Rear Wheel Steering

[B61]

You can hear the very small stones (large grains really) kick up from the tires through the vents and along the doors at low speeds only.

I 2nd that.
Also, they comes under the front (frunk's) cover, through some small holes as well.

Sponsored

 

[4thPcar]

If anybody is unsure regarding rear wheel steering 3 months into new car and for me its a great option and for sure would recommend ticking box you won't regret it

I made a post several weeks ago titled "The Argument for RAS," and it became quite a heated argument indeed (those that elected not to spec it perhaps feeling the need to be defensive). Overall however the consensus seemed to be very positive and for me, its a total game changer because I am not used to so large a vehicle.

I believe the actual spec is "rear axle steering," hence RAS.

 

[Sidicks]

Gl


Wait, so what you’re telling me is that if you lift off mid corner, the car becomes unsettled and goes into oversteer?! Whoulda thunk it?

Please. RWS doesn’t make the car less stable. You honestly think that Porsche designed the GT3 platform and then engineered in a feature with no dynamic benefits but with massive liability issues?

Isn't RWS linked to steering wheel angle NOT throttle position?

 

[Ross]

Isn't RWS linked to steering wheel angle NOT throttle position?

Speed is pretty fundamental!
At low speed rear wheels turn in opposite direction to fronts
At high speed same direction.
Hence different handling characteristics.
Nothing fundamentally dangerous about it. Just different and probably a bit better if you know what you are doing.
Makes low speed manoeuvring a little easier.
The car is immaculate without it, handles sublimely and is totally manoeuvrable.
It is as much of a ‘must have’ as the ioniser.
Go ahead and knock yourself out with it if you have a spare £1600.

 

[WuffvonTrips]

Isn't RWS linked to steering wheel angle NOT throttle position?

Correct. I assumed that Archimedes' point was that lifting off mid-corner in any rear-power-biased car can induce oversteer, whether or not it has RAS. (As frequently demonstrated on the Silverstone EC skid pan ? )

 

[Sidicks]

Speed is pretty fundamental!
At low speed rear wheels turn in opposite direction to fronts
At high speed same direction.
Hence different handling characteristics.
Nothing fundamentally dangerous about it. Just different and probably a bit better if you know what you are doing.
Makes low speed manoeuvring a little easier.
The car is immaculate without it, handles sublimely and is totally manoeuvrable.
It is as much of a ‘must have’ as the ioniser.
Go ahead and knock yourself out with it if you have a spare £1600.

Speed and throttle position are not the same thing, which is the key point.

Arguably nothing is a ‘must have’, but it’s clear that a large majority would view the RAS as important, certainly much more so than numerous other options and certainly more than the ioniser.

 

[satchurator]

Isn't RWS linked to steering wheel angle NOT throttle position?

As I understand it, in a track situation or in spirited driving, with or without RAS, with all-wheel drive or rear-wheel drive, if you have throttle engaged while cornering 'at the limit', and then disengage the throttle, that will change the behavior of the car as it rotates through the arc of the turn. In a 911 that would tend to induce oversteer. A point raised earlier in the thread was the [opinion / hearsay / fact] (*delete as appropriate) that RAS makes this phenomenon more unpredictable in the 911 GT3.

Corrections and clarifications warmly welcomed, particularly by any former F1 engineers who can speak authoritatively on the subject!

 

[MissionE]

I’ve been having this debate on another chat recently. I hadn’t considered until the PEC. Now deliberating as would need to sacrifice on my chosen colour and some other extras like elec charger cover to keep me on budget.

You’re paying over $100,000 for a car, do you really need to sacrifice paint colors to play the margins that short?

 

[MissionE]

Better question: does it make the car feel any lighter and more agile?

 

[f1eng]

Isn't RWS linked to steering wheel angle NOT throttle position?

In the early purely mechanical systems some manufacturers used I believe so.

We did develop a system at Benetton with Michael Schumacher, which got banned before it raced (like lots of expensive developments only one team has like CVT) and we had loads of parameters we could use in the control algorithm with steering angle and speed just two of them. We had lateral G, yaw rate, steering rate and the oversteer/understeer parameter in the equation, probably others I have forgotten, and could adjust their co-efficients (including setting them to zero, of course). It is 30 years ago and the only thing which I remember was that whilst we could change the balance nothing we did gave a better lap time since it doesn't increase grip.
With a driver of Schumacher's ability he could drive around some imbalance.

FWIW it was on of the first options I ticked when I specced my CT 4S and it was fitted to the car I had a go in at PEC Silverstone yesterday which was superb but RWS was most noticable turning round at the end of the skid area.

I have (obviously) never driven with it switched off in the way we would, and I am sure Porsche do in development, when eveluating and testing the system.

 

[G7SUM]

You’re paying over $100,000 for a car, do you really need to sacrifice paint colors to play the margins that short?

This is on a salary sacrifice scheme where I’m governed by a maximum monthly cost. I have no control over this sadly.

 

[MissionE]

This is on a salary sacrifice scheme where I’m governed by a maximum monthly cost. I have no control over this sadly.

They say money’s just energy

 

[Browning]

This is on a salary sacrifice scheme where I’m governed by a maximum monthly cost. I have no control over this sadly.

Luck for some

 

[G7SUM]

Luck for some

Could be worse…..?

 

[Murph7355]

They say money’s just energy

Yup - life's crap without them ?

Sponsored