what kind of fuel psi

[JWaltz]

What kinda fuel pressure is safe to run I know like 70 pops o-rings but what kind of minimum is safe at full throttle

 

[java]

I leave mine set at 62 psi.

 

[JWaltz]

What do you drop to at wot

 

[Scott@All Pro Diesel]

I set mine at 55. And it don't drop but a couple psi but I run a RR.

 

[java]

It usually stays at 60-62 wot with 190/100s. I have an AD2 and a RR.

 

[lenzhotrod]

70 PSI will not pop the o-rings.

 

[01PSD]

Between 45 and 65 is good I think. Set my bro's at 58

 

[MorganY]

100+ pops o rings. Pressure drop depends on the truck and the condition of the stock pump. Set it at 65psi .+/- a few psi is fine.

 

[svilla]

No less than 45psi. I currently have mine set at 53psi measured after the heads, drops to 52 psi on full throttle runs.

There is a guy over on the .org that was doing some dyno tuning recently. He actually picked up around 200 ft lbs of torque dropping his fuel pressure down to I think 52 psi.

There were also a couple other guys reporting similar results running lowered pressure. Does anyone here have first hand experience with this?

 

[ODAWG714]

i gained 128 ft pounds of tq from dropping my pressure from 62 to 55. i didnt try anything lower than 55.

 

[range91]

Can anyone elaborate on why you would gain power with lower psi? The injector is doing the the pressure multiplication you would think with higher pressure it would just refill faster. Very interesting results

 

[2wd-fire]

mine runs at 75 all day no problems. i have been meaning to swap out the blue spring tho now that i have better fuel system

 

[FallenAuthority]

i gained 128 ft pounds of tq from dropping my pressure from 62 to 55. i didnt try anything lower than 55.

Really? I am intrigued to see how many more people had similar results

 

[2wd-fire]

Really? I am intrigued to see how many more people had similar results

this is the second time ive heard this. i remember reading about quick tricks doing 1/4 mile passes and it was consistently faster at 50~ psi than 70~ i have no idea why?

 

[machinestheman]

I must speculate that the injector can only fill so fast so with that being said anything less than this undetermined psi would leave the injector starved. so with any more pressure would generally serve no purpose so when running at a higher pressure your fuel pump must work harder to accomplish the higher pressures which would create more heat in the fuel.

so my educated guess is that it is due to less friction and less heat in the fuel I would be interested if anyone can provide any fuel temp input with the differences

 

[FX4 F2-Fifty]

http://youtu.be/o-1xNT8y9oI?t=5s

dont be scared:biggun:

 

[range91]

I must speculate that the injector can only fill so fast so with that being said anything less than this undetermined psi would leave the injector starved. so with any more pressure would generally serve no purpose so when running at a higher pressure your fuel pump must work harder to accomplish the higher pressures which would create more heat in the fuel.

so my educated guess is that it is due to less friction and less heat in the fuel I would be interested if anyone can provide any fuel temp input with the differences

The pump works at 100% duty cycle all the time and what ever fuel isnt used is just sent back to the tank fuel pump never works harder or easier with demand.

 

[FX4 F2-Fifty]

The pump works at 100% duty cycle all the time and what ever fuel isnt used is just sent back to the tank fuel pump never works harder or easier with demand.

Yes and no. The pump is always pumping 100%, but as you raise demand and/or pressure, the pump will work harder.

The pump is working a LOT harder at 100psi than 5psi, and much less volume at 100psi as well.

 

[HeavyAssault]

Yes and no. The pump is always pumping 100%, but as you raise demand and/or pressure, the pump will work harder.

The pump is working a LOT harder at 100psi than 5psi, and much less volume at 100psi as well.

So the PCM commands the fuel pump to increase pressure to meet the demand??

 

[range91]

Yes i agree with you on pressure and volume being relative to each other but on a rgulated return everything is full the regulator is the last thing before the tank. This shouldnt matter if its 45 or 85 psi the volume is limited to size of the line at that point. If you are reading from a factory setup where they regulate it before the heads then i can see volume and psi being different factors. correct me if i"m wrong