SRT WK2 — Stage 2 ECU & TCU Tune
- 18% power increase to 260kW
- 17% torque increase to 420Nm
- Improved midrange power delivery
- Enhanced launch control performance
- Optimized converter lockup behavior
- Refined shift characteristics
This 2018 Grand Cherokee SRT came in with headers, full exhaust, and intake already fitted. The brief was to free up the naturally aspirated 6.4L through exhaust cam timing adjustments and manifold runner optimisation, then sort the transmission to handle the extra load.
Factory ECU tuning brought power from 220 kW to 260 kW at the wheels, with torque landing at 420 Nm. The TCU side received converter lockup tuning and revised shift properties to hold gears longer and put the power down cleanly. Launch control was added for the strip.
The customer reported solid mid-range pull on 98 RON and noted the transmission behaviour is much sharper without being harsh around town. A proper Stage 2 package for the big HEMI on pump fuel.
Does the 8-speed ZF handle the extra torque reliably?
With converter lockup tuning and optimised shift maps, the factory ZF in the WK2 copes well at this output level. The TCU calibration manages slip and line pressure to suit the revised torque curve.
What does exhaust cam tuning actually change on the HEMI?
We adjust cam phasing within the VVT range to broaden the torque curve and improve exhaust scavenging, especially with headers fitted. Combined with manifold runner length optimisation, it extracts meaningful gains without touching hardware.
Is this tune suitable for daily driving and towing?
Yes. The power delivery remains linear and the TCU calibration suits normal driving. Torque management is retained for driveline protection, so occasional towing within GVM is fine.
This calibration was developed for a workshop like yours
The Jeep SRT above was calibrated by Protunes for a partner workshop — they did the vehicle work and kept their customer; we did the calibration engineering on the Factory. Add professional ECU and TCU calibration to your workshop without employing a calibration engineer.
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