how much fuel pressure can i run with a walbro 255 pump?

sy445

New member
I dont know if it is the high pressure pump cause it was in my truck when i bought it.


Anyone know what the most pressure is that can be safely run with this pump? Its set at 45lbs now
 

TYPHOOL7

Post Hawk
Re: how much fuel pressure can i run with a walbro 255 pump?

i think 40 is where it should be, that doesnt sound too outrageous depending on ur chip/tune, why do u want to run more psi? Do you have enough spark and air for that combustion?
 

sy445

New member
Re: how much fuel pressure can i run with a walbro 255 pump?

I might be topped out w my injectors. Not sure. I have 50# and a walbro. From what i read 500-550 horsepower is around max for that power. I know im approaching that if not close. I dont plan on trying to push any more fuel cause ill be spraying alky but it could be alittle bit richer at full boost for pump gas tune. Just seeing if I can get away with that safely before upgrading the fuel system or injectors
 

JSM

Active member
Re: how much fuel pressure can i run with a walbro 255 pump?

depends how much boost your running also, remember it will add 1psi for every pound. So if your base is 40 and 20psi boost, you have 60psi spraying.

I would say you can run up to 60psi base. Try 50 first. At some point you may need another pump though. Your getting real close on a single walbro HP wise.
 

EcSy#2671

Si vis pacem, para bellum
Re: how much fuel pressure can i run with a walbro 255 pump?

I'm running 56psi with a 255 and it is running fine.
 

James Thomas

"NO CLASS"
Re: how much fuel pressure can i run with a walbro 255 pump?

Don't forget that as pressure goes up (so does heat and amp draw)..... flow goes down. Saw a Mustang guy one time with 70+ psi base on a boost referenced Vortec regulator install. His rail pressure was over a 100psi under boost and just couldn't figure out why he was still lean and popping head gaskets like my daughters PEZ dispenser :rotf: .

_______
James
 

Tooky

Serious about performance
Re: how much fuel pressure can i run with a walbro 255 pump?

How fast is your truck? I think some Syclones have gone at least 11.0s with the single Walbro. With alky you can go further. You can tell if you're out of fuel when you keep raising the fuel in the chip and the wideband continues to read lean at high boost.
 
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