Mercedes-AMG GT S breaks 205mph with unofficial tuning kit

While some might decry the move towards turbocharging and ever more electronic control in modern performance cars, there’s little doubt it’s made tuning more accessible than ever.

Nowhere is this more evident than in the highest performance vehicles. German firm performmaster has turned its attention to one of the best – the Mercedes-AMG GT S – and the result has lifted its top speed to 205mph.

Available for both the GT and the GT S, the PEC tuning module can be installed alongside the standard ECU with three OEM plugs, eliminating the need to hack into cables and ensuring the car can be returned to its standard output at any time.

That output increases from 456bhp in the GT and 503bhp in the GT S, to 603bhp from either car. As a result, the standard 189mph and 193mph top speeds are lifted to 205mph.

Acceleration also improves by a healthy margin, dropping the 0-62mph sprint from 4sec in the GT and 3.8sec in the GT S, to 3.6sec. Up to 124mph from rest, the difference is even greater – the tuned model cuts 1.3 seconds from the GT S’s 11.5sec figure.

Similar performance will soon be available in the Mercedes-AMG C63 saloon and estate, too – since both use the same 4-litre, twin-turbocharged ‘hot V’ as the range-topping coupes. Peace of mind for owners comes in the form of a 24-month or 100,000km (62,137 mile) warranty for the entire engine and transmission.

As further example of what simple electronics tuning can achieve, performmaster notes that other packages can take the A45 AMG (and similarly-engined models) to 405bhp – greater even than Mercedes’ own revised A45 – and the CLS 63, E 63 and S 63 AMGs to a healthy 692bhp.