When is the optimal time to shift?

[WPF1_1980]

In some cars, usually lower end GR.3 you can get more speed/power by shifting well before the red line. before the power drops off. Does GT Sport show you the power curve anywhere to better find out exactly where you should be shifting before power lose?

I know they showed this to use in GT5, so I assume this type of info is somewhere???

 

[TenderLoins]

Look in the car settings for the power curve. It will show the RPM number where the particular car makes peak power.

 

[jimbo197]

My uninformed view was - I thought the point of the rev limiter was to keep you to the peak usable power without damaging engine.

Surely you need to factor in the gear you are going to as well, as if you were to change when you start to lose 0.01% power, you might change in to a gear that's getting 20% less power??

I've never watched a European/world fastest GT sport lap where they shift short of the limiter, and can imagine this only happens in muscle cars with huge torque and crappy tyres.

I know my above comment is probably nonsense but I'd genuinely like to know answer.

 

[rex1825]

It is basically where power is at the max, torque starts to drop off and you basically start loosing accel...

 

[Darwock]

In that Lewis Hamilton reference lap he said for some corners you want to short shift. I have never understood short shifting, I tried to google it a while back and all the advice I found was "short shifting is bad".

Clearly that's not the case?

 

[TomPyke]

Short shifting is good sometimes if you don’t want to spin the car - depending on the cars characteristics.

Drops the revs so it doesn’t slide but just drives out smoothly

 

[Vader86]

Generally in real racing I try to shift within 500rpm over the HP peak RPM. That goes for both drag and autocross that I used to do a lot of, though some corners a short shift is required depending on the course. I rarely get to do HPDEs any more that would give me more track.

 

[rex1825]

Here is nice example of a car where you basically don't need to shift in 2nd, or better to say, you lose too much time shifting from 3rd to 2nd, and gaining time if you leave car in 3rd... The Toyota 86GT has really sloppy manual gearbox, especially from 1st to 2nd, it needs ages, a little less from 2nd to 3rd...

On other hand, the Mazda 6, the 4WD diesel car in GTS is a short shifter all the time, you basically in that car never go over 4200rpm, because you will lose a lot of time doing so, it has no power there...

Then again, as some of the people mentioned here, sometimes short shifting is needed to hold car stable, sometimes even overrev is needed to not lose time in shifting... it all depends of track layout, situation you are currently in etc...

And if you really mean what short shifting is, it is basically shifting to next gear much much earlier where engine hasn't build up torque nor power (in diesel engines, you have torque from 1600-1800rpm), and overrev, even though in GTS you'll hit limiter is basically revving engine over it's red line (in real life damaging engine). And at the end, sweet spot of the engine shift is somewhere between power peak and 200-600rpm over it, but this also a lot depends on gearbox ratios, engine type, fuel type etc...

Short shifting is also used a lot for fuel economy in racing, you don't go to sweet spot to shift, but for example some 10% lower of it.

However in real life racing short shifting is usually, if for example engine revs up to 10k rpm, and sweet spot is at 8k rpm, short shift would be considered everything below 6.5k rpm...
Overrev would be considered everything above 10k rpm if ECU allows it (or engine alone)...

Cheers...

 

[vxr58]

In that Lewis Hamilton reference lap he said for some corners you want to short shift. I have never understood short shifting, I tried to google it a while back and all the advice I found was "short shifting is bad".

Clearly that's not the case?

The thing with that lap is that he was driving it as an F1 driver. That shows from his lines and his nervousness re curbs. Incredible he did that time whilst driving in real world mode...,anyway, I would suggest his tips re short shifting are more relevant to real life than the game. If you can be in the right gear and keep control then do it

 

[DriftMethod]

Every car is different since you have to factor in gearing. Here's a video:

Also, depends on situation as mentioned in posts above.

One other thing to consider is the time you waste shifting compared to staying in the same gear. Sometimes, you'll be near the end of a straight and should shift up, but then immediately have to brake and shift down, so might be faster to just run it up to rev limiter. Of course the opposite is also true, shifting down for a corner and having to quickly upshift again.

 

[Bruunz]

So i've been watching a few streams and noticing people say you need to shift early in a particular car. I decided to pay some attention to the power curves and the game and noticed something i dont think many people have spotted.
Your tacho flashes for gear change when peak power is reached. Not at the redline. You will notice that it flashes at different locations dependant on the car. Sometimes times 500rpm before redline or sometimes after redline which will match the power curve.

One thing to keep in mind is knowing how much power you would have in the gear versus staying in the previous gear. If the drop off past peak power isnt much it may be better to stay a bit longer in that gear instead of shifting if you would be making less power in the next gear.
e.g. 200hp @ 5000rpm, 225hp @ 5500rpm, 250hp @ 6000rpm, 240hp @ 6500hp
If the difference in gears is 1000rpm it would be better to hold out to 6500rpm and drop to 5500rpm vs 6k to 5k.

In regards to short shifting, i would say its primary purpose if for balancing the car and setup for a corner. Using the clutch and changing gears will change the balance of a car.
A good example is a turn over a crest. You have the turning action which is lateral force, the crest which is a vertical force and will make the car light on grip. Then changing gear which would be a z axis force both negative and positive (positive when disengaging drive then negative when engaging).
You would want to minimise the amount of movement whilst light on grip, so if you had a need to change gear whilst over the crest it would be better to short shift prior to the turn so you manage less forces being applied to the vehicle. This would also apply to off camber corners.

Here is a video of me with 2 examples of short shifting. The top of 2nd gear for me is @ 110km/h and the top of 3rd gear is @ 145km/h.

1) @30secs
I short shift into 3rd on the uphill esses and the last the corner is a left off camber corner with a crest. My car get very light coming across it and if stay in second it becomes too responsive and then i would have to shift during the downhill then quickly shift back into 2nd. Easier to shift into 3rd maintain speed and use the downhill to make up for the lack of power.

2) @55secs
Long left that is a little off camber. This is effectively a flat out corner for me however i shift before the apex to maintain balance at the apex and to setup for the next corner. I've tried staying in 3rd but i hit the rev limiter before the braking point.

 

[cleanLX]

Redline... so it works for the Z06 and the S2000... high performance motors, and in the case of the S2000 one built specifically to run at high rpm.
Red line on my 92 mustang 5.0 from the factory was 6250, made peak power at 4900rpm, but it ran hardest shifting at 5600/5400/5250 respectively for shifts into 2/3/4 (gear ratios, and maximizing power under the curve).
Redline on my 4.0 I6 Jeep was 5750... mmm... k... it fell off a cliff over at about 4500rpm.
The Hemi in my Grand Cherokee redlines at 6200... runs hardest shifted handy 5500.
These motors are very much full of TQ... not so much designed for HP.

It does indeed depend on a lot.
The current motor in my Mustang is built to handle 8500rpm(redline) makes peak power at 6300rpm, yet runs hardest at the track shifted at 7500rpm.
Blows every conventional rule out of the water right?... shift 1200rpm after peak, but 1000rpm prior redline...

Only way to know for sure is set up your own 1/4 "time trail" and see what takes place with each individual car, whilst taking in mind trans gear ratio differentials/shift recovery and logging...
In the real world, I make time for that with my Mustang...
In the game, I just shift on the limiter thanks.

 

[cleanLX]

btw... the video DriftMethod posted, do the math for the 1 - 2 shift on the S2000... bet it comes out to near 10,000 rpm.

 

[Bruunz]

Blows every conventional rule out of the water right?... shift 1200rpm after peak, but 1000rpm prior redline...

It's all about the power curve.

As mentioned previously, gearing is a major factor but too individual and specific to have a general discussion about.