‘97 5.7 build with 0411 swap fuel pressure issues…inline fuel pump questions

[97SWBCHEVY]

~20 years ago I worked on a bunch of GM fleet trucks and vans that had a Ford in-line pump added to the frame. The logic was simple as to why when I started asking questions. The older GM pumps would start to lose pressure long before they quit working entirely. The Ford pump for some reason lived a lot longer the way they were built. The Ford pumps did not like pulling fuel. The Ford pump took some of the stress off the in-tank pump allowing it to live a much longer life. The Ford pump was easy to access and change. It was a 10 minute replacement vs dropping the tank. My 1983 G20 van is still setup the same way. EP381 in the tank and a Ford pump on the frame rail. It was 100% reliable for 8 years of driving.

The newer GM replacement Delphi pumps seem to live well now so it is really not needed unless like the OP the system needs to run at as much as 80-90 PSI while the engine is in boost with a supercharger. Some of those older supercharger kits had a rising rate FMU, for every 1 psi of boost, fuel pressure was increased at either a 2:1 or 4:1 ratio. A 4:1 ratio on an engine making 10 psi of boost would put the fuel pressure at 98 psi if the base pressure was 58 psi and a 2:1 would be 78 psi. Even with a stock regulator the fuel pressure is going to increase 1:1 with boost pressure. An old factory style spider ran at 66 psi, 10 psi of boost would have the fuel system running at 76 psi. The volume of the stock replacement in tank pump would drastically fall off at that pressure without the in-line booster pump.

~20 years ago I worked on a bunch of GM fleet trucks and vans that had a Ford in-line pump added to the frame. The logic was simple as to why when I started asking questions. The older GM pumps would start to lose pressure long before they quit working entirely. The Ford pump for some reason lived a lot longer the way they were built. The Ford pumps did not like pulling fuel. The Ford pump took some of the stress off the in-tank pump allowing it to live a much longer life. The Ford pump was easy to access and change. It was a 10 minute replacement vs dropping the tank. My 1983 G20 van is still setup the same way. EP381 in the tank and a Ford pump on the frame rail. It was 100% reliable for 8 years of driving.

The newer GM replacement Delphi pumps seem to live well now so it is really not needed unless like the OP the system needs to run at as much as 80-90 PSI while the engine is in boost with a supercharger. Some of those older supercharger kits had a rising rate FMU, for every 1 psi of boost, fuel pressure was increased at either a 2:1 or 4:1 ratio. A 4:1 ratio on an engine making 10 psi of boost would put the fuel pressure at 98 psi if the base pressure was 58 psi and a 2:1 would be 78 psi. Even with a stock regulator the fuel pressure is going to increase 1:1 with boost pressure. An old factory style spider ran at 66 psi, 10 psi of boost would have the fuel system running at 76 psi. The volume of the stock replacement in tank pump would drastically fall off at that pressure without the in-line booster pump.

Hey Buddy…this is the inline pump I went with…do you think this one would/should be okay???
Shane

Fuel Pumps, Electric, In-line, External Mount, 190 lph, 85 psi, 12V, 10mm x 1.0, Female Thread, Inlet and Outlet, Steel Housing…

 

[L31MaxExpress]

Hey Buddy…this is the inline pump I went with…do you think this one would/should be okay???
Shane

Fuel Pumps, Electric, In-line, External Mount, 190 lph, 85 psi, 12V, 10mm x 1.0, Female Thread, Inlet and Outlet, Steel Housing…

If it actually moves that 190 lph at 85 psi should work out well even with the supercharger. The problem I have run into is the advertised flow rate will often be at 0 psi. I would contact Holley and make sure it is 190 lph @ 85 psi.

 

[L31MaxExpress]

I opened the pump on Holleys site. Probably get you by now, but it will not be enough with the supercharger. That 190 lph rating is at 40 psi.

 

[97SWBCHEVY]

I opened the pump on Holleys site. Probably get you by now, but it will not be enough with the supercharger. That 190 lph rating is at 40 psi.

Thank Ya Sir…