Modified IDM and tuning

[cleatus12r]

You can run it all day like that on a stock pump too. But really, there's no need; maybe HPOP may not be able to keep up....or because Ford wanted to do it for other reasons.

The desired ICP map is based on mass fuel desired and RPM.

Here's an exercise for you (do this in your head while looking at the map).

From an idle, punch the accelerator pedal.
MFD is above 70
RPM starts at <700

Where is ICP?

What do we know about the relationship of ICP and injector pulse width for a given MFD?
(Hint: check the pulse width map)


Now, using the ICP map, pulse width map, and any given MFD, you can figure out what is happening when you replace that drop with a straight line.

Bonus points for showing work......

[cleatus12r]

Oh, and bean dip is THE BOMB.....

Both when you eat it and also a few hours later!

[Shaw]

Well it depends on what bin I look at. If its one that Bill wrote, it would hold the PW thru the dip, if its the stock bin then you would drop PW for a short period thru the dip. Am I seeing this correctly?

(Ill pass on the bonus points for now)

[907DAVE]

Originally Posted by cleatus12r

Here's an exercise for you (do this in your head while looking at the map).

From an idle, punch the accelerator pedal.
MFD is above 70
RPM starts at <700

Where is ICP?

3045 ICP

What do we know about the relationship of ICP and injector pulse width for a given MFD?

As ICP increases - PW decreases

Now, using the ICP map, pulse width map, and any given MFD, you can figure out what is happening when you replace that drop with a straight line.

PW never increases, instead just stays steady.


Bonus points for showing work......

Here ya go.......



Pretty sure I missed something though, too early for all this thinking.

[cleatus12r]

No, it's that the bench you used is FAR too clean. Has someone been building automatic transmissions on that one lately?

That will work. This obviously is not factoring in the PW multiplier (which on a stock truck at operating temperature is 1 anyway).

Now, since we have a bit of information here, why would we go about increasing the injector on-time instead of maintaining higher ICP to get the same MFD?

[907DAVE]

Maybe........



Just a spare for the pickup.

Originally Posted by cleatus12r

Now, since we have a bit of information here, why would we go about increasing the injector on-time instead of maintaining higher ICP to get the same MFD?

Good question.

Maybe because the injector is too slow, even with the higher ICP.

[cleatus12r]

I would only be able to venture a guess to that one. Basically, you're accomplishing the same thing either way, but I assume that the lower ICP/higher PW is accomplishing the task of introducing a bit of heat to the turbocharger turbine........

OR

The power will come on a bit more slowly and with less aggressiveness with your foot to the wood.

Which reason? Heck, I don't know. It thought that you might have an idea.

[907DAVE]

So then - back to my original question, how to decrease spool time.

Looks like dropping ICP in the low RPM's, or pulling some timing out would both help this situation.

Would you venture to guess this is what Ford had in mind when designing these maps?

Seems like there would be a trade off, crispy clean throttle - or faster spool up.

[907DAVE]

And how the heck are you replying when you are offline?

[Pocket]

Originally Posted by 907dave

So then - back to my original question, how to decrease spool time.

Looks like dropping ICP in the low RPM's, or pulling some timing out would both help this situation.

Would you venture to guess this is what Ford had in mind when designing these maps?

Seems like there would be a trade off, crispy clean throttle - or faster spool up.

Try adding too much fuel at lower RPM's. What happens? You get lots of smoke, and a turbo that seems to take forever to light.

Adding more fuel at lower RPM's doesn't increase the spool up of the turbo. In fact, it can be quite the opposite, increasing lag time until the turbo finally catches up, then you get a neck snapping response after you've killed a few hundred polar bears with the exhaust trail left behind

In the mean time.... with all that fueling and no air, EGT's rise quickly. It's especially troubling if your driving up a hill and the engine loses speed. That's when you start seeing smoke pour out the tailpipe, and the EGT gauge rises quickly.

That's why I like my tuning to have pretty much bone stock fueling for the first half of the pedal.

Think of it in terms of pulsewidth... not so much ICP and timing (although those are important too). The main thing to look at is how much fuel is being called for right off idle, and in the RPM range before the turbo spools.