Injector End Angle Tuning

[Gunnytron]

Cool, thanks zwede.

[zwede]

Dumb question, but is the Fuel Pressure Delta where you enter the Actual System Fuel Pressure? E.G. My LS1 runs at 60 psi. Awesome spreadsheet BTW.

Yes, you'd enter 60 psi in your case. Technically, it's the difference between fuel rail pressure and intake runner pressure.

[Paul P]

Danny is the expert, I'd follow his advice. Just for the record, I didn't use any Excel spreadsheet for the Injector End Angle setup either.

[Gunnytron]

I mean on line 16 of the Injector End Angle Excel spreadsheet.

[Danny Cabral]

http://forums.holley.com/showthread....ents-Read-This (Initial Checks & Adjustments - Read Step # 2)

[Gunnytron]

Dumb question, but is the Fuel Pressure Delta where you enter the Actual System Fuel Pressure? E.G. My LS1 runs at 60 psi. Awesome spreadsheet BTW.

[zwede]

It lets you change part of the map without affecting other parts. Example: You're happy with high load & RPM, but feel you want to inject earlier at idle and low load. You can change the lower slope value to do this.

If you change the values you'll see how (where) it changes the map. There's usually no reason to change from the default values.

[98SN95]

I'm confused by the terms "Upper Slope Offset" and "Lower Slope Offset". Could anyone explain this please?

[allan5oh]

It'd use whatever value is in <Engine Parameters> <Fuel Injection Information> <Injector End Angle>.
Sometimes it's 0°, sometimes it's -90°.

[masheim]

I’ve read this entire IEA thread and another on YB (still learning) from some of the same and have this question. If entering the cam values and injector placement, but NOT Enabling the IEA Table in GCF V5, does HP use its own calculation for the IEA values? If yes, are these the same values that display if you Enabled the IEA Table and did a Recalculate?

[allan5oh]

Then you'd have a puddle of fuel sitting on the intake valve when it opens during overlap, and much of the fuel will be pushed into other cylinders.

Exactly. Intake valve closing would be around 50-90° according to the Holley numbers. From the factory Holley comes with a 0° setting, which is BDC of the intake stroke. This is just about the worst time to spray I find, and the people that have this setting seem to benefit the most from IEA tuning. However, with a factory small cam, there may be benefits to spraying much earlier well before the intake valve opens. This is because those cams have little overlap.

[zwede]

Then you'd have a puddle of fuel sitting on the intake valve when it opens during overlap, and much of the fuel will be pushed into other cylinders.

[Robs455]

Thanks Allan, I got you. What about to spray the the fuel as soon as possible? I mean to spray it shorty after the intake valve is closed, let's say around -450° or even more degrees. Has anyone ever tried this?

[allan5oh]

That's the upper slope. At that point the "ideal injection window" is full and we're now advancing the beginning of injection to fit the larger PW. The lower slope (the other numbers) is where we retard the end of injection as PW goes up, but we can fit it within the window.

[Robs455]

Hi Aaron. Why did you stop the IEA in the table?