Shift Retard on 2JZ-GTE Automatic

[dan_t]

I'm wondering if anyone out there has looked at this before. I have a 2JZ powered Aristo with an Automatic transmission. I would like to wire the EMU in parallel with the OEM ECU so that the Trans still has control for Line Pressure and Shifting Schedules.

The OEM ECU commands a Timing Retard to help keep the trans together (especially on the 2nd gear sprag) and this is a feature I would like to copy. It seems that it could be accomplished with the "Gear Cut" feature on the EMU but I'm struggling to find a "trigger" for this event.

The OEM ECU controls both Engine and Trans in one unit so it has no need to send out an external signal. Does anyone have any idea's about how I could create a trigger? I've heard that the ECU may also close the "Trac" throttle valve - if that's the case, that me be all I need but right now its untested.

Any advise is greatly appreciated!

[Zazzn]

I'm aiming to do something like this very soon, but I don't know how we can retard the timing between shifts. I'm thinking the sports shift or flat shift could help here, but I'm not sure if there is a signal for the stock ECU that we can tap to acknowledge the shift. There must be something we can use though.

[Karel]

I think the OEM 2JZ-GTE uses the secondary Throttle plate to reduce the torq on slip or in shifting. We made the EMU conversion on one automatic Supra, and it works. The stock ECU stil becomes all sensor inputs, the EMU just controls injection, ignition, idle and boostcontrol. We are able to control so accurate, that the OEM ECU is 99% of Time happy with it, and is not trowing error codes. Just in few cases on Idle lights randomly the CheckEngine Light. ........... just an idea