Evo 9 ACD ECU Tuning?

[k4nnon]

Hey all this is kind of unrelated to Link or engine tuning, but does anyone on here have any experience with tuning or reflashing the evo 9 ACD ecu? I have a USDM evo 9 and im setting up for some autocross this year. I do all of my own tuning but i have never touched the acd unit. I have done plenty of reading on it and have some maps from other people who have done this but i just wantedto check here and see if anyone has any useful info or maps they would like to share. Thanks!!

[mapper]

I have done the stock ACD ECU and worked out a stragey on G4X to control Center differentials with 3 different maps for acceleration, and 3 maps for braking. Additionally, there is a slip and steering angle overlay. 
Works quite good! 

[k4nnon]

On 3/16/2023 at 6:02 PM, mapper said:

Hey thanks for the input. This is very interesting,, I wasn’t even thinking of trying to set up any type of ACD control with the G4x. I didn’t think it was possible because the ACD ecu is its own separate unit. Can I ask how you accomplished this and how it compares to working against a well tuned ACD ecu. I’m guessing you added the acd control wires as inputs to the g4x and then created mapping and set up? I’m interested so please share more if you are willing. And thanks again! 

[Iguanapeluda]

On 3/16/2023 at 11:02 PM, mapper said:

I have done the stock ACD ECU and worked out a stragey on G4X to control Center differentials with 3 different maps for acceleration, and 3 maps for braking. Additionally, there is a slip and steering angle overlay. 
Works quite good! 

Interesting....waiting a explanation..please.

[mapper]

On 3/19/2023 at 9:45 PM, Iguanapeluda said:

Interesting....waiting a explanation..please.

Just use Virtual Aux, several GP PWM Tables and math to combine anything. 

[ROB-80E]

IMO nothing can compare to what the stock ECU is capable of doing.  Not MDC, Emtron, link or anything else that doesn't use the same level of inputs and calculations.

The MAJOR drawback with the factory ECU is the ability to log (easily).  It can be done using EvoScan, but it can't be done internally.   This is the major bonus of the Motec or Emtron (or possibly even Link...i haven't had any experience here) is that you can accurately log the Center Diff control parameters just as easy as everything else in the engine ECU.

Now don't get me wrong, you can certainly achieve great results with an aftermarket ACD solution, and the ability to find someone to tune them is probably easier too....but yeah I've been doing the factory ecu setup for over 10 years now and see no reason to change.

The attachment is a simplified control diagram of the factory ECU.

[mapper]

On 11/2/2023 at 11:08 AM, ROB-80E said:

IMO nothing can compare to what the stock ECU is capable of doing.  Not MDC, Emtron, link or anything else that doesn't use the same level of inputs and calculations.

The MAJOR drawback with the factory ECU is the ability to log (easily).  It can be done using EvoScan, but it can't be done internally.   This is the major bonus of the Motec or Emtron (or possibly even Link...i haven't had any experience here) is that you can accurately log the Center Diff control parameters just as easy as everything else in the engine ECU.

Now don't get me wrong, you can certainly achieve great results with an aftermarket ACD solution, and the ability to find someone to tune them is probably easier too....but yeah I've been doing the factory ecu setup for over 10 years now and see no reason to change.

The attachment is a simplified control diagram of the factory ECU.

That logic is pretty much the logic i wrote on the link with maths, VA, and GP Pwm tables. While we made improvements with stock AWD Tuning, the switch to Link unlocked a lot more potential. And at the end of the day you need to exactly know what the center diff is doing when you tune your suspension setup properly. 

[k4nnon]

Hey all. Thanks for the replies and the info. I figured out how to read and write the factory ACD ecu with ecuflash. Decided to purchase an English Racing ACD tune rather than just play with the tuning myself. I figured this to be the best option because they have put in the track time needed to really make a great tuned ACD with the stock computer. HUGE improvement over stock I will say!