RomRaider

I have a 2004 sti. I know the equation for total timing and part of that equation is timing advance * IAM. I have 3 tables for timing advance, timing advance additive (maximum), timing advance primary 1 (maximum) and timing advance primary 2 (maximum). Which of these tables is used in the total timing equation and when are the other tables used. Thanks.

unique to the usdm 04-06 STi, the switch between primary 1/2 occurs based on knock and conditions conducive to knock. It actually ramps between the two tables when the switching occurs, using a portion of each (there are various logger parameters added so you can see what is happening (ex. map ratio)- see the logger description sticky). The additive advance follows the same idea, with the difference being that this additional advance can range from 0 to the max advance in the map (this is added to the primary 1/2 result). There's a lot going on to determine the map switching for primary 1/2 and the amount of additive advance, so it is not something I can just explain in a few sentences. Just as an example, a some of what is considered is IAT, RPM, the current additive advance map value, time since exiting CL, accelerator position (near WOT/WOT), FBKC, primary 1/2 advance, the difference between primary 1 and 2, manifold pressure, knock signal, etc.

Thanks merchgod that cleared up things quite a bit. I am still curious however, how other people are tuning their timing tables. Are people just making their primary 1/2 tables the same? This is confusing to me because people always talk about changing their timing advance table but i never hear anyone talking about 3 different tables. Thanks for your help merchgod.

Just depends on whether you want to keep the factory logic or not. It is unusal in that it is not present on any other models (not even non-USDM STis). You can log a variety of the unique parameters for these ECUs related to this logic to determine what each table is doing and get an idea. However, if you prefer more consistent timing, you can disable the additive logic by enabling the "alternate advance mode" switch or zero out the additive table entirely. And then you can make the primary 1/2 tables the same.

Using the 0.8.2b (10-05-08) definitions, viewing a stock 06 sti map.

In the 'Timing Advance Additive (Maximum)' table description, both an 'advance ratio multiplier' and 'additive multiplier' are described in the calculation. (I'm not trying to be picky and point out oversights, I am trying to be very cautious to make sure I am understanding the interaction of these variables correctly).

Are these intended to be the same value, or are these distinct scalars?

Similarly, is this the loggable value 'Map Ratio (Primary)'?
advance ratio multiplier == Map Ratio (Primary)?
additive multiplier == Map Ratio (Primary)?


Thanks!

read the extended parameter logger desc in the ecu and logger defs forum:

Map Ratio Primary Advance 1/2* [USDM 04-06 STis ONLY] (N/A,4) - This is the multiplier which determines the primary advance based on the 'Timing Advance Primary 1 (Maximum)' and 'Timing Advance Primary 2 (Maximum)' tables as follows (additive advance and the IAM are not reflected in this value):
Primary advance = (Timing Advance Primary 2 map value * Map Ratio Multiplier) + (Timing Advance Primary 1 map value * (1.0 - Map Ratio Multiplier))

Ignition Timing Advance Additive* [USDM 04-06 STis ONLY] - This is the current advance additive as determined by the 'Timing Advance Additive (Maximum)' table with the additive multiplier applied.

Ignition Timing Primary Advance 1/2* [USDM 04-06 STis ONLY] - This is the final primary advance based on the 'Timing Advance Primary 1 (Maximum)' and 'Timing Advance Primary 2 (Maximum)' tables (additive advance and the IAM are not reflected in this value).

*NOTE: This applies to USDM 04-06 STis ONLY.

While brushing up on my reading for some spring tuning (one thing I would like to do is switch my map to the timing *Alternate Advance Mode*).

It occurred to me...
-If the multiplier for 'Base Timing A/B' and 'Timing Advance Additive' are one and the same
-'Timing Advance Additive' is not subject to IAM scaling

Then...
-Adding values from 'Timing Advance Additive' to 'Base Timing B' (and zero'ing out 'Timing Advance Additive') would result in an identical tune.

This strikes me as extremely silly. Why create the 'Timing Advance Additive' table/logic. Am I missing something?

THE FOLLOWING ONLY APPLIES TO THE USDM 04-06 STI GENERALLY:
The base timing "map ratio" multiplier is not the same as the advance additive multiplier. I'm not sure of the distinction between the Base A/B tables. From what I can tell, only one of the tables is ever used on the USDM STi, although I am not absolutely certain enough to remove the unused table. Whatever it is, it has nothing to do with the knock history/conditions elements that decide timing advance primary 1/2 and additive advance.

The purpose of the timing advance primary and advance additive logic seems to be to enable to run more timing when knock conditions are low. This sounds like the same function of the IAM, however, the distinction is that the IAM dropping is due to an actual knock event, whereas the additive multiplier and primary 1/2 switching is based on knock events, history of knock (short period of time), conditions that might lead to knock (such as high IAT), and conditions where a knock event could be more damaging.

Thanks merchgod!

I think an update is need to the Extended parameter descriptions for RomRaider's logger thread...

yeah, that's wrong. I'll fix that after the next release - the names of these tables are changing anyway to make things more clear.