Tom M'Guinn

Does anyone have a Smog II test result from a 951 they could post. The more the better. I am interested in comparing acceptable emissions levels (ppm) for 86, 87, 88 and 89 cars.

Also, if anyone has been sent to a smog-only station because your car falls within the High-Emitter-Profile, please speak up and be sure to include the year of your car. I have heard several 89 owners getting tagged by this, but have not heard of any 86's yet.

From what I can gather, the acceptable levels were slightly higher for 86 cars, compared to 87 - 89, but I would like to confirm with real-world experiences. Thanks.

josephsc

Funny you ask -- I just did it on Saturday for a completely stock '88 951S with 97K miles I got two weeks ago, last registered in Utah. This was a test-only station (by choice). I got....

15mph (1600 rpm) (Max/Ave/Meas)
HC: 116 / 31 / 73
CO: 0.74 / 0.10 / 0.23
NO: 791 / 237 / 580

25mph (2532 rpm) (Max/Ave/Meas)
HC: 91 / 20 / 47
CO: 0.62 / 0.09 / 0.27
NO: 730 / 199 / 592

Let me know if you need more info.

DanD

I've been a high Emitter Profile for both of my cars for the last 3 years. Never failed a test. It's just the year and the type. Heck, smog-only stations don't try to sell you stuff..

Here is mine from last Dec.
86 951 Stock 72k miles

15mph (2426 rpm) (Max/Ave/Meas)
HC: 135 /41 / 77
CO: 0.83 / 0.13 / 0.61
NO: 1136 / 399 / 790

25mph (2432 rpm) (Max/Ave/Meas)
HC: 110 / 29 / 49
CO: 0.63 / 0.11 / 0.16
NO: 966 / 332 / 200

And the other from last week
86 951 Stock 103k miles - but a weak engine

15mph (2426 rpm) (Max/Ave/Meas)
HC: 133 /41 / 84
CO: 0.82 / 0.13 / 0.52
NO: 1125 / 399 / 1109 < - cat is heading south ?

25mph (2432 rpm) (Max/Ave/Meas)
HC: 108 / 29 / 65
CO: 0.62 / 0.11 / 0.18
NO: 955 / 332 / 499

Hmmm, the requirements are creeping down in the last 6 months....

brad-cam

Here is mine from December 2003
87 951 Stock 73k miles

15mph (1588 rpm) (Max/Ave/Meas)
HC: 116 /31 / 110
CO: 0.74 / 0.10 / 0.37
NO: 791 / 237 / 769

25mph (2397 rpm) (Max/Ave/Meas)
HC: 91 / 20 / 31
CO: 0.62 / 0.09 / 0.07
NO: 730 / 199 / 509

As you can see, I just passed ! This was with stock chips and a brand new O2 sensor. The cooling system was screwed up and it was running very hot at the time too.

cas951

This was done in Feb 2004. My car is a 88 turbo S with new Hi-Flow cat from Lindsey and new Oxegen Sensor. I also used 94 Octane gas and drove a good 30 miles before the tes.

15 Mph: 1553 RPM
HC: Max 116 Measured 20
CO: Max .74 Measured .01
NO: Max 791 Measured 13

25 Mph: 2472 RPM

HC: Max 91 Measured 13
CO: Max .62 Measured .03
NO: Max 730 Measured 728

Tom M'Guinn

Thanks Dan, do you happen to have the gross vehicle weight for each of those vehicles handy? Is the first one heavier for some reason -- trying to figure out why the max numbers are slightly higher for the first car.

If anyone else has results to share, it would be helpful, especially for 86 cars.

DanD

Interesting thought. I wouldn't think the weight would affect it
These are the numbers on the smog test sheet.

The first one was 3125# (stock weight whatever that is)

Most recient was 3250# (weights 2900#)

My second car is actually lighter. Fiberglass panels, seats, and so on. Weighted in at 2900 empty. I have to think they weigh with the tester in the car.

Tom M'Guinn

Thanks. Perfect! That exactly explains the difference in max limits. The formula used to calculate the limits is odd -- each limit is set to equal the sum of a constant, plus the result of another constant divided by the vehicle's test weight. For example, the NO limit at 25mph equals 894444.5/vehicle weight, plus 680. If you run the math, that works out to a limit of 966 for a 3,125 pound car, and a limit of 955 for a 3,250 pound car. So... the higher the gross vehicle weight, the lower your limits!!!! This also confirms that the 86 cars have lower limits than the 87-89 cars in Cal -- based on the chart California uses. If your car were an 87, for example, the NO limit would for your 3,125 pound car would be 738 at 25mph. The 86 cars are subject to limits applicable to 84 through 86 cars. The 87-89 cars get lumped in with cars build from 1987 through 1992 -- so I suspect the 87-89 cars will test much closer to their limits.

DanD

I'm not following. So do I empty the car of weight or fill it with lead before a test?

Tom M'Guinn

Sorry to geek-out on you -- I was just so happy to finally understand the system. I think they use the official gross vehicle weight of the car, rather than the actual weight you have when you get tested. So I don't think it matters what the actual weight is at the test. However, all other things equal, the car with the lower (official) gross vehicle weight will have higher test limits (i.e., the lower the GVW, the easier the test).

Tom M'Guinn

I PASSED! After several weekends of work, the car passed with low-flying muted colors.

15MPH: (CO2= 14.2; 02= .4)
HC Limit 135; measured 125
CO Limit .83; measured .40
NOx Limit 1136; measured 1125 (if it were an 87, it would have failed here)

25MPH: (CO2= 14.6; O2=.1)
HC Limit 110; measured 37
CO Limit .63; measured .10
NOx Limit 996; measured 409

Before the test, I replaced the plugs, some rubber hoses, O2 sensor, stock chips, injectors, etc. The only non-stock part was the Huntley turbo -- but I ran the stock J boot (thanks to Danno's tip), airbox, etc. It was over 90 degrees today, which may have added to the NOx. The much lower NOx at 25mph makes me wonder if there is a small vacuum leak, which has lesser impact at higher rpms. I am not too excited about the high NOx at 15mph -- my results would have failed on an 87 car. Guess I should be happy just to have passed...

H2Opumpr

I have been going through this stuff for the past five years. It is the worst part about this car, in fact I have been a gross polluter 3 times and have always had to go to a test only facility. THe last two times I have barely squeeked by,... the car runs fantastic by the way. Almost all sensors and engine management components have been replaced.
The biggest difference I've ever seen in numbers has been by having all three cells in the cat functioning properly. Usually one part burns out and the corresponding chemistry fails. High running temps are to blame. Some people say get your car hot before you test... well in a 951 dont, it makes the NOX fail. I've never failed on HC production always N0X, just like evryone else who posted. Try not to get it so hot, I know it's not popular but it works.
Run a cat bypass and save your valuable cat for when the time is right... during testing!

Tom M'Guinn

H2Opumper, did you end up buying a new cat and, if so, did it bring your NOx down? Everything in my car is pretty much new except for the cat, so I'm not sure what else I'd do to get the NOx down. I'll check for vacuum leaks again, and maybe get get it tested in cooler whether next time. Other than that, the only other thing I can think of is a new cat.

H2Opumpr

Tom

As it has been explained to me ...that generally on our cars the NOx goes bad first. If you do a search online about the chem involved, you tend to find info supporting this idea. When I replaced the cat from a 951 with 80,000 miles I blew through the test easily. I just redid my motor last year and then had a hell of a time passing again. But to answer your question is that you can have a poorly tuned motor and put a new cat on and clean it up really well, its amazing what a new cat will do especially the new technology cats. Carsound makes a pretty good cat, made by magnaflow, that does a pretty good job with performance also. Good luck next time, I still have another year before the dreaded smog **** test!

pflyers

If your in Los Angeles, there is a smog place in Burbank that is VERY 951 friendly.
The owner is a young guy who used to own one and loves these cars. If you ask him to run it off the computer he'll do it for you so Sacremento can't see the results. this way you can see where your at and see if he can get it to pass.

very reasonable, friendly porsche mechanic 1/2 mile from there too.
petesautotech.com

Highly recommended

It's a test only center.

going north on I5 exit on alameda in burbank. Go east, go north on Glenoaks 2 blocks and it's on the left hand side.