[Gmecm] Help me get my LT1 a new sticker

ron at gregoryusa.net ron
Thu Sep 15 02:57:48 UTC 2011


> Can you get us a list of the required output?  or what they expect to
> see for a pass with the sniffer?

Here are the limits and all my test results:

TX Standards for 15 mph
[15 mph, 25 mph]
HC - 112, 108
CO - 0.62, 0.60
NOx - 829, 751
Dilution - >6,  >6

Test 1 - no cat-con
[15 mph, 25 mph]
rpm 1400, 1330
HC - 243, 241
CO - 2.18, 2.15
NOx - 1677, 1259
Dilution - 13.6, 13.8
CO2 - 11.4, 11.6
O2 - 3.5, 2.9

Test 2 - new cat-con; removed 4 degrees of timing
[15 mph, 25 mph]
rpm 1332, 1321
HC - 190, 179
CO - 1.83, 1.86
NOx - 1722, 1268
Dilution - 14.4, 14.8
CO2 - 12.6, 12.9
O2 - 2.2, 1.4

Test 3 - removed 6 degrees of timing; set Inj pulse width to 3.0-4.0
ran 25 mph in 2nd gear
[15 mph, 25 mph]
rpm 1338, 1599
HC - 119, 101
CO - 0.12, 0.14
NOx - 1820, 1350
Dilution - 12.1, 12.4
CO2 - 12.0, 12.3
O2 - 3.8, 3.3

Test 4 - removed 8 degrees of timing
[15 mph, 25 mph]
rpm 1437, 1371
HC - 148, 60
CO - 1.31, 0.06
NOx - 1497, 803
Dilution - 13.9, 14.3
CO2 - 12.6, 14.2
O2 - 2.0, 1.1

Test 5 - removed 8 degrees of timing
[15 mph, 25 mph]
rpm 1390, 1890
HC - 119, 28
CO - 0.49, 0.03
NOx - 1627, 412
Dilution - 13.8, 14.2
CO2 - 13.3, 14.2
O2 - 1.9, 1.1

Test 6 - removed 8 degrees of timing; held 1st gear shift
[15 mph, 25 mph]
rpm 2359, 1788
HC - 61, 34
CO - 0.24, 0.06
NOx - 813, 556
Dilution - 14.2, 14.3
CO2 - 14.0, 14.2
O2 - 1.4, 1.2

> I don't think you will pass with out cats.

Looking at those numbers it appears that I don't have much
much hope of passing without a cat-con.

> Besides if you get caught
> driving with out one its a Federal crime not something to be taken
> lightly.

That cat-con that is on the car right now is empty, so it'll at
least pass a visual test.

I may try raising the e-fan turn-on temp, and take out
some more timing, but I sorta doubt it will work.

I don't want to spend a lot of time messing with it, because I
know I can bolt-up the cat and have it pass.  I was just curious
to see if I could get it to pass without the cat.




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