Cold Weather Observations

[NoVaGT]

Could be cam phasers.

It's the DI.

You've listened to your own motor, right?

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[engineermike]

You've listened to your own motor, right?

Yes of course, and gone much further. I’ve upgraded to the XDI HPFP45 and played quite a bit with GDI blend. Honestly, I’ve turned them off and on up to 90% blend and can’t hear a difference. I use vcmscanner, not the sound, to determine the GDI blend, rail pressure, and HPFP duty cycle.

The gen3 did go back to the old oil-pressure actuated phasers for 2 of the 4, which could be affected by cold oil viscosity.

 

[NoVaGT]

Yes of course, and gone much further. I’ve upgraded to the XDI HPFP45 and played quite a bit with GDI blend. Honestly, I’ve turned them off and on up to 90% blend and can’t hear a difference. I use vcmscanner, not the sound, to determine the GDI blend, rail pressure, and HPFP duty cycle.

The gen3 did go back to the old oil-pressure actuated phasers for 2 of the 4, which could be affected by cold oil viscosity.

How were the GENII cam phasers actuated? Electronically?

 

[engineermike]

Gen 2 was cam-torque actuated. Gen 3 kept cam-torque actuated on the intake cams but switched back to oil-actuated for exhaust. Ford claims better control while others say it’s due to the increased load from the HPFP. Maybe it’s both....better control needed due to extra load from the fuel pump?

 

[GregP27]

What the heck are PFI and DI?

 

[Sivi70980]

What the heck are PFI and DI?

Port Fuel Injected and Direct Injected. Our cars source their fuel both ways, it's awesome. Port injected fuel washed over the valves to keep them cleaner while Direct injected fuel performs better but I'm unsure exactly why. Waiting for someone else more knowledgeable to chime in now.

 

[engineermike]

..Port injected fuel washed over the valves to keep them cleaner while Direct injected fuel performs better but I'm unsure exactly why. Waiting for someone else more knowledgeable to chime in now.

It’s about reducing charge temperature to reduce knock. PFI sprays fuel on the back of the intake valve and the port walls. Most of the cooling from vaporization cools the metals surfaces rather than the air. GDI sprays into the cylinder with 1-3000 psi behind it, more finely atomizing, thus cooling the air charge and reducing knock. This is why the gen3 can run 12/1 compression on 87 octane. GDI has the disadvantage of particulate emissions, valve coking, and even oil contamination. Ford’s GDI system only uses GDI when it’s advantageous. For instance, at engine loads under 50% with a warm engine, it operates only on PFI since the knock resistance is not needed at that time.

I’ve played quite a bit with injection blend, pressures, and timing angles on my supercharged gen3.

 

[WildHorse]

Yesterday here was -6c, -3008 ft DA, I think the conversion was damn near 500 hp. Maybe just a tad over. Wonder if I can get the M/T street R bias plies to hook haha.

 

[Zooks527]

What the heck are PFI and DI?

Port Injection (where the fuel is injected before the intake valves) and Direct Injection (where the fuel is injected directly into the cylinder).

 

[NoVaGT]

What the heck are PFI and DI?

Port Fuel Injection and Direct Injection. 2018+ GEN3 Coyotes have both, and cycle back and forth between them, and sometimes use both at the same time.

32 degrees this morning. Start car, get out and light cigarette.

CLACK-CLACK-CLACK-CLACK (for a minute or so) of straight DI, then it switched to PFI for awhile and just hummed like a sewing machine, almost silent. Then a little of both.

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