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Any of you guys modify the fuel rails on your high output LT1 car?
I had a problem where my walpro 285 (hellcat 140gph) fuel pump was flowing too much at idle for the small return orifice in the stock type regulator. I decided to cut the rails down eliminating the crossover and regulator, running a feed to each rail off of a remote regulator.
I saw some posts from a decade ago of folks doing the exact same thing, curious if any of you still are ?
BTW, im running the 450 l/hr pump on stock ‘93 fuel rails.
i see about 48 psi at idle (vs 38) as a result.
What gauge wire do you feed the pump with?
I did some testing a few weeks back. With factory wiring I saw voltage drop which reduced pump output. On battery power, voltage reduced to about 11.5 at the pump connector. A 400lph pump delivered 257lph at 43.5 psi. Flowed about 260lph free flow. At 12.5 volts (car running) it was a little better at 300lph.
After upgrading the wiring to 10awg, I see 13.9-14 volts at the fuel pump head. I'm running the helcat pump now which is 525 lph.
Car requires about 415 lph to be safe under boost.
I did some testing a few weeks back. With factory wiring I saw voltage drop which reduced pump output. On battery power, voltage reduced to about 11.5 at the pump connector. A 400lph pump delivered 257lph at 43.5 psi. Flowed about 260lph free flow. At 12.5 volts (car running) it was a little better at 300lph.
After upgrading the wiring to 10awg, I see 13.9-14 volts at the fuel pump head. I'm running the helcat pump now which is 525 lph.
Car requires about 415 lph to be safe under boost.
-- Joe
I run the racetronix (8? Ga from alternator to tank) relay kit.
however i reused the 16 gage wiring where it passes thru the sending unit /cut off the walbro weatherpack connector since none of it matched what was on the stock sending unit (soldering it to 14 ga wiring on the pump, using mcmaster fuel resistant shrink wrap around the solder *****).
im assuming since i have only 10” of 16 ga wiring that id be ‘ok’.
I made a bunch of posts on this, asking if anyone knew of an adapter for new turbine walbo fuel pumps to our stock wiring and all I got was crickets
called racetronix. Talked to some very stupid people who told me walbro 450 l/hr is just too big for my e85 / forced induction application
and thats what i decided to do to make it work (ie. Cut off the connectors and Solder the 14 ga pump wirings to the 16 ga sending unit wiring)
I run the racetronix (8? Ga from alternator to tank) relay kit.
however i reused the 16 gage wiring where it passes thru the sending unit /cut off the walbro weatherpack connector since none of it matched what was on the stock sending unit (soldering it to 14 ga wiring on the pump, using mcmaster fuel resistant shrink wrap around the solder *****).
im assuming since i have only 10” of 16 ga wiring that id be ‘ok’.
I made a bunch of posts on this, asking if anyone knew of an adapter for new turbine walbo fuel pumps to our stock wiring and all I got was crickets
called racetronix. Talked to some very stupid people who told me walbro 450 l/hr is just too big for my e85 / forced induction application
and thats what i decided to do to make it work (ie. Cut off the connectors and Solder the 14 ga pump wirings to the 16 ga sending unit wiring)
I did the same really, ran new wires through the sender though. 10awg, new relay, etc.
You won't get voltage drop on just 10" of wire, will be fine.
….. I have an Aeromotive 340 in tank pushing E85 to MPFI rails with an Aeromotive FPR on the return end … I ran 10gauge wire from the relay back and 12 gauge into the tank through a nylon toilet seat screw that eliminated the factory pass through connector on the fuel tank plate … so far , so good ! .....
LT1 Parallel fuel feed
