? about o2 corr on nitrous pass

[van460]

i have made serial passes on nitrous and never had a problem but my o2 was corr about -15% to get to 11.5 af ratio, so i decided to take out the extra fuel to get the o2 corr at as close to zero as poss. well when i did i burnt some plugs the o2 did not corr to add in the fuel actually it was -3.9o2 corr and burnt plugs i have the program to corr up to 25% if needed what do you think happened?

 

[bobc455]

Van,

My opinion is that you should completely disregard the WB O2 when running nitrous. And that means running in open loop.

First step is to get your VE table accurate as possible. That way you don't need closed-loop.

Somehow you should maintain a consistent bottle pressure (pressure switch, watch the gauge as you heat it, whatever), and then read your spark plugs and adjust your fuel delivery accordingly.

Leaning out the engine is a very dangerous game, and I have the machine shop receipts to prove it. Heed my word.

-Bob Cunningham

 

[Craig Smith]

Nitrous can definitely affect the WBO2 reading. Small to average shots typically aren't too much of a problem, but the more nitrous you spray, the more likely you are to be looking at false readings. There's always some amount of unused nitrous that makes it out the exhaust, and the bigger the shot, the bigger this amount is. Kind of a "diminishing returns" deal. And nitrous oxide simply isn't a substance that O2 sensors are designed to deal with very well.

I would work off the spark plugs before I would work off the O2 sensor readings for nitrous tuning. As for what happened, I would have to say that if the wide band was still pulling fuel out, you were richer than the target a/f ratio in the N2O parameters screen. Were the a/f readings on the run that damaged the plugs similar to readings from other good passes?

 

[van460]

ve table

hey bob refresh me memory on the ve table is that a table i look at it does not ring a bell. i would like to not run in closed loop if it would perform better. is there a way to contact you other than e-mail and chat bourd for further questions?

 

[bobc455]

Sure, I'll email you my phone number.

-Bob