Quick timing table adjustment question
 

I have an RTEK 2.0 in my S4 NA. I just want to verify that my understanding of how the timing adjustmet works is correct.

If I were to adjust only a leading timing value by 3 degrees advanced for example, my understanding is that the split stays the same.

If so then that means when I adjust that leading value by 3 degrees advanced, then the trailing value would be advanced by 3 degrees as well, maintaining the value from the split table.

Is this correct?

Yes, the leading and trailing values will always be spaced apart by the values in the split table.

Nope. When you adjust the leading timing you need to adjust the split table in order for it to stay correct. The split table is created in software by the palm. Trust me on this. I put in part of the leading table then all the split then went back to the leading to finish and had to end up adjusting the split all over again.

This is not correct. It's actually opposite. The split will always show what the difference is between the leading and trailing.

If you adjust the split (which isn't actually a table in the ECU), the leading stays the same and the trailing is actually adjusted. This is explained in detail in the manual.

Turbo2ltr, the question wasn't about adjusting the split table. It was about adjusting the leading table alone, and what affect that would have. The manual does not cover that.

And actually what I said is true (split = difference/spacing between leading and trailing), but I was assuming changes to the leading map would alter the trailing map according to the split. So instead changes to the leading map will lead to changes to the split values w/ the trailing map staying unchanged?

Currently I have only made small changes to my leading map (in LOAD based mode), so for cells I retarded the leading timing, I should see a decreased split due to the trailing timing staying fixed?

Example:
Leading is 15*, Trailing is 0* & therefore split is 15*.

1) If I retard the leading to 14*, without touching the other maps, trailing will still be 0* & split will be 14*?

OR

2) If I retard the leading to 14*, without touching the other maps, trailing will change to -1* & split will remain 15*?

So which is it? From Solareon's description is sounds like #1 is true. I'll have to break out my palm and make some adjustments later today.

This is correct.

Technically there are only two maps you can adjust, leading and trailing. At no time can you adjust one of these maps and have something in the other map change as they are two seperate maps. The split map is a "realtime" map that is calculated from the leading and trailing. If you change the leading or trailing, the split must change or they wouldn't add up.

The only "exception" is if you change the split. It's like changing the 4 to a 5 in the equation 2+2=4 . In order for it to be true, something has to change on the other side of the equals sign. So It is hard coded that if you change the split, the trailing is adjusted so the equation remains valid.

yes, 1 is true.

Case in point; I advanced my lead and parts of the split went negative. My trailing stayed the same.

Thanks for clearing this up. It seems my initial assumption was wrong, and I will need to go in and adjust my trailing timing values as well.

slight ressurection
 

So am I correct in assuming that the Rtek can do negative split correctly?

I'm looking in to one for an S4 NA.

Thanks

There's nothing to "do" correctly. Split is the difference between the leading and trailing. Thats it. See post 6 on how the rtek handles changes to the split table.

I guess my question should be-if I set the trailing before the leading to get a negative split, will the Rtek interpret it correctly? My guess is yes.

The rtek doesnt care what the split is... the split doesn't exist except as a virtual table in the software for display purposes. There's only leading and trailing and the ECU will follow whatever you set those two maps to as those are the only two actual maps in the ECU. If the values programmed happen to create what we call a negative split, it could care less.

Awesome, thanks. :)

I should have my S4 NA RTEK 2.0 with Palm for sale in the next couple months. Going to a v8, and obviously won't need the RTEK for that :)

Am I actually glad that someone is swapping to a V8? What a strange feeling... ;)