# Nitrous Oxide - How to set up a/f shutoff?

View Full Version : How to set up a/f shutoff?

pHEnomIC
06-05-2009, 12:45 AM
Ok I ran through my setup to make sure all my spray stuff is working correctly.

Right now i have torquer v3, full boltons, racetronix, green tops, HSW wet plate kit, tr-6s.

I just put a warmer in and have all the safety stuff.

I am running 12.8 a/f and 23* timing n/a.

I have the recommended jets in for the 75 shot. The timing on the 75 shot is 20* and whatever fuel it adds itself on top of the 12.8.

What should I aim my a/f to be and how should i set up my a/f shutoff? I believe i can set rich cutoff, lean cutoff, and time to cutoff in tenths of a second.

Whats the best rpm to start the spray? I think i have it set for 3500 right now.

Im gonna learn to read plugs to fine tune things.

pHEnomIC
06-06-2009, 03:27 PM

NVR_SPDS
06-07-2009, 02:36 PM
Hit up one of the HSW guys on here, theyll be able to lead you in the right direction.

pHEnomIC
06-07-2009, 10:36 PM
OK so I have a p series nitrous gauge with the a/f shutoff and a plx wideband.

I have a harris speed works wet plate kit up to 150 shot.
Ive been told my a/f should be between 11 and 12.5.

I see the gauge's formula for analog in is a/f=2*volts+10 and the plx gauges output formula is a/f=2.5volts+8.75.

I calculated it out and it looks like the plx will give off 1.5 volts for 12.5 and .9 volts for 11.

So does that mean i should set my a/f cutoff at 11.8(.9v) and 13.0(1.5v) on the gauge and then make the delay 3/10s of a sec.

Or should I set it up differently?

Rick@HSW
06-08-2009, 10:08 AM
OK so I have a p series nitrous gauge with the a/f shutoff and a plx wideband.

I have a harris speed works wet plate kit up to 150 shot.
Ive been told my a/f should be between 11 and 12.5.

I see the gauge's formula for analog in is a/f=2*volts+10 and the plx gauges output formula is a/f=2.5volts+8.75.

I calculated it out and it looks like the plx will give off 1.5 volts for 12.5 and .9 volts for 11.

So does that mean i should set my a/f cutoff at 11.8(.9v) and 13.0(1.5v) on the gauge and then make the delay 3/10s of a sec.

Or should I set it up differently?

Give yourself a bigger window than that for the rich end of the spectrum. Honestly, everyone's car will be set up different so there won't be any 1 program that fits everyone's needs. For starters you can try that, but I think you'll have better results opening the rich end up a little.

Rick