A Porsche product chief has accused Nissan of cheating to set the GT-R’s record-breaking lap time around the Nurburgring in April.Engineers from the German sports car maker have been running tests at the ‘Ring and could not get within 25 seconds of Nissan’s claimed 7:29 second lap time. “For us, it’s not clear how this time is possible” August Achleitner, product boss for the 911, told the Australian press. “This wonder car with 7:29 could not have been a regular series production car… We imagine with this Nissan used other tyres.” Achleitner apparently said the GT-R’s time – which was set with ex-F1 driver Toshio Suzuki at the wheel - could only have been achieved if the car was running semi-slicks. Porsche apparently purchased its own Nissan GT-R in the US and has pitted it in back-to-back tests against a standard GT2 and a 911 Turbo. With Porsche’s driver behind the wheel – who wasn’t hot lap specialist Walter Rohrl – the GT-R apparently set a lap time of 7 minutes 54 seconds. On the same day, the 911 Turbo managed 7:38 and the GT2 clocked 7:34, Achleitner said. Back in April, Nissan was keen to draw attention to the GT-R’s pace around the Nurburgring, with a lap time it insisted was set by a standard factory car. But many commentators are sceptical about the value of comparing Nordschleife times, in case manufacturers have fettled with their car.