94droptopz

ok here goes. if i buy a nx kit for an lt1 somebody ran on a stock fuel pump how do i know what jets i need to run with a 255lph fuel pump? i assume the jets have to be different or it would run really rich when i hit the juice correct? thanks
Rob

drop top steve

You should still have oem fuel pressure at the rail, use nx recomended jetting. If your fp is higher than oem then maybe drop down one size.

94droptopz

is there not a correct way to do this for sure? surley im not the first person with an upgraded fuel pump to run nitrous. the way i figure it is if your running a 100 shot on a stock fuel pump then you upgrade to a 255lph pump it has to throw off your nitrous to gas mixture and make it run very rich. anyother opinions guys??? thanks

dabear95

No, fuel flow is regulated by the fuel pressure regulator. If a fuel pump is pumping 100 gallons a second while under the current conditions the engine only uses one gallon a second ( ) the rest will be returned to the gas tank via the return line. The fuel pressure regulator will maintain the correct fuel pressure in the fuel rails by controlling how much gets through. The rest gets sent back to the tank.

If you used too big of a shot on the stock fuel pump, you might not have enough fuel so there may not be enough to send any back to the tank. That would be a problem.

With your new fuel pump, under most conditions, it is just flowing more fuel back to the tank. But there is more in reserve for when you need it, so that your fuel pressure will remain high enough for proper operation.


I hope that made sense!
Jason

94droptopz

ok so if im running a 255lph fuel pump on a 500 hp motor with a 100 shot,under normal load most of my gas will be returnd to the tank but when i get on it the engine will use the extra gas correct? so what stops the extra gas from flooding the nitrous setup?

if your running say a 31 fuel jet for a stock fuel pump(cause thats what nx calls for) when you stomp it,it will get the correct fuel pressure flow.

now im running an upgraded fuel pump with upgraded injectors and programming to fit (more fuel to motor) when i stomp it,and the nitrous kicks in, it will flow more gas through the fuel jet (31)making it run rich, correct? maybe im wrong but thats the way it seems to me.

it seems to me that if the 31 jet is correct for a stock fuel assembly then an upgraded fuel assembly should have a different jetting. tell me if im wrong cause im damn sure confused
thanks
Rob

drop top steve

The fuel supply for the n2o is on the pressure regulated side of the system. A bigger (more gph) pump does not change pressure on the regulated side.

94droptopz

so if i run my nitrous to the shrader (spelling?) valve on the fuel rail after the tuning and larger fuel pump it will not affect the amount of fuel going to the nitrous? sorry for all the questions but i really want to be sure about this. thanks for the help
Rob