Subaru Torque Control

Below is an example of how the torque control works on a 2008 Subaru STI. The throttle control works identical on BRZ vehicles as well.

For a given Accel pedal position all of the below maps are looked up to finally end up at a desired boost and throttle plate angle. Based on 70% accel pedal at 3200RPM while in S mode. You will see that the target boost is quite low and the throttle angle is also fairly small.

Accel Pedal to desired Torque

Accelerator Pedal @3200RPM	Desired Torque

Accelerator Pedal @3200RPM	Desired Torque
70%	262.1 Nm

Desired Boost A

Desired Torque @3200RPM	Boost Desired

Desired Torque @3200RPM	Boost Desired
262.1 Nm	32 Bar Absolute (0.32 bar of boost)

WG Duty Initial MT

Desired Torque @3200RPM	Initial WG Duty Cycle

Desired Torque @3200RPM	Initial WG Duty Cycle
262.1 Nm	0%

The low wastegate duty cycle requested comes as no surprise given that boost production is so low at that point.

WG Duty Max MT

Desired Torque @3200rpm	Max WG Duty Cycle

Desired Torque @3200rpm	Max WG Duty Cycle
262.1 Nm	0%

Again, the low boost level causes a 0% wastegate duty cycle.

Wide Open Throttle Torque Threshold

WOT Torque at 3200RPM	Proportion of Max Torque (Requested Torque/WOT Torque)

WOT Torque at 3200RPM	Proportion of Max Torque (Requested Torque/WOT Torque)
296 Nm	262.1 Nm (requested) / 296Nm (WOT torque) = .885 Proportion of Max Torque

Desired Torque To Throttle

And finally we see how much throttle the computer will request

Proportion of Max Torque	Desired Torque to Throttle Angle for 3200RPM and 0.885 Proportion of Max Torque

Proportion of Max Torque	Desired Torque to Throttle Angle for 3200RPM and 0.885 Proportion of Max Torque
0.885	~32º

As you can see it can be a bit hard to get your head around, if you need assistance when tuning a specific vehicle please do not hesitate to contact us and we will try and help as much as we can.