God! That is so laughable. It does not even deserve an answer since it implies Lexus as a cheat without credibility. Please don't start that up yet again (with the LFA interior being the previous).
For one, LFA is putting down 571 PS (563 HP) specifically 117 HP/Liter already. It cannot go any higher than that naturally aspirated so your claim of 100 HP more is completely ridiculous.
Lexus never marketed LFA on lap times or 1/4 mile times. It was always on the merit of how driver oriented the car was, which is why it never came with high-grip or racing compound tires.
It was done in the middle of "driver experience" event with lots of owners and press journalists being present in the event. Chris Harris and several other journalists were doing test drives on the very same car and mentioned on their blog had actually driven and also seen the car when Akira Iida took the car for the record lap. Chris Harris broke the news of the 7:14 on his blog days before Lexus came out with a statement. It was on stock Potenza street tires. Iida has made clear himself several times that the car was nothing, but 100% stock. Chris Harris was so obsessed fighting with the people mocking it that only his blog from those days need to be seen to be believed.
The biggest thing is Saurma himself had mentioned the 7:14 in the supertest and also admitted that a much faster lap time is entirely possible and the only reason why he got only a 7:34 was because he did not have the standard prep time that he normally gets for every car for his lap in the LFA since the car had to be returned.
Alden Hajdzec and Sandor Van Ees on their debut lap in the LFA achieved 285 km/h on Dottinger Hohe uphill while Saurma got the same 284 km/h in his full attack lap time while Iida did 290 km/h top speed on the same segment.
Even the standard LFA lap time of 7:38 even on the flimsy tires was slower than Sascha Bert's lap time in exactly the same LFA, which was done with an editor sitting in the passenger seat and also for the full longer 20.8 km version of Nurburgring.
To be honest, the lap time of LFA NE being the same as an R8 GT is what defies reality considering a standard LFA in two head-to-head comparisons (Motor Trend, AMS Germany) on the same flimsy tires matched or beat the R8 GT lap times on Corsas.
If you don't want to accept it then by all means don't, but don't raise question that defy logic like that.
How do anyone outside Lexus know they were not putting 100 more hp, slick tires or running the counter clock a bit faster just to amaze the armchair race bigrade?
I insist, until there's no official governing entity checking every car and taking times, every time is a claim, manufacturers and magazine's
Regards