Union Flax Tuning
Every Union Flax model, engine, and controller we can tune, 2020+.
Union Flax
1 supported vehicle via AutoTuner
Select Your Union Flax Model
Union Flax ECUs and TCUs
Union Flax tuning at Rapid Racing
We support 1 Union Flax vehicle across 1 model, covering model years 2020+, through AutoTuner. That includes diesel powertrains and 1 engine and transmission controller.
Each Union Flax tune is calibrated for your exact hardware and fuel, then verified with real data on our Dynojet 424xLC2 in Jenison, MI, serving Grand Rapids and West Michigan. Not sure which controller you have? Browse all supported ECUs or ask us.
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.