Fuel pump sizing

[Paul_G]

What do you have for the rest of the system?

The fuel pickup in the tank has a 3/8" line on it. They ran 3/8" hard line from there to the fuel pump, after the fuel pump to a Fram canister style fuel filter, and up to the fuel pressure regulator, all 3/8" hard line.

I see it says 1:1 boost/vacuum ratio. I would personally assume it maxes at 15 psi as carburetors don't run over 7-8psi. But I'd call Aeromotive to confirm.

Aeromotive said that regulator is the one to use. The 3 to 15psi rating is at idle. Boost is 1:1 from it's base setting and on up.

As for the original problem of falling flat on it's face after 5 seconds of wot boost, Both the fuel pressure and boost drop off at the same time. Chicken or the egg, which came first?

I am seeing just over 15 pounds of boost before I let off the gas to not let the engine go lean. I think it still points to the fuel pump I have now. Might be able to make enough fuel pressure, but can not keep up with the needed fuel flow only putting out 50psi. half of what I am told I need. Hence pressure drops off.

I called Holley and Aeromotive, both stated I need a pump that can output at minimum 100 gph. Both stated I need -10 size fuel line. That is a 5/8" line. What about the 3/8" line at the fuel sender? The return line is also only a 3/8" line. They said make that -10 also.

I am leaning to the dual motor Holley 12-1200 pump. Outputs 130 gph @ 80 psi. I can stage the two pumps so it is not constantly recirculating fuel. First pump on all the time, second pump comes in off the same pressure switch that currently turns on the methanol injection when in boost.

For what it's worth, cruising down the road today doing about 45 mph, going wot the rear end got sideways, very loose very fast. This is going to be a fun car when it is all sorted out.

 

[Sweet5ltr]

The fuel pickup in the tank has a 3/8" line on it. They ran 3/8" hard line from there to the fuel pump, after the fuel pump to a Fram canister style fuel filter, and up to the fuel pressure regulator, all 3/8" hard line.



Aeromotive said that regulator is the one to use. The 3 to 15psi rating is at idle. Boost is 1:1 from it's base setting and on up.

As for the original problem of falling flat on it's face after 5 seconds of wot boost, Both the fuel pressure and boost drop off at the same time. Chicken or the egg, which came first?

I am seeing just over 15 pounds of boost before I let off the gas to not let the engine go lean. I think it still points to the fuel pump I have now. Might be able to make enough fuel pressure, but can not keep up with the needed fuel flow only putting out 50psi. half of what I am told I need. Hence pressure drops off.

I called Holley and Aeromotive, both stated I need a pump that can output at minimum 100 gph. Both stated I need -10 size fuel line. That is a 5/8" line. What about the 3/8" line at the fuel sender? The return line is also only a 3/8" line. They said make that -10 also.

I am leaning to the dual motor Holley 12-1200 pump. Outputs 130 gph @ 80 psi. I can stage the two pumps so it is not constantly recirculating fuel. First pump on all the time, second pump comes in off the same pressure switch that currently turns on the methanol injection when in boost.

For what it's worth, cruising down the road today doing about 45 mph, going wot the rear end got sideways, very loose very fast. This is going to be a fun car when it is all sorted out.

You're going to have to step into the big boy fuel systems ("big money"), not like you aren't already accustomed to that with a Procharged HEMI. You'll need at least a 1/2" fuel line for the feed. Return line is typically larger on FI applications to reduce strain on the fuel pump. I would get some kind of variable / fuel pump speed controller, as race pumps are not the most reliable in a street car application. Fuel cavitation & running lean, not great under boost. Another friend runs a liquid cooler for the fuel (along with a pump controller). He had some issues in warmer weather, which that cured.