Ignition Timing Table Interpolation woes

[foxdie]

Hi all,

This ones got me baffled, spent a couple of hours researching into this but can't seem to find out why this is happening, in short, my 7202 is interpolating between the high / low ignition octane maps with no knock and 100% octane level, leaning towards the low octane table.

I'm running KSMods v1.03, currently with stock ignition tables (well, Kens larger tables loaded with as close to a stock 7202 rom's timing as he could make it), here's an example EvoScan log (save to disk, rename to .csv) - http://db.tt/PcKPauHg - although I didn't log intake temp, there shouldn't have been much heat soak.

Another example, on one power run after the car had been moving non-stop for a good 60~ seconds beforehand, I logged a timing advance of 14 degrees with no knock and 100% octane at 140 load / 4700 RPM, the low octane table value for that load / RPM is 8 degrees, the high octane is 21 degrees :dizzy2:

Anyone able to shed any insight?

[Anderz]

Hmm that indees looks like it's interpolating although octanerating is 100. Are both ignition maps equal? Just wondering if it has something to do with what is described in post 123 in this thread?
http://www.clubvr4.com/forum/showthread.php?58517-Kenneth-s-ECU-Mods-%281.02-IMPORTANT-UPDATE%29/page7

[foxdie]

Are both ignition maps equal?

Both High Octane Ignition tables are identical and both Low Octane Ignition tables are identical.

The first image shows the point on the graph I've used for reference, the second shows all the table values that it could possibly be interpolating between (with the actual table entries selected that the marker in the first image is using)...

You can see the actual timing advance is much closer to the Low Octane table than the high, despite the lack of Knock and 100% Octane Rating.

48830
48829

Ps. During my runs, the air con was turned off (as I didn't want it sapping engine power).

[foxdie]

Herpa derp!

This turned out to be a red herring, phew :)

Anderz / Lateshow, the load calc formula of 0.2326*x is wrong, it should definitely be 0.3125*x (Ken himself confirmed it), here's a graph comparing all the ECU load values for a 3rd gear pull :)

49072

[Kenneth]

And the timing?

[foxdie]

And the timing?

Is exactly as it should be, now I know its working perfectly I'm going to try advancing it a couple of degrees :)

[lateshow]

Has Kenneth changed this as the OEM rom definetely uses 0,2326 instead of 0,3125?

Foxdie: What do you have in the MUT table under MUT 00 and 01 ?

[foxdie]

The values I have in MUT 00 and MUT 01 table are: F041 F040

[Nick Mann]

Jason advancing timing can increase knock a fair bit. Watch carefully as you do it!

[foxdie]

Jason advancing timing can increase knock a fair bit. Watch carefully as you do it!

Yep I'm aware, my plan is thus;

1. Get boost stable at 1.0 bar
2. Gradually increase timing, 2 degrees at a time until it starts to knock
3. Take 2 degrees off and maybe add a little more fuelling to make it stable
4. Test thoroughly to try and induce knock, if I am able to, repeat step 3

[Kenneth]

That doesn't look right... I think I use F0CE/F



The values I have in MUT 00 and MUT 01 table are: F041 F040