Rear wheel steering?

[Lameboy]

Hi everyone, I've had this question since the release of the GT3RS, does this game support rear wheel steering? Like is it a real feature thats being implemented? I feel it in the 991 GT3RS and with the newly released 812 superfast as well, which is why I thought now would be a good time to ask. So is it all in my head or are my rear wheels actually helping me turn?

[kazereal]

In the cars that have rear wheel steering it is supported by AC, Nissan GT-R R34 for example has it.

[Mr Deap]

Originally posted by K&N Representative:

Hi everyone, I've had this question since the release of the GT3RS, does this game support rear wheel steering? Like is it a real feature thats being implemented? I feel it in the 991 GT3RS and with the newly released 812 superfast as well, which is why I thought now would be a good time to ask. So is it all in my head or are my rear wheels actually helping me turn?

To get faster lap, it goes against you. The rear wheel steering make the car a lot more predictable.

[Drisq Kivuli]

Originally posted by K&N Representative:

Hi everyone, I've had this question since the release of the GT3RS, does this game support rear wheel steering? Like is it a real feature thats being implemented? I feel it in the 991 GT3RS and with the newly released 812 superfast as well, which is why I thought now would be a good time to ask. So is it all in my head or are my rear wheels actually helping me turn?

It is actually implemented. During a replay hit F5 and zoom in on the rear wheel to see this in action.


From the official forums

quote:


The rear wheels steer in a more complex way than what the marketing buzz might make you believe.

Marketing: Rear wheels steer opposite to the front until 80km/h up to 3° angle. Steer in the same direction as the front from 80km/h and over, up to 2.6° angle

Reality: Rear wheels steer opposite up to 3° at very very low speeds to help the car U-Turn more. At higher "low speeds" (until 80kmh) they will steer in the opposite direction but less than 3°, depending on the g forces, steering wheel angle, yaw angle of the car, slip angle and ratio of front and rear wheels....

Over 80kmh they will steer in the same direction, again depending on steer wheel angle, yaw angle of the car, slip angle and ratio of both front and rear wheels...

Long story short. What they try to do: When you do important moves on your steering wheel, you create a yaw rotation acceleration. In a rear engine car this yaw rotation acceleration can easily be very fast and that can make the car oversteery and unstable. Usually you fix this with a very understeery setup. So stable in turn in, but understeery mid turn and exit... typical road 911 handling.

With 4WS you can have a more neutral setup. When you steer to enter a corner, the 4WS system will understand when the yaw acceleration is "too much" and instantly steer the rear wheels towards the same position. This has 3 effects.
- Raises the slip angle of the rear tyres, thus the rear end has lateral grip sooner than in normal situations and at similar rate as the front end.
- Making the car move lateraly instead of rotating, lowers the yaw acceleration creating stability...
- and finally but even more importantly, making the car "slower" to rotate, gives time to the driver to react and correct any instability situations.

Obviously, and here's the tricky thing, once the system understands that there is no "emergency" and the driver handles the situation, then they return to the "neutral" position to actual help the car rotate. Otherwise the car would move laterally instead of making the turn, giving the impression of a big understeer.

Two ways to see all of this in action.
a) drive around a circuit. Start a replay. Press F5, position the camera very close to the rear wheel, either behind the rear wheel but parallel to the body of the car longitudinally, or on top of it trying to be able to see slight movements of the wheel taking the wheelarches as reference point. Keep in mind that we're talking at most 2° of rotation so you need to pay attention. Best occasion is at the turn in or corrections.

b) open the SUSPENSIONS dev app and look at the rear bump steer graph go... BONKERS everytime you move the wheel :) (maybe check with a normal car too, to understand the difference between normal bump steer, and 4WS rear steering)

http://www.assettocorsa.net/forum/index.php?threads/911r-rear-wheel-steering.41064/#post-810024

[Drisq Kivuli]

2014 Porsche GT3 active rear steering demonstration

https://www.youtube.com/watch?v=GvQh2ue--0g