What fuel pump should i get?
This depend on many factors but we bring them all up here to make you confident choosing the right fuel pump for your application. Type of fuel used, flow, in-tank or external, backpressure, accessories needed.
What type of fuel can a fuel pump handle?
Most fuel pumps can handle regular pump gas if nothing else is stated. But when it comes to race fuel and ethanol you can run in to some problems. Mainly because the pump gas has a natural like "lubricant" for the fuel pump internal parts which race fuel and ethanol do not have.
Now you have two options. Add some lube like additives or use a fuel pump made for ethanol.
And remember. There is a big difference of a fuel pump made for ethanol and one that can handle ethanol but not made for it.
In tank or external fuel pump?
What mailnly decide if you're going to use external or in-tank fuel pump is the application and mounting possibilities. The function is the same as long as the specific pump you're looking at can handle the power needs.
If you feel better off with a external pump because you have a fuel cell limit you to this installation then go with the external fuel pump. But if you run the original fuel tank then you might consider the internal ones because of the avalibility of high performance replacement pumps.
How much power can the fuel pump handle?
Deciding what pump to use to handle you power goals need some simple calculations. Example:
4 x 900cc/min injectors at 3 bar.
900 x 4 = 3600cc/min (3,6L / min)
3,6 * 60 = 216L/H (fuel pump capacity at 3 bar back pressure)
If yo use 1 bar of boost and the injectors deliver 960cc at 4 bar
4 x 960cc/min injectors at 3 bar.
960 x 4 = 3840cc/min (3,84L / min)
3,84 * 60 = 230,4L/H (fuel pump capacity at 4 bar back pressure)
Be sure to check the fuel pump flow at your calculated backpressure.
Fuel pump back pressure
Fuel pump names are often given by the fuel flow they can deliver at 3 bar. This only give you an indication of what you need. Compare it with a bicycle. With a high gear you can go faster = pump max flow. But with this higher gear/flow it's harder up hill = backpressure.
Be sure to check out the fuel pump flow at your calculated back pressure. 3 bar base pressure plus 1,5 bar of boost gives you 4,5 bar of back pressure. this is what you need to look for.