It really all comes down to the tuning in either car. Given E85 and injectors, boltons on the GT-R it will/should have a slight edge over a stock/tuned 991 turbo/s on just pump gas. E85 carries so many advantages when it comes to performance/tuning/knock prevention that it allows quite less capable cars to perform at quite a higher level than those on pump octane/gas. A tuned 991 Turbo S with intercoolers/exhaust should have no issues taking on a full bolt-on stock motor GT-R on pump gas. R35 stock rods are safe to 600awtq and most leave it there until they open the motor for an internals build, just something to keep in mind.

Dzenno@PTF