Thank you the answers.
Can a mod shut this thread down?
Post your timeslip, most likely it’s your reaction, launch, and 60ft times that dictate the quality of your run.
When I dynoed my 92 gsr, I saw horrible torque below vtec. 8000rpm shifts will always be best to ensure the engine never falls out of vtec.
Your launch rpm should also be high enough so that the revs don’t bog down at the clutch drop. Bog down means that the revs don’t fall too much from the tire slipping to catch phase. I don’t have any data except they are best when well above 3500rpm.
For the best acceleration you want to maximize horsepower at the wheels. So shift when you’ll be putting out more horsepower in the higher gear.
Another way to put it is that you want to maximize torque at the wheels, so you should shift when the torque at the current rpm multiplied by the gear ratio you are in is less than the torque at the rpm you would drop to multiplied by the gear ratio you would be shifting into.
In the case of the GS-R, that means shifting as close to fuel cut as you can manage in most gears.