Failed Smog, need advice

[va122]

Hey,

So I tried smogging the GT3 and it failed CO2. They guy at the shop told me to put some low octane gas, and bring the car in hot and don't turn it off before the test.

My other option is to put the stock exhaust and cats back on but the labor on the R and R is a LOT since it's a header back system.

Any advice would be appreciated.

Vic

[LUCKY DAVE]

This is a general theme, not applicable to a specific car.
(advice version #1) Install the stock exhaust W/cats and the stock chip. If adjustalbe, set idle mixture staggeringly lean. Bring the car into the smog shop hot (full throttle freeway run into the driveway if possible) and don't shut it off before it's run on the rollers.
(advice version #2 ) Take the car, and the stock exhaust W/cats/stock chip to Black Forest or Dieters, and let them deal with it.
In any case, make sure there isn't any race gas left in the tank, even diluted.
Trying to get a car to pass with a performance chip and without working cats is an excercise in futility.

[harnishclan]

Do it right. Go to Dieter's/Black Forest/whoever you trust and knows Porsches.

If you make the car too lean, HC goes up and you fail anyway. That on top of risking burnt pistons and other damage due to detonation and pre-ignition, a far more expensive proposition than a header swap. About the only thing you can do is get rid of any race fuel in the system, clean fuel/air filters, fresh spark plugs, get it hot and do not let it cool down until after the test is complete.

Last option is to PNO the car and make it a full time track toy.

[Autobahn]

How far off are the numbers?

[LUCKY DAVE]

If you make the car too lean, HC goes up and you fail anyway. That on top of risking burnt pistons and other damage due to detonation and pre-ignition, a far more expensive proposition than a header swap.

Lean mixture will decrease HC while increasing NOx.
I wouldn't worry about burning up anything just during an emissions test by running a very lean mixture. It's not like you're going to leave it that way.
The stock mixture is pretty lean, and the engine survived that before it was modified.

[harnishclan]

NOx will go up with heat as a result of increased temperature within the cylinder. HC will go up with very lean mixture as a result of misfire and therefore incomplete combustion. Either way it is a fail point and I revert to my first opinion-let a professional fix it correctly. Cheaper and less hassle in the long run.

[MR LIPP]

I think you need to go old-school.

[Dan Chambers]

Do it right. Go to Dieter's/Black Forest/whoever you trust and knows Porsches.

+1. If you can afford the GT3, and afford the risks of modifying it for track and tracking it, you'll need to belly-up to the consequences of the cost to get it smogged right, IMHO.

From my experience, both Dieter's and Black Forest do a really good job with this kind of thing, and usually stay spot-on to their initial quote, unless your car has some serious problems (problems that should be fixed if your tracking it, anyway ).

So I think you should just bight the bullet, take it to a good shop; have all the "correct parts" put on and all the electronics "adjusted" for smogging, and be done with it.

With my SC, I re-install the hardware myself, take it to B.F., who then "de-tune" it for proper smogging; take it down and get the cert. for me; bring it back and "re-tune" it for competition; and get it back to me ... all in one day. Yeah, a few "Ben Franklin's" are donated to the cause ... but it's a worthy cause, IMO.

Just do it right, and plan the expenses into your fun-budget.

One more thing: one year, I had an oops with the smogging of a vehicle that temporarily "bumped" it into the "gross-polluter" catagory. I had to smog the car every year for 3 years before I could go back to the two-year smog cycle. So, be wise and beware. You don't want to go through this drill every year.

Just my 2-cents. Good Luck!!

DC

[va122]

Thanks Guys,

I'm going to try again with 87 octane first before I go the header/cat route. (glad i saved those)

I'll re-post to let you know how it turned out

[Jackie C]

There are "rural areas" of San Diego County that don't require a smog if you can get an address or PO Box there. No smog required in AZ either...

[Dan Chambers]

There are "rural areas" of San Diego County that don't require a smog if you can get an address or PO Box there. No smog required in AZ either...

Naughty, naughty. Clean air is everyone's friend. (Now, I'm going to go hug another tree.)

[richard]

My nephew is a Toyota factory mechanic. He uses about 6 bottles of drygas. Make sure it contains the iso something or other-the most expensive dry gas. He has put a sniffer in the tailpipe and watched the emissions go down. Don't recall which part of the emissions however. I have no idea if it will work for the GT.

FYI-My '84 Carrera passed last emissions by one part in a million without a cat. Can't get any closer than that. Didn't try the drygas trick.

[MTrotter]

use math, E-85 and regular 87 and get the mixture to about 40 percent alcohol. Keep volume really low as you need to burn this all out in one day to prevent your rubber hoses and o-rings to exposure to the alcohol. Always, always always get the car really really hot! never test a car that has lest than 20-30 hard (as hard as you can put on it on the street anyways). Dont turn it off and try to arrange to have it put on the rollers and sniffer right away.
I have done this with quite a few cars... never a GT3, but quite a few car and have never had any problems. This in including a few German cars, Japanese cars and just for an example... my 2001 Subaru RS 2.5 measured: HC.. 16 with a max of 100 at idle, 5 with a max of 130 at 2500 rpm and on the CO .. 0 at idle . max 1.0 and 0.0 at 2500 max 1.0
I can go through the rest of my cars and prove my point.. but this one speaks for its self.
Check with someone about the E-85 and get it really hot with the premium, add the E-85 close to the shop. Do your math carefully. Dont drive too hard with the mixture. Your mechanic can tell you if the E85 mixture will hurt the motor.

[MR LIPP]

There are "rural areas" of San Diego County that don't require a smog if you can get an address or PO Box there. No smog required in AZ either...

and if you get busted, just tell them

[va122]

Thanks Guys again, I failed using 87 octane and hot cats.

I fail only at idle, 2500rpm is fine. So I talked to my friend who is the USA Cargraphic distributer and he's going to call Germany in the morning for me. No other car that has the same exhaust as I do has failed. Who knows I may get some new cats out of it.

If all else fails Martin and I will R&R the Cargraphic and I'll smog with the stock cats.

Now Jackie's idea has real merit. Where can I find out more about these "rural" areas?

V