dkeers

From http://www.gafba.com/articles/article.asp?tid=5 :

"When talking about bottle pressure, the goal is to try and finish the run above 750psi. Why? From zero to 760psi, mass flow of nitrous increases as pressure goes up numerically. From 760 to 865 there is a very small change, and above 925 there is an enormous decrease in mass flow. How does this translate to the track? Well, if you started your run at 925psi, as the pressure drops, the mass flow will increase until getting below the 760 point, at which time mass flow would begin decreasing. With excessively high or low pressures, you will run rich in your nitrous/fuel mixture. Throw the 1000 to 1100 junk out the window and pretend you never heard it. For a 1/4 mile run, start around 950 psi and purge the kit two or three times. For 1/8 mile, start at 900 and give it one good purge."

I have never heard this before. I always thought that flow will increase with pressure. Common sense (and all of the physics I have had so far) tell me this isn't true. What do you think?

Dustin

RacinLT1

well from my experiance,as the pressure goes down,so does performance.
Also,from what every Nitrous Rep and Tuner i talked too,they all agree more pressure is better (to a point,depends on manufacturer's system).
i ran 1050psi when i sprayed,end of the run would be in the 900's. if i sprayed when i only had 900psi to start,the car didnt run as good.

dkeers

Thats what I thought. I can't figure out why or how performance would decrease with a higher pressure.

12Second3rdgen

It just doesnt make sense... EFI guys running 40+ PSI of fuel pressure dont use larger fuel jets than guys with 6 PSI carb setups...