Full Throttle Shift (FTS) is an extension of the Launch Control concept, allowing for a secondary rev limit while the vehicle is in motion. This feature enables faster gear changes by maintaining boost pressure and engine RPM during the shift sequence.

Implementation Overview#

FTS functions by modifying the existing rev limiter logic to utilize a secondary limit threshold triggered by a digital input. This input is typically tied to a clutch-mounted switch.

Hardware Requirements#

To implement FTS, you must install a switch that detects clutch pedal engagement.

• Switch Selection: For vehicles not equipped with cruise control, the factory cruise control clutch switch is the most straightforward mounting solution.
• Wiring:
  • Connect one side of the switch to a chassis ground.
  • Connect the opposing side of the switch to the designated digital input pin on the ECU.

Tip

Pin B7 (off 00211h.5) is a common and recommended digital input for FTS implementation on OBD1 ECUs.

ECU Configuration#

The implementation requires modification of the ECU firmware to recognize the clutch switch input and apply the secondary rev limit.

1. Firmware Modification: Update the ECU assembly code to include the FTS routine. This routine must monitor the state of the chosen digital input pin.
2. Logic Integration: Hook the existing rev limiter code to reference the secondary limit when the clutch switch signal is active (grounded).
3. Calibration: Define the secondary RPM threshold within the ROM to suit the specific engine and turbocharger setup.

Warning

Improper calibration of the FTS rev limit can lead to engine damage. Ensure the secondary limit is set to an appropriate RPM range that prevents engine over-revving while maintaining sufficient turbocharger spool.