i just got a new suzuki 450 still stock and a few of friends have 06 yfz 450's with NMotion pipe and intake. ifound that my stock suzuki was was quicker that their yfz's up until four gear then they slowly came by. i am very happy with mine and cant wait till my cherry bomb and exhaust i will keep you posted when i get mine right.

 

i was readin a review in DW and they said the r450 goes just under 70 w stock gearing..the yamaha and honda go like 72-75...it also said the r450 doesnt have teh low end punch teh yamaha does....i found that pretty interesting...i dont doubt u tho...that cherry bomb and exhaust should give u the edge over em...let us know