To turn the engine's hardware into usable, drivable, efficient power through the ECU, and to implement the driver aids that convert that power into lap time.
A MoTeC M150 running the GPRP package under an M1 Development licence (V1.4.1), which gives full access to the firmware, custom control system implementation, custom sensor integration, full control over CAN receive and transmit, and built-in traction control, launch control, gearbox control, datalogging and electronic throttle. Fuelling is volumetric-efficiency based in speed-density mode using a Bosch TMAP sensor and an LSU 4.9 lambda sensor, with inlet manifold air density as the reference. Ignition is mapped against cylinder air mass rather than manifold pressure, because MBT correlates more closely with cylinder air mass and that makes a revised manifold package require far less re-tuning. Traction control limits rear wheel slip during acceleration by capping engine speed and applying progressive ignition and fuel cuts. Launch control does the same from 0-20 mph using ignition retard first and cuts only when the error grows too large. Calibration carries no costed parts; it is labour, and it is why the subsystem appears in the taxonomy with zero BOM rows.
Calibrate on the test stand, validate on track. The AC motor engine dyno gives precise speed control, independent closed-loop control of coolant and oil temperature, ambient air temperature control for environmental correction calibration, and a concentrically twisted shielded harness with monitored supply and ground reference voltages. None of that is available on the car. Event-specific targets. Because the power-against-efficiency trade differs by event, lambda target is set per event: 0.87 lambda under full load for autocross and acceleration, 1.00 lambda for endurance. Design around the single points of failure. The MAP sensor is one; an alpha-n table estimating manifold pressure from throttle position and engine speed both covers a MAP failure and predicts steady-state manifold pressure during fast transients. 1. Tune VE at steady state across every combination of engine speed and manifold pressure from 1,500 to 15,250 rpm, with a sound-compliant idle at 1,850 rpm. 2. Validate the VE map under transient conditions with ramp runs from 4,500 to 15,500 rpm. 3. Sweep lambda target at WOT at peak power speed from 1.02 to 0.685, logging torque and fuel flow, to find best torque and best efficiency points. 4. Sweep ignition angle from -10 deg off the base map at fixed speed and cylinder air mass combinations, logging torque to find MBT. Performed on 100 octane, with a margin from MBT held when running 93 octane. 5. Calibrate injection timing by sweeping injection angle and logging torque; below 6,000 rpm the choice is set by engine stability, above 7,000 rpm by best performance. 6. Tune traction control by scaling a wide range of slip limits linearly across switch positions 1-7, then narrowing to a 5-10% range using driver feedback and data, with a lateral acceleration compensation that lowers the slip target at high speed and raises it at low speed. 7. Tune launch control on a competition-spec surface, sweeping initial launch rpm and slip profiles with optical timing gates, longitudinal acceleration, slip data and cut data as feedback.
- Use the engine test stand to develop calibration improvements for engine efficiency and drivability. - Reduce year-to-year ignition calibration time. Cylinder-airmass-based ignition mapping is the mechanism. - Provide consistent torque application out of overrun by keeping injector pulse width above the ballistic region (minimum 1.9 ms). - Linearise torque output against pedal position, since throttle plate position and torque are not linearly related. - Deliver measurable event gains. Launch control took acceleration runs from a 4.319-4.735 s spread down to 4.154-4.279 s.
- The MAP sensor is a single point of failure that results in engine shutdown. Mitigated with the alpha-n estimate table. - Knock detection. Acoustic methods are limited; the team is developing ionic current knock detection through Mitsubishi H6T60271 coils with integrated IGBT and bias/conditioning circuitry, which isolates individual cylinders, works across the whole speed range, minimises speed-of-sound effects on the sampling window, and detects misfires. - Fuel density assumption. Before the fuel temperature sensor, a default 30 C was assumed, which could cause a lean condition when measured fuel temperature reached 51 C.
MoTeC M1 Build for firmware and control system development, M1 Tune for calibration, i2 Pro for analysis. AC motor engine dyno with National Instruments RIO hardware and LabVIEW. Bosch TMAP and LSU 4.9 sensors. Optical timing gates for launch tuning. Planned: Kistler 6054C in-cylinder pressure sensor with National Instruments high-speed acquisition for combustion analysis.