and O2 sensor with the Eldabrock headers.

I picked up a set of early Camaro/Firebird Exhaust Manifolds but the RH is different and doesn't fit, GM must have changed the design after 1998. Since the LH stock header fits, I may use the Eldabrock on RH but I'm not sure if the referee will notice different manifolds.

Those guys are picky and know their stuff. I'd count on them noticing that the manifolds are different.

docwyte wrote:Those guys are picky and know their stuff. I'd count on them noticing that the manifolds are different.

Yea, though so!!

I should be able to get a cheap pair from Ebay.

Changed a few more things. After taking a closer look at my Air pump and wiring, I realized I have the wrong unit. The current unit is form an early Trans AM and uses different PCM wiring, plumbing and solenoid than 1999 up Camaro/Trans AM units.

What have you guys done for EVAP plumbing?

I understand that Camaro's use a Carbon Canister with vent solenoid attached to the gas tank, I was thinking building a similar system at the front of the car using Camaro Canister, Vent Solenoid attached to the EVAP purge solenoid.

Easy to do, I have a GM canister unit installed, the solenoid was not a problem. Not sure if it is really required where I live, just decided to do it.

87-944S wrote:Easy to do, I have a GM canister unit installed, the solenoid was not a problem. Not sure if it is really required where I live, just decided to do it.

Ok, Thanks!!

I got lucky in that regard, I have the Porsche stuff and used HP Tuners to force the evap readiness monitor to read "set". The inspectors didn't go digging around for the Camaro Evap stuff...

docwyte wrote:I got lucky in that regard, I have the Porsche stuff and used HP Tuners to force the evap readiness monitor to read "set". The inspectors didn't go digging around for the Camaro Evap stuff...

I see.

I have EFILive and built my own tune, I have full control over all options but still want to get as much smog stuff working as possible.

docwyte wrote:You're much better off using a set of aftermarket California approved cats. I don't think there's anyway you're going to fit those OEM Camaro cats underneath a 944. Certainly not without scraping them off everytime you drive over a pebble...

Just read this. fwiw, my car has the OEM Camaro cats and I've never had a problem with them, except for the insides of one coming loose and rattling around so much I had it replaced (with another OEM Camaro cat).

Really? Wow. I've seen pics of the OEM Camaro cats and they look massive. I can't imagine a pair of them fitting underneath the car and not scrapping. I scrap my 3" test pipes going over speed bumps now.

acorad wrote:

docwyte wrote:You're much better off using a set of aftermarket California approved cats. I don't think there's anyway you're going to fit those OEM Camaro cats underneath a 944. Certainly not without scraping them off everytime you drive over a pebble...

Just read this. fwiw, my car has the OEM Camaro cats and I've never had a problem with them, except for the insides of one coming loose and rattling around so much I had it replaced (with another OEM Camaro cat).

Can you post a picture of the orientation of the stock cats?

About half way down the post, shows that it can be done and they did not hang down any lower than the normal exhaust.
[You must be registered and logged in to see this link.]

Here's mine:

(PS: And I'm glad you had me take these pics. I just looked at them an realized my O2's are after the collector/cat flange. I can hear leaks from the flanges and that would explain why I'm getting P0171 and P0174 codes for Lean Banks, as air's getting in at the flanges and telling the O2's that there's a lean condition. And why my LTFT's are 20%+!)

[You must be registered and logged in to see this image.]