Going over my diacom files from yesterday's test runs with the 50 shot I'm wondering what is going on.
Jets
N2O : 35
Fuel : 20
Pressure: 750psi
The nitrous hits at 3400 RPM. Once the car hits 4800 RPM the oxygen sensor millivolt readings go from about 850 to about 100 or lower and stay that way. If I shift to the next gear at a point that drops me below the nitrous activation the same thing happens again. Kicks in at 3400 and stays about 850 and then once 4800 hits it drops like it fell off of a cliff again. Within one frame of data's time it does this.
I am wondering if the single wire (non-heated) O2 sensor on my car is getting flushed cold. The car runs rather rich to begin with, and the bottle was only at 750psi so it would of been running even richer under that condition I would assume also.
For the moment I'm just nervous because I don't want the car running that lean if it is a true reading, but in the same breathe I do not believe that it is a true reading. I guess I will have to dig out the heated O2 I have around here somewhere and install that into the collector and also get the wide band bung welded in.
For what its worth the O2 sensor is still up in the #7 primary only a few inches from the exhaust port. I have yet to relocate it into the collector and switch to the heated versin. Car pulled hard and clean over 6000 and the window switch is set to kill the juice at 5400.
Or could it also be my stock volume fuel pump not being able to hold up in the higher RPM. Must... get... FP gauge on.
Be safe and tune it on a dyno with wideband A/F readings.
Thats in the game plan soon, I wanted to try it yesterday to verify the electricals were working. I didn't want to show up at a dyno session and waste an hour tracking down a wiring bug.
Re: Can nitrous extinguish single wire O2 sensors? (scorp508)
You are still running the stock L98 pump with a modded engine and nitrous? Man, that would be the first thing I would fix! Get at least an LT1 pump in there. Heck, I am running an L98 pump with my cross-fire and am planning on switching to a Walbro when I get the "juice" on there. The L98 pump is in no way a good pump for 400+HP. Get a bigger one before you have problems. A Walbro is about $150-$160 for a kit. DO IT NOW! Don't starve your engine!
The L98 pump is in no way a good pump for 400+HP. Get a bigger one before you have problems.
My opinion differs somewhat on that. Here is a pull done with a stock L98 pump, 22# injectors, low fuel pressure setting, and a horribly out of tune chip.
Red & Blue are the modified pulls, the other two are the stock figures.
Mod: 322rwhp / 365 ft/lb before any tuning at all.
Stock: 211rwhp / 315 ft/lb
The car now has 24# injectors and is running rich even at 6000+ now. An upgraded pump is in the plan anyways, but it just isn't necessary at this power level naturally aspirated. I'll verify if the pump is holding up to the juice as soon as the weather is good.
Didn't mean to cause an issue on it, I am just a real safety freak when it comes to fuel pressure. I personally would not trust an L98 pump with that much HP. Heck, the LT1 pump has more flow than the L98 pump and NOS ships a booster pump with their kits for the LT1. Dominic on the Cross-fire forum was having fuel pressure problems with an L98 pump at 350HP (flywheel). The pressure was dropping off at high rpms. He switched to the LT1 pump and everything was cool. JMHO
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Can nitrous extinguish single wire O2 sensors?
