[nated]

I want to convert my 77 TA (W72) to dual exhaust but I'm wondering what kind of restrictions there are for California? My current exhaust setup is stock.. single cat, one muffler with dual out.

My guess is that you cannot mess with any thing before the cat. Which means NO true duals?
If that is the case, I was thinking maybe a new single high flow cat to dual mufflers? Which I think is the same as the 78 TA (W72)?

If anyone has a good link to the CA smog laws (regarding equipment etc) I would appreciate it.

Thanks
Nate

[nated]

I want to convert my 77 TA (W72) to dual exhaust but I'm wondering what kind of restrictions there are for California? My current exhaust setup is stock.. single cat, one muffler with dual out.

My guess is that you cannot mess with any thing before the cat. Which means NO true duals?
If that is the case, I was thinking maybe a new single high flow cat to dual mufflers? Which I think is the same as the 78 TA (W72)?

If anyone has a good link to the CA smog laws (regarding equipment etc) I would appreciate it.

Thanks
Nate

[ontheblocks]

Wait 4(?) more years until you are exempt???

If it has ti*s or tires, it's gonna cost ya!

[ontheblocks]

C.A.R.B.

If it has ti*s or tires, it's gonna cost ya!

[ontheblocks]

30 year plan:

CARB link #2

I started looking for you, and there is a lot to sift through. Seems that a high flow cat with 3" pipe going to a muffler in the stock location will satisfy a visual inspection, the sniffer will be you pass/fail point. Hope this helps

If it has ti*s or tires, it's gonna cost ya!

[axle]

if you can find a "good ol boy" muffler shop who doesn't give a crap....jack your car up,saw off the exhaust past the manifold,remove the pipes,cat,muffler,etc,...drive over to the muffler shop (a little loud) and tell the guy you need dual exhaust...he might not even know (might not even care) it came with a cat and will probably do the job.
save the cat..if you sell the car pay a muffler shop to re install it.
thats what i'd do! alex
p.s.
i'm sure your car will run a hell of a lot better with the new system!
p.s.s
never seen a cop in california pull someone over to check an exhaust system!

[nated]

Thanks for the link, this is what I found as the exception to one of the rules(27156)

h) This section shall not apply to an alteration, modification, or modifying device, apparatus, or mechanism found by resolution of the State Air Resources Board to do either of the following:

(1) Not to reduce the effectiveness of any required motor vehicle pollution control device.

(2) To result in emissions from any such modified or altered vehicle which are at levels which comply with existing state or federal standards for that model year of the vehicle being modified or converted.

From that it sounds like you can modify anything as long as you are not making it less effective. This also sounds like you can make changes to mufflers because they have nothing to do with pollution. However, I have a feeling the part I found is only a small section of the CARM laws.

[ontheblocks]

Nate,

I haven't looked, but I believe there is a visual inspection also, so if a true dual exhaust wasn't offered, you technically can't put one on. That is why the aftermarket companies offer larger diameter systems to bolt on in the stock locations.

If you find a shop that only worries about the tail pipe emissions, you should be able to get by with whatever you hook up. From my limited experience, most well tuned older cars will pass the part throttle test, it is the idle HC and NOX levels that will fail you, unless you have a catalytic converter that is functional, or you have the idle tuned on the carb to specifically lower the score.

Personally, I would go with a 3inch Y pipe into an aftermarket high flow cat, and 3inch pipe to a new muffler. You'll pass emissions, and the system won't cost a lot. 4-5 years later, if you really want it, you can put a dual system on when the car is exempt.

If it has ti*s or tires, it's gonna cost ya!

[JC455]

I agree w/ your thinking Larry. If you really want to do something, I've put a few ideas up before, but here are some random thoughts...
1) Hedman shorty headers, 2-1/2" Y-pipe into Flowmaster 2 into 1 Y-pipe connector. 3" high flow cat into 3" exhaust out the rear. A little illegal due to headers, but they really don't effect emissions.
2) Same system w/ cast iron RA III manifolds. Would easily pass for factory smog stuff.
3) Install a set of flanges on both sides of the cat. Install a "test" pipe for off road use only, of course , Then you can reinstall the cat when it's testing time.
The 3" system w/ no cat will be rather rumbly. I've got a factory 2" pipe into a 3" cat w/ 3" 2 chamber flowmaster on a 76- very throaty even w/ the cat installed.

John

[nated]

Thanks for the ideas guys

I did some more reading and from what I found you can put a cat-back system on any car in california. I mean, if they sell these cat-back systems for a damn honda, why not a pontiac!
Also, anything before the cat must be "50 state legal" ie a CARB EO # then its good to go.

Anyone know of 50 state legal headers that I can use? I know they are out there.

[nated]

oops.. didnt realize the hedmans were 50 state!
thanks