Thread: What makes an Economy tune?
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Old Fri, December 25th, 2009, 10:37 PM
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The reason the map is so complicated isn't because of the time value in the table but the fact that time is fixed and engine speed varies. That means that the actual SOI degree variance increases as the RPMs increase.

For example:

At 1500 RPM, the crankshaft will rotate 9 degrees per millisecond.
At 2600 RPM, the crankshaft will rotate 15.6 degrees per millisecond.

Using the same RPM values and a similar delay value will give you a difference in overall SOI advance difference of 6.6 degrees at 1ms and it goes up with more delay as long as all the other SOI adders and maps stay the same. For example, if the delay is doubled to 2ms, the actual SOI advance doubles as well to 13.2 degrees.

I hope this makes sense....
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Tuning, PCM flashing, and burning chips for 7.3s since 2008. Repairing all aspects of 7.3L Powerstrokes for 25 years.
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Last edited by cleatus12r; Fri, December 25th, 2009 at 10:50 PM.
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