Power gains of up to 100HP to the wheel on a stock Supra without the risks of flashing!
The JB4 tuner for the Toyota GR Supra Mk5 is the most advanced plug and play tuning system available for the turbocharged Supra platform. Power gains of up to 80 horsepower to the wheels (100hp crank) are possible on a completely stock vehicle running pump gas with the B58 engine. Vehicles equipped with bolt-on upgrades, higher octane fuel, E85 mixtures, or upgraded turbochargers can achieve even greater gains. Now includes the JB4PRO adapter and free app built in!
No ECU flash required and fully compatible with locked 🔒 ECUs.
The JB4 features a simple plug and play installation harness allowing fast installation and removal while delivering advanced tuning capabilities unavailable with other tuning systems. Features include map switching between stock and performance maps, optional boost gauge displays, boost-by-gear control for improved traction, progressive water/methanol integration, built-in data logging, fault code reading and clearing, optional electronic wastegate control, exhaust flapper control, and many additional advanced tuning features.
Unlike ECU flash tunes, the JB4 requires no staged upgrades or supporting modifications. Install it as your first upgrade and immediately experience stronger acceleration, faster turbo response, and smoother power delivery.
Note: In-dash commands have not yet been developed for the Supra JB4.





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