JB4 Tuner — Toyota GR Supra Mk5 (A90/A91)
Up to 100 wheel horsepower on pump gas, on a stock car, without flashing the ECU. The JB4 works through the Supra's sensor network and CANbus, so the DME never sees a modified tune — which is what keeps it compatible with locked ECUs and factory software updates. Plugs in under the hood in about 20 minutes and comes back off just as fast.
JB4 or JB4PRO?
Both include the JB4PRO Bluetooth adapter and the free app. Wireless map switching, live gauges, datalogging and firmware updates from your phone are standard either way — the PRO is not "the one with Bluetooth."
The JB4PRO is a different board built for heavily modified cars. On top of everything the standard JB4 does, it adds:
- Direct ethanol sensor control
- Port injection / CPI / WMI control via the PnP add-on harness
- Fuel pressure control for advanced tuning on ethanol mixtures — built in, no upgrade kit needed
- Onboard datalogging memory
- Additional high-current outputs for extra pumps, relays and solenoids
- Additional inputs for monitoring external sensors
- Bluetooth and memory on the board itself rather than via the adapter
- CANbus integration with flash tuning
Stock or bolt-ons? The standard JB4 is the right call. Chasing big E85 numbers or adding port injection? Go PRO.
What it does
- Multiple switchable maps, including E85 ethanol blends
- Boost-by-gear control for traction management
- Live gauges, datalogging, fault code read and clear
- Fully reversible and not VIN-locked — it moves to your next car
- Free firmware updates · 5-year warranty · designed and assembled in the USA
VEHICLE APPLICATIONS
| Make / Model | Chassis | Engine | Years |
|---|---|---|---|
| Toyota GR Supra Mk5 3.0 | A90 / A91 | B58 3.0L I6 Turbo | 2020–2026 |
| Toyota GR Supra Mk5 2.0 | A90 / A91 | B48 2.0L I4 Turbo | 2020–2026 |
Going E85
The Fuel-It Flex Fuel Kit lets the tune read your actual ethanol content instead of guessing — worth having on any blended setup.
On a standard JB4, add the JB4 Fuel Pressure Upgrade Kit for direct fuel pressure and fuel trim control. Skip it if you're buying the JB4PRO — that's already built in.
Prefer a flash tune?
We also carry the MHD Super License and the bootmod3 tune for the Supra B58.