I have a '95 LT1 and a NX Wet kit. I ran the nitrous in the stock elbow and it worked perfectly. Since then, I have upgraded to a Ram Air setup with a LS1-lid intake.

Only prob is, the bellow I am now using (from a '96 vette) has way too many big ribs in it to put the NX nozzle in there safely, IMO. I would be too worried about the seal of it and about nitrous puddling in the bellow.

Can I put the shark nozzle in the lid right before the MAF sensor?

I know that this is how some people run a Dry shot in a LS1, but would gas and N2O threw the MAF mess it up?

Thanks,
Phil

 

that would defeat the purpose of spraying a wet shot. you would keep the a/f ratio optimal by adding the fuel but if you spray it through the maf too, it would add even more fuel to compensate for the increased aif flow and you would run pig rich.

 

You do not want to spray wet nitrous through the MAF. It will screw things up royally, as Dan pointed out. You need to keep it in the bellows. Why not use the Fernco 3"x3" sewer pipe connector, like a lot of us do?

Fernco Connector

 

I have a slp bellow with a hole where the sharknozzle would go.

let me know.

 

OK good thing I asked then. I won't do it.

I was thinking it would be OK because of the way I thought how these motors work. I have read that when a LT1 goes into WOT it goes into a "power enrichment mode" which is like open loop when the computer goes off tables and not sensors. I thought a LT1 only uses the MAF for air/fuel ratios in closed loop.

I have also read that LS1s do not go into this "power enrichment mode" and actually stay in a closed loop when at WOT, this is why they can run a dry shot of N2O threw the MAF and be OK, because the computer would compensate and add more fuel.

I have never seen anyone run a dry shot threw the MAF on a LT1, so this made sense to me.

Can anyone clarify this for me? The more I learn the better.

Phil

 

In a mass air LT1, the only difference between low/moderate load (closed loop) and WOT (power enrichment mode) is the fact that the O2 sensors are no longer used for feedback as to the actual A/F ratio. The PCM still reads the mass air flow signal from the MAF sensor, and calculates the amount of fuel required to reach the PE mode target A/F ratio. The PCM may still use the long term fuel corrections for Cell 15 in the PE mode calculations (depends on whether the BLM would be adding fuel or pulling it out). The only sensor that is ignored is the O2 sensor.

And, when you do spray through the MAF sensor, as on the LS1, you only spray nitrous for a dry system, not nitrous + fuel. The MAF sensor measures the inlet temperature of the air (and nitrous) flowing through the sensor, then calculates how much power it takes to keep the wires a certain number of degrees higher than the incoming air. I have seen a number like 100degF as the typical heating. By knowing the number of BTU's put into the wire with the current, and knowing the specific heat of air (BTU/#-degF), the MAF can calculate the mass flow (#/min, grams/sec, etc) of air.

When you spray nitrous into the MAF, the only reason is might throw things off is because nitrous has a different specific heat, and a different O2 content than air, so the MAF reading is no longer valid. Possibly the specific heat issues and the O2 percent issues cancel each other out... I never made the calculations.

Allegedly, the LS1 PCM is a much faster processor than the LT1 PCM, so it can react faster to the MAF data. And, I read in an article by NOS on the NOS 5177 LS1 kit that the LS1 PCM keeps the O2 sensor in the loop at WOT, but I have had a couple of LS1 people tell me that isn't true. I just know that a friend of mine runs the 5177 dry kit, 125-shot on a cam and headers stock LS1 bottom end, and runs 10.8's with 30# injectors and STOCK tuning, so it appears the LS1 PCM can respond correctly.

But.... that is a case of spraying nitrous ONLY through the MAF, and insuring the nitrous is fully vaporized before it hits the MAF. If you put the nitrous nozzle right in front of the MAF, it won't work because liquid nitrous will be reaching the sensor, and consumoing huge amounts of BTU's as it changes to a gas, throwing the MAF sensor into turmoil, and possibly cooling it below the point where it can even function.

Add fuel and nitrous before the MAF snesor and it will render the sensor useless.... the output signal will be meaningless.

I have seen a couple people on this board who oclaim to spray DRY systems in front of the LT1 MAF with no problems, but I would be extremely careful before trying it.

 

Thanks, it all makes sense now.