Racing Transmission¶

CORE ECU provides native support for racing transmissions, including the Powerglide and Turbo 400, for drag racing applications. The following steps outline the process for configuring and enabling Racing Transmission control.

Racing Transmission Wiring Setup¶

The below step-based procedures outline how to wire your powerglide and Turbo 400 transmission onto CORE.

1. Connect the I/O sub harness to your Drive-by-Cable or Drive-by-Wire harness.

   

2. Locate the dump valve(s), typically mounted on the passenger side of the transmission case or on the tail-shaft housing.

3. Connect one dump valve wire to the 12V ignition source. Connect the other wire to one of the LOW SIDE DRIVE outputs on the I/O sub harness; polarity does not matter. For PWM applications, wire the dump valve through a solid state relay.

   Note

   The image below shows the 2 wires coming out of the dump valve solenoid.

   

   Note

   The diagram below shows the recommended wiring configuration for connecting the dump valve to a solid state relay (SSR).

   

4. Locate the transbrake solenoid on the transmission. On Powerglide applications, it is typically located on the rear of the transmission case. On the 400 applications, it is located on the passenger side of the case, just rear of the bellhousing.

   

5. Ground the black transbrake wire to a clean ground point. If grounding to the transmission case, verify that the case is properly grounded to the battery/chassis.

6. Run the other wire of the transbrake to the output of the SSR, use the below diagram as reference.

   

   Note

   Transbrakes are typically used in drag race applications to enable a consistent launch by coupling the reverse and 1^st gear circuits to hold the vehicle at the starting line. We recommend using a transbrake system with Powerglide or turbo 400 transmissions to lock the transmission in low and reverse gears simultaneously.

7. If your shifter is equipped with a P/N or Position switch, splice them onto your preferred I/O sub harness wires.

   Note

   • Transbrake activation requires a momentary button, typically mounted on the steering wheel or shifter, wired to one of the digital input / toggle switch inputs. Wire one terminal of the button to a clean ground and the other to the desired CORE input.
   • The dump valve does not require its own button. Its output is controlled by the ECU based on the transbrake activation input, along with a user-definable table for dump valve characteristics.

8. Your powerglide and/or Turbo 400 transmission is now wired onto CORE.

Trans-brake VCM Live Setup¶

1. Download the latest version of VCM Live Beta here.

2. Open VCM Live and click the drop down arrow in the group layout tab and select Transmission.

   

3. Select the Trans Config tab in the top menu bar and locate the Trans-brake Control Enabled parameter and change the value to Yes to enable Transbrake control.

   

4. Once transbrake control is enabled, a Trans-brake tab will appear. In this tab, select the output controlling the transbrake relay from the first box.

   

5. Next to this box is the Trans-brake Switch option. Enable this to configure the transbrake trigger. This also allows you to indicate to CORE whether a bump button is fitted.

   

6. Once enabled, a Trans-brake Switch tab will appear. Use this tab to specify which input the transbrake is wired to.

   

7. Once all of the above parameters are enabled, transbrake is ready to be utilized.

Racing Transmission VCM Live Setup¶

1. Select the Trans Config tab and change the parameter Transmission Type to RacingTransmission.

   

2. Select the Racing Trans Setup tab and adjust the Racing Transmission - Number Of Gears parameter to the number of gears your transmission has.

3. Select the Racing Transmission Up Shift Activation Mode drop down arrow and select your preferred upshift mode method.

   

   Note

   • HP Tuners CORE supports five upshift activation modes for Turbo 400 and Powerglide transmissions.
   • HP Tuners recommends a momentary switch.

   1. If you select switch activation for your upshift mode, configure the parameters below accordingly.

      

      Note

      Each successful activation of the racing transmission's up-shift switch shifts the transmission from the current gear to the next higher gear.

   2. If you select time activation for your upshift mode, configure the parameters below accordingly.

      

      Note

      • Following a successful vehicle launch, CORE initiates a timer and performs upshifts according to your predefined shift times.
      • For example, starting from the timer's initiation (i.e., after a successful vehicle launch), the transmission shifts from Gear 1 → 2 at 2 seconds, from Gear 2 → 3 at 4 seconds, and so on.
      • In addition to a successful vehicle launch, engine speed must exceed the Racing Transmission Timer Activation Engine Speed parameter for the Racing Transmission Timer to start.

   3. If you select RPM activation for your upshift mode, configure the parameters below accordingly.

      

      Note

      • For example, after a successful vehicle launch, the transmission shifts from Gear 1 → 2 at 3,000 RPM, from Gear 2 → 3 at 3,500 RPM, and so on.

   4. If you select Time & RPM activation for your upshift mode, configure each of the above paramters for both time and RPM accordingly.

   5. If you select Time or RPM activation for your upshift mode, configure each of the above paramters for both time and RPM accordingly.

   Note

   The upshift is triggered by whichever condition, time or RPM, is met first.

4. Locate the Racing Transmission Up Shift Time parameters and adjust the below parameters accordingly.

   Note

   • Once triggered by any of the five activation methods described above, the upshift remains active for a defined duration, this duration can be calibrated with the below parameters.
   • Once an upshift is triggered, no additional upshifts are allowed for the duration of the upshift time.

   

5. Locate the Racing Transmission After Shift Inactive parameters and adjust the below parameters accordingly.

   Note

   Upon successful completion of a gear shift, CORE prevents any subsequent upshifts for a defined period, during this time, the gear shift functions remains inactive, these inactive times can be calibrated with the below parameters.

   

6. Locate the Racing Transmission Reset Mode parameter and under the value column select your preferred method on how you would like to reset your transmission.

   

   1. If you select to reset your transmission through time, ensure to adjust the Racing Transmission Reset Time parameter to your desired time.

   2. If you select to reset your transmission through vehicle speed, ensure to adjust the Racing Transmission Reset Vehicle Speed to your desired mph.

7. Locate the Racing Transmission Pedaling Timer Mode parameter and select if you want to continue running time or pausing it.

   Note

   • After a successful vehicle launch, CORE starts the "Racing Transmission Timer". During a run, if throttle position falls below the "Racing Transmission Pedaling Activation Throttle Position" threshold, CORE interprets this as pedaling. Depending on the selected calibration, CORE either continues running the timer or pauses it.
   • This feature applies only to the Time, Time & RPM, and Time or RPM activation modes. These are the modes that use the "Racing Transmission Timer" for gear upshifts.

   

   1. Racing Transmission Timer Continous: The racing transmission timer continues to run even if the throttle position falls below the defined threshold during the run.

   2. Racing Transmission Timer Pause: The racing transmission timer is paused (frozen) when the throttle position falls below the defined threshold.

8. Locate the Racing Transmission Ignition Retard Enabled and Racing Transmission Ignition Cut Enabled parameters. Enable the desired option by clicking the drop-down arrow and selecting Yes if you want to retard the ignition or completely cut ignition during Racing Transmission gear upshifts.

   1. Utilize the below tables to configure ignition retard.

      

   2. Utilize the below parameters to configure ignition cut times.

      

   Note

   Additionally, CORE allows the ignition cut to be delayed by a defined amount of time from the moment the upshift is triggered. Utilize the parameters below to configure your ignition cut delay up shift time.

   

9. Locate and adjust the below parameters to configure the output solenoid channel, duty cycle, and frequency.

   

   Note

   The racing transmission gear-shift solenoid can operate in two different modes: Off–On–Off and On–Off–On. CORE supports both modes via a single parameter: Racing Transmission Actuator Output Inverted.

   1. Off–On–Off: Set this parameter to No. In this mode, the solenoid is Off (0% duty cycle) when no shift is occurring, and On (100% duty cycle) during a gear shift.

   2. On–Off–On: Set this parameter to Yes. In this mode, the solenoid is On (100% duty cycle) when no shift is occurring, and Off (0% duty cycle) during a gear shift.

Racing Transmission Tuning Setup¶

1. Locate the Sensors Input Triggers parameter.

2. Once located, adjust the output value to activate above 6,900 RPM and deactivate at 6,800 RPM.

   Note

   On a Turbo 400 transmission, this allows the pin to pop back up and be ready to make the 2-3 shift.