By now most of you have read my previous posting regarding Porsche own tests using a US-spec R35, it couldn't get within 20 seconds of Nissan's claimed record.

Porsche are saying Nissan "cheated" on their record attempt by using either R-comp tyres, a juiced-up engine or both, but now Nissan has issued their own official rebuttal to the German automaker's allegations - and it intends to introduce hard, physical evidence to support its case.

Nissan's counter-argument to Porsche's claim is that the Bridgestone RE070R tyres fitted to the car they used for their tests aren't quite as soft as the Dunlop SP Sport 600's that were used on Nissan's record-setting R35 (and which are fitted as standard to all base model GT-Rs).

Nissan also raised the issue that Porsche may not have observed the proper running-in procedure for the R35 before conducting its lap attempts, and that the driver they used (a Porsche chassis engineer) wasn't familiar with the methods required to extract "the full capabilities of the GT-R".

If indeed there was any doubt about what tyres Nissan themselves used, the automaker has said that it is more than happy to display the very rubber that was fitted for the 7:29 lap (left), which were sent to tyre manufacturer Sumitomo for promotional purposes after the record time was was set. As for the idea that the GT-R's highly specialised hardware received some judicious fiddling before it went on the track, Kazutoshi Mizuno, chief engineer of the R35, had this to say:

"Testing a car with specialized parts such as unique tires or suspension has no meaning for us. The GT-R was designed from the start to be a supercar that could be driven anywhere, anytime and by anyone. For us, testing the car in standard production specification is far more relevant than creating a one-off vehicle that our customers cannot buy,"

In the case of Porsche vs Nissan, there's no smoke and mirrors obscuring the truth... But I would said both supercar are equally good and potential.

Track Test Video Clip (In Japanese)

Source: Carsguide/GT-R Blog