[texwayne]

like rdancd816 said, make sure your engine is up to temp before high revs. i personally shift at 3K RPMs until the engine is warmed up. then, it's whatever the situation demands. i hardly ever shift past 6300 RPMs because you can grab a higher gear and still stay around 4K RPMs where the torque peaks. although, i have to admit that i've hit the rev limiter in 1st gear several times just from having too much fun.