Golf GTI JB4 and meth injection making more power than a Golf R. The JB4 is a Golf GTI tuning box which connects to multiple sensors across the engine and the cars canbus data via the OBD port.
The JB4 uses this real time engine data for tuning but also safety. This allows the JB4 to make more power than other tunes but also with safety systems in place.
With meth injection the Golf GTI can safely make more power than the Golf R or the other cars in its segment.