Ignition tables

[mrQQ]

Hi,

can someone please explain, I've read that Max table is not Max at all. If not, then which tables should I adjust to tune Ignition for performance?

[mrQQ]

also,

why is CL timing table much lower than OL/CL transition and OL tables? Isn't timing supposed to be higher in closed loop for mileage? My logs in CL show timing much closer to OL tables than to CL tables..

[mrQQ]

OL seems to follow OL Normal table. However, for closed looop operation it's all over the place, I can't figure out what does it match.

Anyway, is there any way to increase non-turbo operating range performance? like 1k-2.5k? are there any gains from increasing timing in this range?

[Steve @ VersaTune]

The timing starts at the normal table and, when operating conditions are stable, it slowly moves towards the max table. Under OL operation, it is rarely stable, so you see it follow the OL normal table closely. Under CL cruise, it will move towards the Max table.

[skiptownmcat]

I think I'm going to start fettling with the cl timing to try and get better economy.

[mrQQ]

why are CL tables lower than OL? why are some of the Max'es lower than Normals?

[skiptownmcat]

why are CL tables lower than OL? why are some of the Max'es lower than Normals?

I think its because when you go to ol you're accelerating quickly so advancing the timing more to "catch" the next sweet spot of the piston cycle. I'm probably a mile off, steve should be able to tell us.
As for the max values being lower than the base values, I have absolutely no idea.

Here's a question. if under steady state the timing goes from base to max, then should I just set the cl max values high and let the ecu do it's thing or increase the base values as well?

[mrQQ]

we need Steve on this

while we're waiting.. can you guys share your OL timing tables? with the loads you're reaching

[skiptownmcat]

What I did was look at the WOT loads then advance 3 cells on the vertical axis (covering the load you hit) by half a degree. I did that for each rpm point, keep going till you start to see knock in the logs that is repeatable in more than one log and in the same place (a sign of true KR). When that happens back it down half a degree and then don't touch that rpm point again and keep doing the others the same way. When they were as far as they could go I smoothed the figures back up the table.
When doing timing changes I actually let the car sit running for a while to induce some heatsoak, it gives you a worst case scenario. if it's not knocking under high bats, it's not going to knock at all.

[Steve @ VersaTune]

why are CL tables lower than OL? why are some of the Max'es lower than Normals?

In CL operation, you are more likely to be cruising at a steady state and move towards the "Max" timing table values. In OL operation, you are most typically accelerating and not operating at a steady state. So, in OL, you are less likely to move towards the "Max" table. The "Max" name is a bit of a misnomer since there are some places where the values are lower than the normal table. Very low load decel is a case where it has higher timing on the normal tables.