Chris@NitroDaves

Congrats Patrick... You hit around the MPH that we were talking about. I bet it was fun.

-Chris

Smokin87TA

iTrader: (183)

Congrats, that sounds like a blast.

QUASAR

iTrader: (6)

Congrats!

Do you have a specific nitrous tune that enables based on nitrous activation?

Patrick G

iTrader: (14)

Yes. With speed density, I made my PE multiplier inactive unless my TPS exceeded 95%. To compensate for a possible lean condition on motor, I added 13% extra fuel to my 90-105KPa VE tables to get them to keep me at 13.0 A/F ratio up to 95% TPS. This mimicked my NA tune as my VE tables were tuned with my PE multiplier being locked in at 1.13. At 95% TPS and above, my PE multiplier is 1.30 (adding 30% more fuel). So under 95% TPS, I'm at 13.0 AFR N/A in my 90-105KPa VE tables, then as soon as I'm at 95% TPS or higher the extra 1.30 PE multiplier kicks in. Basically, the fuel is already there by the time the nitrous hits (at 100% TPS). No delays. It hits harder than a wet shot (since wet shots can have lean spikes too).

Here's how I did it:
Let's say that my NA tune has my VE table peaking at 115% at 100KPa and 103% at 90KPA. Well this is based on my PE multiplier of 1.13. When I zero my PE multiplier for anything below 95%, it leaves the VEs on the lean side from 90KPa and greater. To compensate, I add the 1.13 back to the 90,95, 100, 105 VE numbers. Now my 100KPa VE table peaks at 130% and my 90KPa table peaks at 116%. So now, up to 95% TPS, my tune is exactly like my NA tune.

But when the TPS exceeds 95%, it adds the 1.30 PE multiplier to compensate for the nitrous that hits at 100% TPS. The 1.30 multiplier seems to work well with the .065 jet at 1050 PSI.

Special thanks go out to Geoff from Thunder Racing for giving me the idea.

Patrick G

iTrader: (14)

Video clip added:
http://guerragroup.com/PG-TxMile10-28-06_183.092mph.wmv

Reject

iTrader: (24)

sounds badass!

QUASAR

iTrader: (6)

Nice job! I have always theorized about setting something up similar to that, and wondered how it would perform. I'm glad someone finally did it. I guess as long as you stay under 95% throttle N/A you won't flood the motor with the 1.30 multiplier. What do your logs look like in terms of the instant you go wot, how does the afr react? Is there a moment where it is pig rich or is the timing of the nitrous pretty dead on. I would think even if there is a small discrepancy it would be neglegable seeing wet shots have a traditional momentary lean spike anyways and it doesn't hurt anything. But I was just wondering. Again good job on that setup.

Patrick G

iTrader: (14)

The beauty of the speed density tuning is that the fuel arrives at the same time as the nitrous. There is no lean spike. It hits very hard!

BLCK PRL

http://texasmile.com/

QUASAR

iTrader: (6)

Just thinking out loud, what about some sort of setup where when you go WOT N/A, you cap TPS voltage to whatever = 95%. And when the nitrous gets activated the tps runs thru a different circuit without a cap and can report the full 100%?

Patrick G

iTrader: (14)

That could work, but it's a lot more complicated than some of the other simple solutions out there. The best I've seen is EFI Live custom operating system 5. You get the timing retard and fuel ramp-up needed to run hard and safe with nitrous.