ocdm3 wrote:
Can you guys tell me if this holds true about nitrous tanks. Which fuel pump would be ideal for my set up?
typical engine uses 0.5 pounds of fuel (gasoline) per hour to make each horsepower. Gasoline weighs in at approximately 6 pounds per gallon. To calculate fuel consumption let me show you by example. Lets say we have a 400 HP engine (or nitrous system) and we will use the following formula:
400 HP X 0.5__ X 1 gal = 33 GPH
HP per hour 6 lb.
If you installed a pump rated at 33 GPH on a 400 HP Nitrous system the engine would experience severe fuel starvation and your wallet would cringe in "empty" pain! WHY?
There are several reasons ... However, the main reason is the way that pumps are rated. Fuel pumps are rated at "zero" pressure (also known as "free flow"). Rating a pump at zero pressure is useless because the pump will never be at zero pressure when it is operating in the vehicle. As fuel pressure increases, the fuel pump slows down and fuel output is reduced. If you use a standard "dead-head" type regulator, the pump may be forced to produce as much as 25 PSI. At 25 PSI, the actual output GPH of the pump is much less than at "free flow".
You are correct with your statement.
The good news is that quality pumps will have a more realistic output curve, which is a good place to start. What also needs to be considered, is that the pump is just 1 component in system, and each component has an effect on flow. For example, the pickup tube and type of filter used before the pump will affect flow, as well as the hose and filtration after the pump. Fittings, distribution blocks, bends in hose, and gravity will also effect flow.
The best thing you can do is flow test the assembled system as it will be used on the car.
As for your choice of pump, I'm sure a few others will have a more informed choice that I, my experience is mostly with Walbro 255L/hr pumps which work fine, but you need to keep a spare around.