shut down via HP Tuners when too lean

[1DangerousV6]

arthansen brought this up in another post..using HP Tuners to shut down the nitrous system if it goes too lean..how would you do this with HP Tuners?? thanks [img]smile.gif[/img]

[arthansen]

You will need the Enhaced Input Output option from HP Tuners and a Wide Band O2 sensor. You can set up one of the outputs to send a signal if the AFR gets too high. Then have the output open a normally closed relay that is wired into the nitrous circuit.

This would be the best way to wire it because if you do not have the laptop, the nitrous would still work (but it would not shut dowm if too lean). If you were always going to have the laptop, you could use a standard autmotive relay which is normally open. If anyone is realy thinking about this, I can make up a wireing diagram and post it here. I will also figure out how to set up HP Tuners outputs.

Just let me know.

[1DangerousV6]

what about the fuel pressure safety switch?..doesnt that do basically the same thing just using fuel pressure instead of A/F ratio?

[arthansen]

Yes. The AFR system would work just like the FPSS except it would protect against lean insteed of low fuel pressure.

One other option would be if you wanted to shut down above 14.7 you could use the stock O2 sensors and HP Tuners. The stock O2s will not give you AFR but they will tell you if you are over 14.7. However, I do not want to be any where near 14.7 on the juice. That is why I think you would need a WBO2 sensor.

The WBO2 watches the AFR, HP tuners compares it to what you want max to be (13.0) and if you go over it, HP Tuners tells the relay to stop the juice. Pretty simple actually.

[Pewter2K1]

I would want to shut down way before 14.7

I never saw about 10.1 when i was spraying, I could have used the tuning to lean the crap out of it...