Fuel Pressure and Volume Requirements

[MoeJr]

On my bone stock 84 T with 12.5 psi boost and stock chip my engine analyzer program says i'll need fuel flow of 25.3 gallons an hour and 24 lb hr injectors(stocks are 28 so i am safe). Now I converted 25.3 gallons to liters and got 94.6. Does this sound right and if so I assume a new stock fuel pump will do this? Any help is greatly appreciated.

Moe :biggrin:

 

[Jerryl]

On my bone stock 84 T with 12.5 psi boost and stock chip my engine analyzer program says i'll need fuel flow of 25.3 gallons an hour and 24 lb hr injectors(stocks are 28 so i am safe). Now I converted 25.3 gallons to liters and got 94.6. Does this sound right and if so I assume a new stock fuel pump will do this? Any help is greatly appreciated. .........

If you have not yet purchased or installed the new OEM / stock pump, get a Walbro 340 from one of the vendors on this board. (DO NOT purchase off EBAY!!). That way, for about the same price, you won't need to look back and KNOW you get enough fuel.

If you decide to keep the stock pump, I would set the boost at 10 PSI to play it safe and keep it there.

 

[MoeJr]

Thanks Jerry. I did a little playing around with fuel rate requirements. I already have the pump and it is an aftermarket stock replacement. No money to get a Walbro right now. However I contacted the manufacturer of this pump. It will flow .666 gallons a minute 39.96 gallons an hour 151.7 liters an hour. Like I said according to my program I need 94.6 liters an hour so I have that covered. I kept upping my combo and this pump "should" support max 390 HP probably 350 comfortably. I didn't think that was too bad for a stock replacement pump. Of course Injector size would have to increase with fuel flow. Pressure too.

 

[bison]

You need to know the flow at 50-60 psi of pressure for your application with the stock regulator. They usually quote you flow numbers for pressures of 43.5psi. It will put out less volume at the higher pressures.

 

[Jerryl]

FWIW .......
Just installed a new Walbro 340 from FT.
· Battery measures 12.3V (Engine off) at the battery, and, slightly lower at the pump.
· FPR set at 50 PSI
· Car has the hot wire kit installed.

I measured off 1 gal exactly in a container and primed the pump through the prime connector.
Removed the Schrader valve and timed it for volume – 38.8 seconds / gal.