Those with N2O

[ToddOH]

What are you using to retard timing (if anything) when on the bottle. I'm thinking of adding N2O soon. My PCM is programmed for more timing and I would like to keep it that way. Tbyrne has the Timing Tuner that seems like a good idea. Is anyone using it? Or is this not really a concern?

[superman]

I was going to ask that same question.Mine has pcmforless tuning.i hope to have nos in a couple of weeks.keep me posted on your progress on your nos kit.

[BigTex]

I have a question for you: How much timing are you seeing at WOT? If its low 20 degrees, then I wouldn't worry with any timing trickery. If you see 26+ degrees, you might want something. That timing device looks pretty slick.

 

That being said, I have my timing set pretty high (26-28 through a run), and I normally spray a modest 100 shot without reducing timing. Its too much trouble to change the tune most of the time. If I'm planning on a larger shot at the track, I'll set the timing for 4* lower.

[PCMFORLESS]

The timing tuner is a great device and we have used it on customer cars before and it works great. I am working on an IAT tricker box to work with the PCM and initial test look promising for pulling timing with the PCM, but I am waiting to finish up my N20 install and verify it works properly

[mwalls54]

i have it, just havn't had time to put it in and also waiting for efi live to get here.

[zippy]

very interesting. it never even crossed my mind to use the iat readings to back off the timing. hmmm.

[wmcgarva]

Pardon and old fellas lack of knowledge on acronyms, is the “IAT” tricker on of the units that goes in series with the crank sensor??

[BigTex]

IAT = Intake Air Temps

 

What PCM is talking about is fooling the pcm to think the air is a differnet temp to get it to put out a higher (or lower) timing value.

 

mwalls - You'll love EFI life. It will give you lots to do adn data to look over in the evenings.

[deezel]

There are a couple of tricks that could be used to change the timing without having to reprogram the PCM.

1) Resistors for the IAT sensor;

2) use the knock sensors to intentionally reduce timing;

3) or tapping into the timing retard signal from the BCM to the PCM.

 

The third option intrigues me because I haven't seen anyone doing it, but it seems to be the ideal way to retard timing without tricking any of the useful sensors. We probably don't want the ABS system pulling timing anyway, right? So it seems like you could disconnect the BCM timing retard signal to the PCM and replace it with a switched signal to the PCM to reduce timing for nitrous use.

 

BigTex, have you heard of anyone using the BCM to PCM retard signal wire?

[mwalls54]

Well i installed the timing tuner box and it does work

[BigTex]

deezel - no I haven't, but I am definitely interested. I've been relying on the knock sensors to pull some timing when it needs to. But I get such random knock events, I don't really know if its ever false or real.

[deezel]

BigTex, I don't have 2003 service manuals yet, so I'm not sure if the wiring is the same as the 2000's. It looks like there is one wire that goes from the BCM to the PCM to command timing retard. Seems like you could tap into that wire and apply a signal to it to activate the retarding ( ).

Anyway, I think the tricky part is that you would have to turn on some of the TM tables in Edit in order for this to work. Maybe the %tq reduction vs timing table, or maybe the TCS retard?? Not sure...