pantera_efi

iTrader: (1)

The method of supply fuel drive to the GDI Valve Cover pump IS a four lobe design.
The Spill Valve is TIMED to lobe position to control rail pressure.

When CompCams created their FIVE lobe camshaft pump drive, the E-92 EMS would need recalibration which there is NO object.

My question is if anyone has ever installed such a camshaft ?

Am I correct about my observation ?

Lance

musthaveLSx

What is the specific application?
If you are referring to GM, I can assist.

96 Comp T/A

iTrader: (8)

I am interested in the answer to this, if only to learn something more about direct injection? Why would GM need to time lobe pulses if they are electronically triggering the injectors in the head? I don't think it's like an old diesel where you have to time the pump, but I could be wrong.

musthaveLSx

There is no such timing.
The GM pump has an internal PRV, and an electronically controlled spill valve. The ECU controls the supply pressure based on the cal tables.

pantera_efi

iTrader: (1)

OK, lets say I agree only because I lack better knowledge.
The pump's internal Pressure Relief Valve, Spill Valve Control with System Pressure Sensor in closed loop control of Rail Pressure would all make sense.

What I was told is that a "pre-set" Spill Valve Control ramp setting was needed to "smooth" the rail pressure pulses caused from the four lobe pump drive.
The position of the pump lobes is provided by the CAS to the ECU for use as a modifier to the cal tables, a way to "pre-position" the Spill Valve.

My purpose is only to know if this requirement exists.

This requirement could become a control object in my GDI ECU which is in development.

This control object may enhance the fuel pressure regulation when "dual pumps" are fitted.

Lance

musthaveLSx

Apparently from discussing this with a calibrator, you are correct.
The demand system controls volume and rail pressure with the spill valve.
ECU must know the lobe position to allow actuation of spill valve only during positive output of the pump.
The control is pw/rr similar to a fuel injector.
I would assume the cal information for this would be very hard to obtain, as it is proprietary.
The LT4 is a 3 lobe design.
Spill valve is a normally open valve.

pantera_efi

iTrader: (1)

First, thank you, I read your qualified report in 2015.

My next question, for those here, is an opinion on the REMOVAL of the UEGO sensor requirement from my new ECU ?

The Ion Sensing Patent has expired.

Thus a simple ability to have eight "In Cylinder" AFR sensors.

Would that be acceptable ?
What other problems would I create ?

Lance