I would be careful of part throttle timing advance and as you'll see in these charts afr is strongly correlative to all 3 variables.







These three charts should get you there, but I can't verify the absolute credibility of the information on them since I can't source the original publications.

 

Thanks for the charts, I have used these before, and its good to have that info on the forum. It is interesting on the charts to see that what they show at 14.7 is just about exactly the nox reading that he had, right in the 2000 range, but they will only allow 800. E85 requires more fuel to run properly so I would assume to pass smog as well? The part throttle is where we pulled the timing from, also they check your timing at idle so I set it to 10 because you only get 2 degrees of error and you fail, however they dont check it once they put the car in gear on the dyno and start running the test.

 

My best guess would to drop cruise AFRs to around 13:1. Light off the cat in a massive way before you get there, pull timing, and pray. This will raise HC by a little, but gets your nox down. Can you post all your numbers, maybe we could play a numbers game to optimize it?

Also, I don't think your going to do it without EGR connected and operating. You need the recirc!

 

Cool thanks for the help, Ive been doing even more searching and finding new 3 way cats pulling that much nox out, I thought he had a 3 way but maybe not from the numbers and what I have seen else where leads me to believe that it is a 2 way on there now, which does nothing for nox.

 

Passed, I actually ran it rich, about 13.2:1 and pulled timing down to 10 in the test range and it passed.

 

Awesome man congratulations!

 

Well Im glad it wasn't my car, I was just helping a friend, just wanted to share the info with the cali people so they can pass as well. I found that the cat was very efficiently at taking the co and hc out so I was able to run richer to bring down the nox significantly, but not enough, thats when I pulled the timing down to nothing and it passed no problem.

 

Definitely makes sense, I'll take it down in my notes for my adaptronic users. Thanks for reporting back.

 

holy. Now, will I be able to pass with a built engine + AF setup + E85 later on is the question.

 

Thanks for sharing this info. It will come in handy for CA folks!!

 

I think a low comp built motor would have less trouble passing the nox than a stock fairly higher comp motor.