customblackbird

iTrader: (2)

I haven't seen any actual numbers of flow tests of the two pumps or any hard data. I recently dropped in a stock 5.3 with 12psi supercharger in my 87 TA. I replaced my sumped stock tank with a non modified sumped tank and swapped in an Aeromotive 340lph, mainly bc of costs ($110) and the ability to support my expected hp and not overpower the stock sized fuel lines at the tank. (not easy to modify due to space). With that being said car ran beautifully with 58psi base fuel pressure and 12psi boost into the Aeromotive boost referenced regulator (total of 70psi fuel pressure) on 93 pump gas. But now thats never enough and I'm throwing in ported heads and a custom cam that should net me 100hp+ so I'm prob going to run out of fuel pump. So I did some research and wanted to stay single pump in tank and pulled the trigger on the walbro 450lph and an install kit.

My only worry is the 5/16" return line in the stock tank which is about 3ft-4ft long. Feed line is 3/8" hardline for the same 3ft and then -6an to the rails.

So I went and figured out real world flow data of the two pumps and compared them and figured out the hp rating at different fuel pressures.

My Data logs suggest 525-550hp at the crank at 70psi fuel with 72lb bosch injectors. The new combo can make 650hp+ at the same boost and fuel pressures. The Aeromotive 340 only flows enough to support 580hp at 70psi vs the 845hp the 450 can support. My only concern is the fuel pressure short section of 5/16" return line. I have thought about running lower 43.5psi as my base fuel pressure but FIC recommended I dont as the LS1 style 72lb bosch injectors have a much better spray pattern at 58psi.

This info is for others, hope this helps.

Fuel PSI / Walbro 450lph @ 13.5v / Aeromotive 340lph at 13.2v
40psi / 430lph @ 1025hp / 315lph @ 750hp
50psi / 405lph @ 965hp / 291lph @ 700hp
60psi / 381lph @ 907hp / 269lph @ 640hp
70psi / 355lph @ 845hp / 245lph @ 580hp
80psi / 328lph @ 780hp / 220lph @ 525hp

callys

iTrader: (2)

I am making the same pump upgrade for the same reasons but I wouldn't worry about the lines.

Terminator cobras have 5/16 feed and return.

LQ4 trucks have 5/16 return and if you look at the perfomance truck boards their stock lines have been pushed to 700+rwhp.

The zr1 has a 5/16 return as far as I can research

customblackbird

iTrader: (2)

Yea, thats what I have been reading as well. The 3/8" feed supossidly can support 1200hp on its own and the return is allowed to be equal or 1 size smaller.

Just got my pump the other day, doesnt come with submersable hose in the install kit. so now I hope my Aeromotive stuff with swap over or that I have enough of left overs to make the connection.