Today i decided to start from a stock Lt1 file to try to tune my car.
No more copying and editing someone elses tables.

How do i go about adjusting the 400-4000 rpm spark advance tables?
As detailed as possible
Thanks

 

Using a dyno?

I have read that you want to adjust the timing so that you get to a certain MAP reading or as close as possible.

So I guess you make a change, log it, change, log, etc... until you get it where you want.

That's where a dyno would help. You could just start it up and drive it on the dyno without having to worry about watching the road.

I think you tune for cruising at each of the boundries or something, watching the MAP reading and knock retard.

 

Saint, here's how I see it, I'm sure others have different ideas. You need to recognize that there are two separate factors in that table, rpm and kpa (vacuum). I've read the best spark curve begins just off idle, that way fluctuating idle rpm and idle vacuum don't cause idle timing to fluctuate. So find out what values are at idle and match them up at your closed tps advance table at idle speed. Then look at your "mechanical" advance which will be in the 90-100 kpa range. This is for WOT and should reach its maximum by around 2500-2800 rpm. Just how much advance and how soon is going to be trial and error on the dyno.
"Vacuum advance" is added below the 90 kpa range and is added gradually as vacuum increases (lower kpa). This will help fuel economy and possibly cooler engine temps. I remember the stock tables end up reducing some vacuum advance at very low kpa values and I can only guess that would be for engine braking.
Hope that helps.