fuel pressure

[mirkoelek]

what i should set my fuel pressure to.????

i have evoIII 18psi of boost 650cc, 255hp, afcII

 

[oldman]

Around 44 psi without vacuum for 2g.

 

[mirkoelek]

Around 44 psi without vacuum for 2g.

why without vacuum
'

 

[oldman]

why without vacuum
'

To set base setting first remove the vacuum hose and plug up the nipple, re-attach the hose after you set it to 44psi. You can also use the fuel pump check valve to set the pressure without turning the car on like shown later in this article. http://www.vfaq.com/mods/FPR.html

 

[steve]

why without vacuum?

Because the fuel pressure regulator adjusts the pressure to track the intake manifold pressure to keep the injectors spraying the same amount of fuel per millisecond regradless of the vacuum or boost pressure.
Otherwise as the boost rises the injectors would spray less fuel and with enough boost not spray anything. That would be bad

Steve

 

[mirkoelek]

Because the fuel pressure regulator adjusts the pressure to track the intake manifold pressure to keep the injectors spraying the same amount of fuel per millisecond regradless of the vacuum or boost pressure.
Otherwise as the boost rises the injectors would spray less fuel and with enough boost not spray anything. That would be bad

Steve

thank you guys, ok now what do you know about dsmlinks, but your personal opinion

 

[steve]

what do you know about dsmlinks

If you can afford it get one!

Steve

 

[mirkoelek]

If you can afford it get one!

Steve

thats it, ! you are bored to tell me something more about it

 

[gsx rated98]

what happens if you are running to much fuel pressure? Like a few lbs higher then u should be?

 

[mirkoelek]

what happens if you are running to much fuel pressure? Like a few lbs higher then u should be?

good question

 

[steve]

thats it, ! you are bored to tell me something more about it

Everything you could want to know is on their web site http://www.dsmlink.com/.
Read that and if you have questions we can try to answer them. But it's hard to go wrong with the DSMlink unless you try buying one used.

Steve

 

[mirkoelek]

what happens if you are running to much fuel pressure? Like a few lbs higher then u should be?

you got good 1/4mile time on 95 mph, i had 104 and i was about 13.6sec

 

[mirkoelek]

Everything you could want to know is on their web site http://www.dsmlink.com/.
Read that and if you have questions we can try to answer them. But it's hard to go wrong with the DSMlink unless you try buying one used.

Steve

i said personal opinion , thanks anyway

 

[steve]

what happens if you are running to much fuel pressure? Like a few lbs higher then u should be?

The injectors put out a small amount more fuel that the ECU is expecting. A few pounds difference is well within the ability of the ECU to correct while in closed loop and might make you run slightly richer than normal in open loop.

Steve

 

[mirkoelek]

The injectors put out a small amount more fuel that the ECU is expecting. A few pounds difference is well within the ability of the ECU to correct while in closed loop and might make you run slightly richer than normal in open loop.

Steve

what is open and what is closed loop ????

 

[steve]

i said personal opinion , thanks anyway

I gave you my personal opinion. I give it again. If you can afford it get one.
It does what it's intended to do and there isn't anything better.

Open loop is when the ECU runs without feedback fron the O2 sensor like during WOT and closed loop is when the O2 sensor feedback is used to adjust the fuel trims to keep the Air Fuel mixture at 14.7:1 like at idle and when your cruising. If you had a AF blinkly light it cycles back and forth when the ECU is running closed loop.

Steve

 

[mirkoelek]

I gave you my personal opinion. I give it again. If you can afford it get one.
It does what it's intended to do and there isn't anything better.

Open loop is when the ECU runs without feedback fron the O2 sensor like during WOT and closed loop is when the O2 sensor feedback is used to adjust the fuel trims to keep the Air Fuel mixture at 14.7:1 like at idle and when your cruising. If you had a AF blinkly light it cycles back and forth when the ECU is running closed loop.

Steve

probably with dsmlinks i'm not gonna need to go to dyno-tuning....
if not how accurate you can tune up your car with dsmlinks
thanks