maybe the ACD tells the ECU when the wheels are loosing traction and it does something to the power?

 

this whole thing right know makes me think about those 3 different tables for the MIVEC engines. Maybe this has to do something with it???

 

no - mrfred AND myself have pretty much verified that the 3 ignition tables are todo with MIVEC rather than ACD.

 

Any further data reports? It makes sense the ECU can pull timing to help wheel spin.

 

I haven't had a single bogged launch episode since then... for what it's worth (not much)

 

The fact that there is a wire going from ACD controller to ECU leads me to believe there is interaction between the two controllers. Exactly what I have no clue

 

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Here is a link to a great document that does indeed say the ACD adjusts based on throttle position. This means the ACD/AYC controller does indeed work off of input from ECU (pg. 13 in doc. or pg.14 from Acrobat)

http://www.myevo.com/Lancer%20evo%20VIII.pdf

 

Yeah it's a TPS signal - its not coming from the ECU, but rather gets split from the TPS to the ECU and AYC controller...

By all means do your own investigation as I may(read probably) have missed something.

 

I just looked in the Evo9 supplement service manual and there are two wires on ACD ecu pins 36 and 39 and two wires on ECU pins 78 and 79 I can see where the wire connects for tps on pin 78 (c51) ECU to pin 36 on ACD controller for TPS. The other connection pin 39 on ACD shows directional flow arrow to ECU from ACD if I read Schematic correctly. I was on pages 3-30,3-33 and ACD part which shows the best is on 3-133.



I guess someone with energy could monitor voltage (if any) on that other line (let alone the tps line). I assume the TPS signal would be in the standard A to D range of 0-5 volts but I do not profess to be an expert

 

I would assume its the associated ground reference... Not sure why they wouldn't connect directly to the TPS for the Ground like they did for signal??

 

From the symbol ~ associated to 79 (C-51) it seems to be an analog signal, similar to 78 where the analog signal from TPS enter in a divider (there are 2 resistors in the scheme).

 

I have seen no mapping references anywhere that would cause the ECU to use a different timing curve based on ACD settings. There would need to be a full 3D table with either a trim or a full replacement timing table to do anything of this magnitude and there arent anymore large 3D tables left to be found in most of the roms. Economy may slightly be effected if there is more drag between the diffs but that would be about it.

I would tend to think its more a placebo effect unless more solid data or code is found.

 

not necessarily, if the AYC/ACD is telling the ECU to reduce torque (like the X can) then it wouldn't need a 3d map... It might just be a very basic subtraction of timing.

 

It would be apparent under all conditions then. You should be able to drive along cruising at constant rpm, load, and timing, and when you change the ACD mode see a direct change in timing. Otherwise it would need certain conditions to be met which would bring with it 2D maps to judge the degree of retard. Do you pull 1 degree, 2,3,4,5, 20 degrees? Do you do it suddenly or do it depending on the amount of slip? How much torque is being reduced with just 1 degree? How does it know if I am on ice spikes or not and maybe I do have traction but want the snow mode? So many variables and no reason why Mitsu would do it.

Pulling timing under wheel-spin would also mean it runs a form of traction control. Something that is not really documented anywhere I have seen for the 7,8 or 9.

Trying not to be a party pooper but for now I will wait for the hard data before jumping up and down with celebration.