[Supras] emission test standards

[berniek at technicaldevelop.com]

Jon:

    What type of downpipe and exhaust do you have on your car now?  
Rocky's car got better with one cat, maybe because of the age of the two 
originals.

       Bernie

Hacker J wrote:
> Wow, NJ lets you off easy compared to CA, your car would not pass here with those numbers!
>
> Thought it would be interesting to compare my emissions with and without the 1st cat. 
>
>
>
> Bottom line, removing the 1st cat increased my HC and NO significantly.
> My low speed HC is now at 80% and that is a little too close for
> comfort. I've seen my HC emissions climb with every dyno test since 1999. If you are marginal, you will want both cats to pass. No
> doubt lightoff emissions are horribly worse too, but that is not
> tested.
>
>
> If you have some experience in the emissions biz, you'll know that the hardest problem to fix is slightly elevated HC. If you compute my A/F from those emission numbers your get 14.679 (99.8% of stoich) yet I'm running at 80% of the HC limit. Yuck!
>
>
> The % of pass limit is shown in brackets
>
>
>
> Two cats: 
>
> HC 15mph: 51ppm (48.1%)    25mph: 23ppm (28.4%)
>
> CO 15mph: 0.02 (2.9%)    25mph: 0.01 (1.8%)
>
> NO 15mph: 2ppm (0.3%)    25mph: 2ppm (0.3%)
>
>
>
> One cat: 
>
> HC 15mph: 85ppm (80.2%)    25mph: 41ppm (50.6%)
>
> CO 15mph: 0.08 (11.4%)    25mph: 0.02 (3.5%)
>
> NO 15mph: 153ppm (20.1%)    25mph: 50ppm (7.1%)
>
>
>
> Still, not too bad for a 17 year old converter.
>
> Jon
> 90T
>
> ----- Original Message ----
>
> Rocky:
>
>     The NJ standards are as follows for cars of '91 vintage:
>
> NOx:  1077 PPM
> HC:    144   PPM
> CO:    0.81%
>
>     Do you happen to know your standards? 
>
>     Before I tore down my '91 to replace the HG as a preventative 
> measure, my results with the stock dual cat system were 103 for HC, 0.27 
> for CO, and 1063 for NOx.   The EGR might not have been working 
> properly.  But as matters would have it, I found that #1 piston did not 
> come up to the deck (down about .110"), so a bent connecting rod was 
> evident.  So I have about another 20 hours worth of work to complete a 
> freshened JDM installation with a Cometic HG, 550 injectors, Lex AFM, 57 
> trim turbo, and as yet undetermined means of leaning out the top end 
> under boost and possibly retarding the spark about 7 degrees from 7 to 
> 15 PSI boost. 
>
>     The truth is I'm getting a little nervous about passing CO and HC 
> with the 550 and Lex even with the stock dual cats.  The duty cycle of 
> the injectors will be about 20% shorter at idle.  If the injectors are a 
> little unbalanced, HC goes up dramatically with even the slightest 
> misfire, and CO goes up with one richer cylinder. 
>
>        Bernie
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