This becomes a difficult and touchy subject.
We know that Alois does do a motor tear down for his 590 Nardo kit and
above and who could argue other than the fact that there are quite a few
higher powered cars now running around on stock internals (Mine will soon be
one of them). It was a financial decision for me as it is for others, tearing into the motor costs roughly $15k US (and up, depending on what you do once inside), ironically this is the exact cost to replace an entire motor as
displayed by Cpu77 recently. Time will tell and also if us "high powered,
stock internal folks" use our boost and high octane wisely...this can make a huge differnce. I for one will be running lower boost than some of the Kaboom crowd. I would think (I am no expert) that your set-up should be
a great one and as long as prudence is used, your GT2 will have a long and
happy life.

Marty

 

600 crank bhp is the absolute limit unless you are running race fuel and have the ability to alter the map (which a lot of the US guys do, which is why claims of 700hp+ on stock internals are being made) Ruf found that when boost was upped and sustained, the stock rods would bend at about this figure.

99RON is the equivalent of 94MON (american standard) i believe alot of the racing fuel over in states is 100+, which would be a very high ron rating....

Also think, VERY seriously about where you would have the car mapped....unless you fancy having silly torque numbers...

 

Pmsl probably dms but i know exactly where your going with that

 

I think you're good to at least 700 crank. 600 is well below that. I run something close to 600 with minor bolt-ons and primarily 91 octane, Unless I know I'm going to the track, then I run 101 just to be safe under extended load.

Only RUF recommends a rebuild at 690 HP and they are notoriously conservative.

Craig had posted a good thread a while back regarding not using more octane than is necessary because it has tendency to fill your engine with carbon (unburned fuel) due to the higher and slower flash point and burn.