if my goal is 400 whp is using a walbro 255 fuel pump as my only fuel system upgrade ok( obviously excluding injectors)? stock rail stock lines ok to use for this type of power? and what if im looking to reach 500 later? is a 255 still gonna work their?

if not what type of fuel pump / fuel system setup should i be looking into

 

400 is fine...a few people have made 500, but that's pushing it. I would really spend the extra now if that's where you want to go!

 

great thanks for the advise, ill do some searches to find what step further i should be taking ;-)

 

You will be fine with just a Walbro 255 pushing 400whp on gas... its still well within its capability.

I have previously ran just over 500 wheel on stock lines and a single walbro. Taken things a step further now though.

 

A few people? I dont know anyone on the planet that has maxed out a 255hp prior to 500whp, they should be good for 600whp and some have made more.

Wiring in a relay powered by your Alternator or Battery is crucial to getting the most out of a 255hp...

 

what exactly do you mean by wiring in a relay for it?

 

What he means is run 10 gauge wire from the battery back to the fuel pump. use the power wire from the fuel pump and wire in a relay. when the stock wire powers up that will trigger the relay and gve you power from the 10gauge wire and flow more current to the fuel pump vs the stock 14 gauge wire. this will allow the fuel pump to run full out with a bigger load on it and not cause a lean condition from lack of power.

I know in my car i have a walbro 255 on stock wiring and when i turn my signal lights on when my headlights are on i can hear the fuel pump bog up and down. i plan on running a bosch 044 between my fuel filter and fuel rail so stock wiring is fine for the walbro for me but if you want all you can get out of one then 10g wire is the best thing to do.

 

is there anyway we can get some pics up for reference? i was under the impression that installing the walbro required no wiring and its location replaced the stock one's?

 

theres tons of threads , just use the search. I know I saw one last week

 

It doesnt require wiring, it was already stated in this thread to get the most out of the pump you need to run a simple relay off your battery or alternator triggered by the stock pump power wire.

I dont have the pics on hand, this has been covered a dozen times and I have found the info before several times searching for it on here, search for a thread created by " full blown " about their dual pump hanger I know the info is in there.

I will never forget the sound difference my 2 255hp's made when I wired them with relays, those things screamed!

 

installing a walboro doesnt require new wiring and its location does replace the stock one. they are saying if your pushing out more power than normal ex. 500whp then you should wire in a relay with 10gauge wire but if you are not even close to 500whp you are fine with stock wiring and just replace your stock fuel pump with the 255lph

 

I had to rewire just only ~350hp @ crank. I had only 10-10.5v when boosting. Walbro flow drops very much with low voltage. Rewiring is cheap and makes big difference in reliability.

 

i had rewired mine and around 450 is was leaning out still. not sure why. so i just put a jegs 255 in the stock line before the fuel rail and used it as a booster.. worked fine. pushes plenty of fuel now.

 

if you had only 10-10.5 volts then you have another issue its not the pump its your power delivery, probably a bad main relay

 

^^^ I agree, I never see below 14v at any point, normally 14.1-14.5 even WOT

 

Main relay was losing 1v, i measured that before and after. I have my battery in trunk...

 

What kind of relay? Bosh 12v 3 prong? or 4 prong?

 

40amp 3 prong is all you need.

 

Where do you find 40 amps at? Locally I can only find 30amp relays

 

I had ran as much as 620 whp on stock rail, stock lines and a walbro 255 in our s2k
1000cc precision injectors were pretty much at 100% duty cycle though and static fuel pressure was raised 5 psi to get enough fuel but hey it worked..