pride355:

BTW, initial announced time was 7:29 which Porsche had claimed that it is impossible and they could only done 7:50 with the GTR which leads to a new dialogue between Nissan and Porsche about training Porsche Test drivers.

7:26 time came from new model year car with the Spec V wheels/tires and a few more small changes on the new tarmac.

So what we are talking here, actually is 9 sec which I believe is possible.

Also as I said before Suzuki's GTR could have different alighment and suspension tweaks for the Ring. Even after these alterations, the car can be assumed as STOCK. 

This is correct.  As a GTR owner, you get a choice of three set-ups for the suspension - motorway, fast road or track.  The Cars leave the factory (so I've been told) in 'motorway' set-up to improve tyre life.  At the 1200 mile free service, you get the choice of changing the set-up.  The track set-up dials out a lot of the understeer that is present in the motorway set-up.