I was invited to a GR Selections event where Toyota brought a bunch of GR Yaris with the different calibrations. All cars had the torque bump, but differing power steering, throttle mapping, AWD control, etc. Slalom, circle skid pad, etc. After driving each car, I sat down with a development engineer and discussed what I thought about the calibration change while they aggressively took notes.
The 20nm bump is very noticeable, even on a stock car. It's essentially the same engine calibration as the GRMN (JDM). With a good exhaust it's more like a 30nm bump, which brings my JDM car to 400nm. I also noticed that power in the top end doesn't fall off as much. Boost carries out and it has more grunt from 3,250 rpm to red line. But this could very well be a JDM thing.
The throttle mapping "high response," which is what I opted for, is awesome on fast winding, but way too aggressive for gymkhana. The "control" is more linear than the stock calibration and what most people doing gymkhana opt for. Below about 3,000rpm, the calibration is the same as stock for all options.
I couldn't really tell a difference between the 55/45 and stock 50/50, but the 45/55 definitely makes the car want to push at throttle application mid-corner than the other settings, so I just left it alone.
People who do gymkhana want a lighter power steering. I didn't like it for fast winding, and certainly don't want it heavier, so opted to leave it alone.
Now, 'the dealer" has nothing to do with calibrating the software in the car. You have to specify what you want (in Japan that's done online through Kinto). Then you tell them what dealer of GR Garage will do the flash. Toyota (the big guy) does the calibration for your car's VIN, and the new calibration is registered to that VIN. Then the dealer or GR Garage calls you when Toyota says it's ready, you bring the car and they simply plug into the car with GTS, and the ECU is reflashed from Toyota with the new calibration. The same procedure as if you were changing the engine controller.
At any time in the future, if the ECU is replaced, the cal file that's flashed to the new controller will be the upgraded one, as that's the cal file for that VIN. You can opt to change it back to original, but again, has to be done through Toyota and then the cal flashed by the dealer, etc.
Came with official paperwork and a sticker in the door by the data plate.
*Edit. Because I only opted for the torque and throttle cal change, it was only ¥88,000. Worth it in my opinion, especially the throttle change, and it's all stock Toyota. Literally the stock calibration for that car.
