i'm not sure about the exact time, but when you look at your rpm gauge, i think you should shift when the number of the gear turns red. some people do it a little before, when the pointer reaches the redline...
for example, in my bmw 320 e46, it's got like 10 red lights. i shift gears as soon as i can see the last one litting up. some cars have 5 lights, yellow and red, but i think it's the same principle. i always shift when i see the last light :thumb:
The important thing is which gear to take the corner, like for a very tight turn usually u take it with the first gear, but for a normal slow corner mostly 2nd gear, but what i see alot like with gtr 2 ,guys are taking the slow corners with the 3rd gear, maybe to avoid the back slipping away when applying too much gas?
Depends on the car really - if the car has a lot of low down power, such as a Viper you are best off changing gear earlier than normal so you can make the most of the torque. However, if it is something like a Radical, you are best off revving the hell out of it as all the power is high up.
As James said it all depends on the car and the place it develops it max torque and bhp ... plus where you are changing gear, as sometimes a short shift can allow for earlier acceleration and not so much wheelsping coming out of bends ...
I tend to use the straights in a practice session to get a feel for where the power drops off, and try to change just before
Also Evo has an info button with power @rpm details when you are selecting your car (Race has the info somewhere but can't picture where for the minute) ... you can use thsi as a guide