HP equals heat! IMO, any R3 making over 220 RWHP should be using colder spark plugs to help dissipate the extra heat produced. I use Denso Iridium IX27B, one range colder than stock for the R3. Denso's tiny iridium electrode means no quenching, and actually BETTER durability and conductivity (firing power). These benefits can be also be found in the Denso plug for normal heat range R3s (including triple filter and cam bikes)... the Denso IX24B plug. Highly recommended.

http://www.densoiridium.com/patentedtechnology.php