The RPM depends on just how much more power your car is making past 6k and how fast you wanna go. My car's power peaks over 6300 rpm with the blower cams I have, so I'll take it to 6500ish at the track to get as much out of it as I can, and around 6200 on the street to keep it safe. But if your car peaks less than 6k, the risk/reward of going over that isn't nearly as much as if it was a little higher up.
The RPM depends on just how much more power your car is making past 6k and how fast you wanna go. My car's power peaks over 6300 rpm with the blower cams I have, so I'll take it to 6500ish at the track to get as much out of it as I can, and around 6200 on the street to keep it safe. But if your car peaks less than 6k, the risk/reward of going over that isn't nearly as much as if it was a little higher up.
I agree. 400-500rpm past peak power is really a good starting point for a car to shift. A lot of other factors come in to play with you curve, gearing, etc. but you don't want to shift at or before peak power.