German tuners 9ff have gone to work on the Porsche 911 GT2, squeezing 665bhp from its 3.6-litre flat six with a series of upgrades.
The firm has added a pair of V670 turbos, a new intake manifold and a new exhaust system with a two-stage boost valve.
The ECU has also been modified and the rev-limits been increased to 7200rpm.
The new engine set-up produces 665bhp and 590lb ft torque, compared with the standard GT2’s 522bhp and 500lb ft.
That means the 9ff GT2 sprints from 0 to 62mph in 3.6 seconds - the same as the standard car - but will reach 124mph from standstill in a crushing 9.6 seconds.