Nah .. you can't .. the TCU is not located in the main engine ECU ..

All those you mentioned are located in other ECUs .. the info is then sent to the engine ECU to have the desired output ..

 

I assumed the TCU is in the trans. I don't know what info the TCU would need from the ECU besides maybe the gas pedal position, brake, and engine RPM (if it didn't have it's own integrated sensor).

 

gunzo says its the other way around, ECU makes decisions (pull timing/boost cut/send signal back to TCU to disengage clutches or whatever the safety mechanism is) based on several inputs,

if thats the case then we should be able to discover a table (s) for the TCUY input and alter values to bump up the torque limit

or maybe, just maybe there is a training video or manual floating around describing in detail how ecu and tcu work together (doubtful though since any problems with the tranny and it has to go back to mitsu for replacement)

 

When ttp tuned the r/a, and found the limit of the TC-sst, it really sounded to me like it was the logic system in the trans that caused it to "slip", or whatever it did. If it was the ECU that controlled it, the engine would have probably cut itself back automatically (this would mean the engine couldn't be tuned). Also, if the ecu was sending such commands to the tcu, it (the ecu) would have to be aware oh how much power the engine is making. So, I would imagine that the torque limit of the trans is controlled by the tcu.

 

You know what I have noticed in the transmission...
In sports mode the tranny keeps the engine where all the torque is 3k-4k rpms.

For example i'm going 60 mph. If i'm in sports mode the tranny goes to 5th gear. If your in sports mode and just normal driving on the highway. The TCU will not let the motor drop below 3000rpms. I wonder how the super sport modes in the MR react? Maybe we need that mode to mod the RA.

Also, since the tuning shifted the power up to 3500-4500rpms the trans is reacting strangely. I think you have to tune them together. The ecu and tcu.

Also, the one thing that is interesting is people have been saying that maybe you can tune the clamping force of the clutches??? That's something interesting!!
Someone's gotta find that out. Where's all the baller MR guys at??

 

OK .. this is what the SST does

It sends a torque request code to the ECU .. the ECU reference a table, compares that value against the actual torque (airflow) the engine is producing and then tells the TCU if the torque request is OK or rejected ..
If it's rejected .. you get your infamous CEL ..

There is a possibility that the table is also in the TCU and it protects the gearbox when the requested number is exceeded .. but it seems like to me (for now) this table is extracted from the ECU and sent to the gearbox ..


BOM's Evo .. S-Sport mode, the gearbox will not shift until 7000rpms .. and it'll downshift so you're always right at the fatend of the torque

3-4000rpms is the same as the SPORT mode on the Evo

 

Hmmm.. Torque request code?

I could see the ECU and TCU having matching tables to trigger an error if the expected values do not occur.

So the engine might measure it's own power output by comparing engine RPM to airflow? Hmmmmmm..... How much of the Evo's ecu program is known?

 

Gunzo is actually disassembling the Mitsubishi ECU so he isn't taking guesses, he is actually following the code references, etc.

I've been dyno and street tuning and logging a MR (and a ralliart as soon as I get my hands on one) and I see the same things that he is talking about. We are currently working together to better understand and tune the ECU and the SST to work better together.

The torque, airflow and SST tables follow TPS x RPM and units (most likely airflow and load calculations).

 

Any thoughts on why Mitsu would have implemented such software?

How did you obtain info regarding the ECU? Are there schematics available? Are you trying to understand the assembly code? I'm interested if you're willing to share any info. Keep up the good work!

 

so supposedly this Zchip from ttp, wont do much due to the limit. and all mods shud be held off until the tranny is cracked?

 

The ZChip has proven to add a notable power and torque gain to an otherwise stock Ralliart '09. The dynosheets are posted in another thread.

 

yes, equivalent to say stage1, but the torque limit is what will prevent z-chip and any other tuning method to go any further, until it can be over ridden in torque (airflow) tables

i belive cobb software can do it, curious of any cobb tuners can chime in and let us in on whether they have done any of this with a custom MR tune?

 

Gearbox protection ?? New technology ?? Can you ask something that I can answer ??

I obtain the information from looking at the ROMs that people gather when they extract it from the ECU ..

The RA ECU is quite close .. so I can say whatever I find out on the X probably remains the same for the RA ..

I'm experimenting at the same time I'm stripping the ROM .. and thats the only way I can figure out what goes on .. and thats also the reason why it's slow ..

One thing I can warn you guys is .. when you increase the power, you'll reach a point where the SST attempts a shift and the engine cuts so much power you'd think something is broke .. the car literally slows down, hurls you forward, engages the next gear and slams you back .. so don't be alarmed when that happens ..

 

Interesting... You think it's using some kind of maps to determine how it'll cut the appropriate amount of RPMs?

 

Yes it does I believe .. think I found it .. just need to test somemore .. problem doesn't always happens .. it only happens under part throttle under certain conditions .. but I fixed 1 thing .. it always happens around 30% throttle