Fuel Pump Size Calculation

JAM1 · Post by **JAM1** » Thu Jul 19, 2007 12:23 pm

I am trying to size a fuel pump for my application. If i use the given scenerio:

8 injectors
flowing 115lb/hr
methanol as a fuel (6.6 lb/gallon)
70 psi

My calculation would look like this:

8*115/6.6=140Gallon/hr and 70 psi

This is a serious pump. Are my calculations correct? If so, where would i get a pump with this rating?

Would i need to use 2 pumps to get the flow rate?

TT350chevelle · Post by **TT350chevelle** » Thu Jul 19, 2007 9:08 pm

Finding a suitable pump that can support alcohol and flow the required fuel@70 psi base pressure will be expensive.Magnaflow and Weldon sell electric EFI pumps that will work or you can go to a belt drive from Aeromotive (thats what I bought for my twin turbo EFI Acadian)
According to Magnaflow, 110 gal/hr should support ~650hp, 140gals/hr should support ~840hp using 1.1 BSFC for alcohol.
http://www.magnumforce.com/store4/magna ... _notes.htm

Brad J.

JAM · Post by **JAM** » Fri Jul 20, 2007 9:08 am

Thanks for the info on the pumps and site. I thinks i am just going to have to step up and spend the $ for a pump to do the job.

It looks like you do some dragracing. Do you run a mechanical or electric pump on your dragcar? I am trying to decide but i don't know the pro/cons to either other than mechanical has parasitic losses off the crank, but if you run a electric and an alternator (which i plan to do) it would load the alternator.

Since you drag race, would you look at the post i have on this forum about PWM vs resistor to control injectors? Jean has been really helpful to informing me about the injector driver he provides which seem like they would lend to repeatability and consistiency. What do you use?

TT350chevelle · Post by **TT350chevelle** » Fri Jul 20, 2007 9:34 pm

Electric Holley Volumax (I always run an alt too) with carb and alcohol but bought an Aeromotive belt drive pump for the high pressure associated with EFI and turbocharging.I have not run the belt drive yet, the twinturbo drag car is still in the "collecting parts" stage.

Brad J.
PS: I did reply to your other post, I'm using PWM (flyback board MS V2.2) with 2.4 ohm injectors, no problems. I'm hoping MS sequential will be ready when the TT drag car is, I think sequential will be the only way to go when using 160 lb/hr injectors.