Timing???

[Russ K]

These are the main spark table values. If the IAT temp gets to 98*F, then the timing is reduced. So if the air temp is below 98*F, then the scanner shows the same timing as the main spark tables at operating temp (~172*F)

Russ Kemp

[Main_One]

You don't get extra advance from PE, or have you zero'ed it out?

[Russ K]

The PE spark table is 0 stock. On all vehicles that have PE spark, I zero out the table and set up the main spark tables. The PE spark table is mainly used for trucks that have a PE delay, so no PE, then no extra spark because the AFR will be lean. The 6L and 8.1L trucks never enter PE that I've seen.

Russ Kemp

[chrisj6]

I have all the delay values zeroed out on my 5.3L truck and the enrichment rate set to the max, and I still have a delay. PE doesnt kick in until about 3600. So I still use that AFR adder.

[Russ K]

Send me you file, as I've also tuned two 1999 5.3 trucks and had no PE delay after tuning. The AFR spark table adds timing not fuel.

Russ Kemp

[chrisj6]

Oh yeah I know it adds spark, but I just use it so I only get that extra spark when PE kicks in.

[Russ K]

You want the PE delay rpm to be 0 . Stock is 3200 rpm. Then the truck will enter PE as soon as the PE enable TPS threshold vs rpm is met.

Russ Kemp

[Main_One]

So Russ, do you think the trucks' 5.3 timing should match your Z06's?

[Russ K]

So Russ, do you think the trucks' 5.3 timing should match your Z06's?

Depends on the camshaft & CR. With my 234/228 cam, there is more low rpm timing, and the timing curve is steeper than a stock cam. Wot total timing is 23* @ .72 g/cyl above 4400 rpm.

Russ Kemp

[chrisj6]

Ever delay possible on my truck is 0, and I still have it. I think its just something in the truck OS.

Stock PE delay in the trucks is 5500.