TINKRD

iTrader: (27)

fuel pressure. you can turn your base fuel pressure up to compensate for a high duty cycle. With a base fuel pressure of 55ish psi my injectors are already at 85% duty cycle with just 9lbs. so say turn the base fuel pressure up to 70psi and peak boost is 20lbs. now we're looking at 90psi. which is well within the capabilities of the fuel pump (fuel pump can support 120psi). what are the pros/cons of doing this?

RAACCR

Your fuel pump flow will decrease as pressure rises. You need to verify that your pump can support the required flow @ 90 psi on the voltage you're feeding it.

TINKRD

iTrader: (27)

so let's throw that into the equation. say the voltage stays the same to sustain the 90psi.

now are there any con's?

Ryan K

iTrader: (11)

There is a point where the injectors start to fail to open when commanded. I believe that this can start at around 80psi (differential pressure across the injector) some injectors are good to about 100psi d/p.

So, the limiting factors are:
-fuel pump capacity at the higher pressures
-the injector's ability to operate at larger d/p's

Most electric fuel pump's capacity drops significantly as pressure rises:


And here is a video test of Fuel injectors at higher pressures:
http://youtu.be/7oTirEZNRw8

Lonnies Performance

iTrader: (16)

Also keep in mind that the fuel pressure is not linear to the pressure increase, but inreases with the square root of the increase. This means double the pressure is only a 50% flow increase.

Going form 43.5 to 58psi is a 15% flow increase but a 33% pressure increase.

Going from 55 to 70psi is only a 12% flow increase. Not sure if this is enough to help you out.

deatschwerks

iTrader: (2)

Also, higher pressures can affect your injector latency values as the pintle is having to overcome a higher pressure (read: slower reaction) to open.

It is not a major change, but enough that it could affect your lower pulse width operation.