I've been worried about this for a while because my car has a vacuum leak somewhere that doesn't let it idle that great on occasion. Here are my mods and the numbers (177k miles):
* stock longblock
* 160 stat
* TB coolant lines blocked
* pass side K&N breather
* stock 17-year-old cat
* Walbro 340 w/ Racetronix hotwire
* 237 FP reg
* 9" K&N behind front bumper (homemade cold air)
* Trans + w/ 3" LT1 MAF (all settings "zeroed" & base MAF on 3)
* 98 octane extender chip
* Hooker exhaust
* ported stock turbo and elbow
* 25-30% mix of xylene in tank, ~3/4 full
* adj. wastegate rod that only holds about 8 psi at WOT, solenoid vent blocked off
* drove around for about 10 min.
THC g/mi
std - 2.00
me - 1.13
NOx g/mi
std - 3.70
me - 1.06
CO g/mi
std - 32.0
me - 22.3
CO2 g/mi
std - N/A
me - 691.1
The THC and NOx numbers are better than 2 years ago when the car had less done to it, but the CO number is much higher than before. I had the stock MAF and chip, and a smoking stock turbo, for that test. Here are the numbers from 2 years ago (170k miles):
THC - 1.31
NOx - 2.36
CO - 6.2
CO2 - 574.8
Joe and Jim, all the archived emissions posts, and this section of the board in particular, helped arm me for the test, so I hope this info is helpful to someone. One thing that is confusing me - I thought my NOx would be higher using a non-EGR chip like the extender?
* stock longblock
* 160 stat
* TB coolant lines blocked
* pass side K&N breather
* stock 17-year-old cat
* Walbro 340 w/ Racetronix hotwire
* 237 FP reg
* 9" K&N behind front bumper (homemade cold air)
* Trans + w/ 3" LT1 MAF (all settings "zeroed" & base MAF on 3)
* 98 octane extender chip
* Hooker exhaust
* ported stock turbo and elbow
* 25-30% mix of xylene in tank, ~3/4 full
* adj. wastegate rod that only holds about 8 psi at WOT, solenoid vent blocked off
* drove around for about 10 min.
THC g/mi
std - 2.00
me - 1.13
NOx g/mi
std - 3.70
me - 1.06
CO g/mi
std - 32.0
me - 22.3
CO2 g/mi
std - N/A
me - 691.1
The THC and NOx numbers are better than 2 years ago when the car had less done to it, but the CO number is much higher than before. I had the stock MAF and chip, and a smoking stock turbo, for that test. Here are the numbers from 2 years ago (170k miles):
THC - 1.31
NOx - 2.36
CO - 6.2
CO2 - 574.8
Joe and Jim, all the archived emissions posts, and this section of the board in particular, helped arm me for the test, so I hope this info is helpful to someone. One thing that is confusing me - I thought my NOx would be higher using a non-EGR chip like the extender?