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Old Sun, September 19th, 2010, 05:23 PM
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Quote:
Originally Posted by 907dave View Post
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.
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