Just wondering if any of you guru's are running in open loop and spraying? If so what requirements must be met to do so? Thanks in advance!!!

 

Not sure I understand the purpose of your question. Most people only spray at WOT, and at WOT the LT1 PCM does not use the feedback from the O2 sensors..... hence the system is not functioning in "closed loop". So the answer is "anyone with an LT1 is spraying in open loop." There is always the semantics issue of GM referencing the WOT operation as "enrichment mode" rather than "open loop".... a term they reserve for the cold start condition.

In general, the stock LT1 PCM remains "tuned" for the NA requirements of the engine, and the fuel for the nitrous portion is controlled externally, as is timing. You either control fuel with (wet) the fuel jet, or (dry) with some external stimulous to the fuel pressure to increase fuel delivered for each pulse width the PCM is calculating for NA requirements.

I run an aftermarket engine management system (MoTeC) and it runs "open loop" at all times. The NA A/F control is done by one program, and when the dry nitrous is activated, there is another program activated to add the fuel (and alter the ignition timing) for the N2O that is being sprayed.

Again, not sure I understand the intent of your question......

 

Thanks Injuneer!! Your advice is always welcomed. Im having some problems with the computer/sensors so i unplugged the O2's and i was wondering about spraying. If im not mistaken doesn't the computer just give the motor a certain amount of fuel in open loop regardless of the sensors? So if thats the case will nitrous lean it out? Or does it go into PE mode even if im running in Open Loop? Thanks Again To Everyone!!!