Is a Walboro 255 good enought for a 250 shot with no Booster pump or anythinglikethat?

 

anyone??

 

What is the "total" HP of the engine..... NA + N2O? Only with that info can you estimate the fuel requirements, and compare it to the flow curve for the pump in question. It would also be necessary to know the operating pressure for the fuel system if its anything other than 43.5psi.

 

As long as you have the 255 in line it will only flow as much as the 255 can provide. THe booster pups such as the T-rex will add PSI but the system can only flow as much as the smallest pump can provide. As for if the 255 is enough pump it depends on what your total HP is. I think the 255 is good for around a total of 700CHP, do not quote me on this I am going off a poor and sometime troubled memory .

 

Im not sure exactly wht fuel pressure Ill be reunning at yet. the car should make 425 WRHP NA and up tp a 250 shot is a shot as I will ever spray it.

 

What is the flywheel HP.... that's what determines the fuel requirements??? Making assumptions on your drivetrain losses, and allowing for a 20% return capacity at max flow, you would probably be looking at about 190lph for the NA portion, and maybe 130lph for the N2O, for a total of 320lph. A Walbro 255 will not be enough.

I run a 205lph Bosch pump in the stock tank location for "NA" power, similar to what you are looking at, and have a 2nd 205lph Bosch pump off a sump on the rear of the tank. The second pump only comes on when the nitrous system (300HP) is armed. The two pumps flow in parallel, merging in a "Y" right in front of the fuel filter.

You can increase both the flow and pressure capability of a fuel system by putting pumps in series. The actual flow vs. pressure curve will be a summation of the two individual pump curves, and each one will reach an equilibrium point at which both pumps flow the same, but contribute a portion of the total pressure based on their individual flow curves. Since the smaller pump is now operating at a lower differential pressure, it is capable of flowing more capacity than when it was supplying the full pressure of the system.

I wouldn't recommend series pumps as a way to increase system capacity, but it is possible. Best used for systems that also require higher pressure, like a blower using an FMU, or a dry nitrous system like the NOS 5176.

 

How do you keep the fuel from back feeding?

 

Kinsler #3096 bubble tight check valve, -6AN.