Knowing When To Shift

[Mach 5]

When racing I use acceleration to know when to shift. If your mph slows and you still have a few thousand rpm left to rev, it’s time to shift.

I was never aware of it until I drove the Aston dp-100.

So I'm confused. Did you answer my question directly?

 

[Serum]

So I'm confused. Did you answer my question directly?

Well with bumper cam the speed and rpm is in your face. Once you know the rpm to shift at, you can use your ears from there. You only have to look once.

 

[Grayfox]

One thing I hate with games after GT1 is they dumbed down the dyno graph for no reason.
In GT1 you had X and Y axis so you knew where the RPM range was or power values.

This is the only image I can find so far.

Having the X axis would help with knowing where each 1,000rpm range is or even 2,000rpm if it is a high RPM engine as you can have a better idea of when the power drops off.
The Y would be nice as well.

 

[gti_sdn]

The best time to shift is when the longitudinal g is the same in the previous gear is the same as the next.
If the longitudinal g drops off before you shift, you lose acceleration.

This guy explains it better than I could.

 

[jean genibrel]

Hi Guys, cars are best shifted at a certain RPM, I've always just up shifted as late as possible but I'm losing time because of this. Can anyone give advice on how to figure out the ideal time to shift?

You are wasting time because the power drops off at the end of the power curve, so you are losing acceleration. Then, you may lose acceleration (torques) by shifting into the higher gear past the torque peak. So, the shifting points should be determined based on 1—the torque curve and 2—the gear ratios of the lower gear to the higher one. By the way, there used to be software available to calculate the shift points. Does anybody know of it?

 

[jean genibrel]

Furthermore, the gears are very important as well in knowing when to shift. Just think if you were to shift normally from first to third. The engine would fall back of the torque peak. Now if you shift from first to second the engine will be more into the torque peak. So the answer is to know the engine torque curve, or at least where the torque peak resides and gear the transmission accordingly.

 

[Meythia]

torque peak

Does not really matter.

Lab / Optimal Upshift RPM

GT ENG!NE / Gran Turismo Sport Database website

gt-engine.com

Peak torque = 6000RPM
Peak power = 6800RPM
Red Line = 7500PRM
Shifting = see above (shortly before redling, much behind peak torque).

If you dont want to calculate but just a general estimation, when to shift depends on your gear ratio but simply said comes down to get as much of the power curve area as possible (for acceleration), so behind peak power always.