Delphi MT21M ECU Tuning
Engine control unit used in 9 supported models from 1 make.
Harley-Davidson with the Delphi MT21M
All Harley-Davidson tunes- Harley-Davidson 1212023+121AutoTuner
- Harley-Davidson Cruiser models2020+107, 114, 117AutoTuner
- Harley-Davidson Low Rider S&ST2021+114ci, 117AutoTuner
- Harley-Davidson Nightster models2022+1250AutoTuner
- Harley-Davidson Panamerica models2022+1250AutoTuner
- Harley-Davidson Softail models2020+117AutoTuner
- Harley-Davidson Sportster models2022+1250AutoTuner
- Harley-Davidson Touring models2017+107, 114, 117AutoTuner
- Harley-Davidson Trike models2017+107, 114, 117AutoTuner
About Delphi MT21M tuning
The Delphi MT21M engine control unit is supported in 9 models from Harley-Davidson. We read, modify, and flash it with AutoTuner, then verify the result on our Dynojet 424xLC2 in Jenison, MI. A custom calibration optimizes fueling, ignition timing, boost, and torque limits for your exact build.
Don't See Your Vehicle?
These lists cover off-the-shelf tuning platforms. We also do standalone ECU installs and custom calibrations, so reach out and we'll tell you what's possible for your build. Compatibility data last updated 2026-09-24.