Description
Weistec Engineering ECU tune for the McLaren 625C and 650S (2014-2017) with the Twin Turbo 3.8L V8 (M838T). Weistec’s crank figures put the tuned engine at 730 hp and 652 lb-ft, up from 641 hp and 500 lb-ft stock, from a recalibration of the factory ECU software.
Key Features:
- Up to +89 hp / +152 lb-ft: Weistec’s crank estimate of 730 hp and 652 lb-ft, from Dynojet testing; real gains depend on fuel, conditions and supporting modifications.
- Stage calibrations: W.1 (Stock Vehicle) and W.2 (Race Exhaust fitted), so the calibration matches the hardware on your car.
- Reflash of the factory ECU: the original module is recalibrated rather than replaced with a stand-alone or piggyback unit.
- What changes: improved throttle response, optimized fuel and spark, increased boost and top speed limiter removed.
- Tuning method: Cypher Pro Dealer: installed through a certified Weistec Cypher Pro dealer.
- Burble & pops available: deceleration burble can be added to the calibration on request.
Fitment:
- McLaren 625C 2015-2016 (Base, Spider) – Twin Turbo 3.8L V8 (M838T)
- McLaren 650S 2014-2017 (Base, Spider) – Twin Turbo 3.8L V8 (M838T)
Not legal for sale or use on pollution-controlled motor vehicles; intended for competition use. Talk to us before ordering to confirm the right stage and tuning method for your car.

Reviews
There are no reviews yet.