INJECTOR TESTING and FLOW by HorsepowerFreaks using ID 2000cc Injectors

[HPF Chris]

There's been some discussion about injectors on these forums so I asked John to take our new ID 2000 injectors along with some other injectors and give a tutorial on injector flow rates and spray patterns as various fuel pressures and engine rpms. At the end he will show you a lower quality injector literally shut off from too much fuel pressure.

http://www.youtube.com/watch?v=oK2LGTPw2ls

[milKt]

http://www.injectordynamics.com/ID2000.html

They are setting the standard all right.

[hsvturbo]

John stated the race car runs 60 psi fuel pressure and 30 psi of boost. With a one to one fuel reg, the fuel pressure raises to 90 psi (under boost), but your fuel flow calculations will still be at 60 psid, not 90 psid. Or did I miss something?

[gstuning]

John stated the race car runs 60 psi fuel pressure and 30 psi of boost. With a one to one fuel reg, the fuel pressure raises to 90 psi (under boost), but your fuel flow calculations will still be at 60 psid, not 90 psid. Or did I miss something?

That is correct.

It´s the differential pressure across the injectors that determines the flow rate for a given pulsewidth.

[5mall5nail5]

Yeah the PSI flow out of the nozzle will be reflecting the ambient pressure (1 atm + 2 bar) vs 90= 60, not 90 psi

You can think of it as needing excess pressure over ambient pressure in the manifold to fight the pressure back-flowing into the fuel rail.

AKA your fuel consumption is off based on your calculations.

[DUDMD]

John stated the race car runs 60 psi fuel pressure and 30 psi of boost. With a one to one fuel reg, the fuel pressure raises to 90 psi (under boost), but your fuel flow calculations will still be at 60 psid, not 90 psid. Or did I miss something?

That's what I was thinking, wouldn't the boost pressure in the intake manifold be acting against fuel coming out of the injector? Thus needing the FPR to bring up the pressure in order to keep the injector flowing the same.

[5mall5nail5]

That's what I was thinking, wouldn't the boost pressure in the intake manifold be acting against fuel coming out of the injector? Thus needing the FPR to bring up the pressure in order to keep the injector flowing the same.

Yup - to inject a true 90 psi into the manifold the car would have to be running 30 psi and have a base pressure of 90 psi. Then the system would run 120 rail pressure, but net 90 psi with 30 psi of environmental pressure.