for sport 600s: y = -4.9422x^6 + 138.75x^5 - 1582.6x^4 + 9358x^3 - 30193x^2 + 50525x - 34271, index of determination .9993. integral from 2.5 to 6.5 = 1565
for sport 500s: y = -2.7733x^6 + 75.106x^5 - 824.87x^4 + 4685.8x^3 - 14488x^2 + 23216x - 15041, index of determination .9993 integral from 2.5 to 6.5 = 1246
the differnce in net hp was 319 hp. distibuted across the 2.5k - 6.5k rpm range, the sport 600s avg 80 more hp than the sport 500s.