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View Full Version : Stock GM boosted cars? How is PE set?



N0DIH
May 5th, 2010, 03:07 PM
I am wondering how other GM cars that came stock boosted, how did GM do the Power Enrichment mode?

On my 3800 which is likely by far the most widely used SC engine from GM, and GM has 1 table for PE Mode Fuel AFR (not EQ grrrrr) and then another table, RPM vs Time in PE vs AFR adder. Which the the longer you are in PE, the richer it gets, ok fine for the first 8 seconds but by the time you are at 25 seconds on the loud pedal, you are looking at richer than 10:1 on gas.

So I am more than anything very curious how GM does it today on turbo or supercharged cars.

The few tunes I looked at seem to have a 2D table, rpm vs Lambda and that is it.

Do they still add more enrichment the longer you are on the loud pedal?

Thanks!

CalEditor
May 9th, 2010, 07:28 AM
I am wondering how other GM cars that came stock boosted, how did GM do the Power Enrichment mode?

On my 3800

the the longer you are in PE, the richer it gets, ok fine for the first 8 seconds but by the time you are at 25 seconds on the loud pedal, you are looking at richer than 10:1 on gas.
Thanks!

How about some type of protection? Piston Protection?
or


Power Enrich Fuel Adder vs. RPM vs. Time: This table adds to the base AFR in relation to RPM and time in PE mode. It is used to provide additional RPM and time based enrichment and is similar to the PE vs RPM table on V8 engines, but with an additional time component. Remember, this value adds to the Base PE AFR so positive numbers here are leaner and negative numbers are richer.