991 GT3 rear wheel steering

[fioran0]

Many of you may have seen this video already buts its of the RWS working on the 991 GT3. Picture of the setup is also shown.



(Credit to Elephant Racing for both pic and video). Interesting to hear the thoughts people have after watching it work. Polarizing issue, likely to be more so after the video but ..........
http://www.youtube.com/watch?v=GvQh2ue

[Trev450]

Link is not working Neil.

[993AL]

Trev450 said:

Link is not working Neil.

I think this is it. http://www.youtube.com/watch?v=GvQh2ue--0g

[LordGrover]

...at 50-80kph is it fixed?

[Trev450]

993AL said:

Trev450 said:

Link is not working Neil.

I think this is it. http://www.youtube.com/watch?v=GvQh2ue--0g

Thanks.

[mrdemon]

great when new, not nice when it starts to get play and the cars are 2nd hand,

[Trev450]

Showing my limited technical knowledge here, but carrying on from mrdemon's post, the suspension components that pivot when the rws is operating appear to be bushed as opposed to having a ball joint or rose joint. Surely this is likely to accelerate wear to these bushes.

[993AL]

Trev450 said:

Showing my limited technical knowledge here, but carrying on from mrdemon's post, the suspension components that pivot when the rws is operating appear to be bushed as opposed to having a ball joint or rose joint. Surely this is likely to accelerate wear to these bushes.

Agreed, not the best engineered solution.

I read elsewhere that the actuator is a toothed belt affair which would suggest a driven nut and a screw as the actuator. I'm not suggesting that there will be failures but if there are they will fail in position. At the max 1.5 degrees on one hub I would think it will make for some interesting driving. I'm not trying to be a doom monger, just thinking about it technically.

[GT Glee]

My first thought is fail-over position; if they are leadscrew actuated then is likely wherever they were at the point of failure. The advantage is that it can hold at full load, the disadvantage is if it occurs with high steering angle (of course).

More steering angle and articulation than I imagined there would be, however, this makes me wonder about longevity and ability to hold geometry. Steering system for MOT purposes includes RWS and there are a significant number of tests carried out these days. And if the leadscrew wears (typically prone to this) this would show up as play.

RWS has been around for a long time so would make sense to compare with other systems to see if they to work well with time & miles, and are not a maintenance / MOT burden.

[NBTBRV8]

It will be interesting to see if they cover this under extended warranty once the new car warranty runs out.

[fioran0]

993AL said:

I think this is it. http://www.youtube.com/watch?v=GvQh2ue--0g

Thanks for fixing the link

[993AL]

fioran0 said:

993AL said:

I think this is it. http://www.youtube.com/watch?v=GvQh2ue--0g

Thanks for fixing the link

[fioran0]

I will lay my cards out and say that I am not a fan of this stuff at all. I don't think it has any place on a GT3 type car but each to their own. Im not about to take on a Don Quixote position. No one is forcing anyone to like it or buy it and there are always alternatives (including in this case just removing the unit and putting a straight control arm back in.....aftermarket anyone?). If its for you great, if not no sweat.

I often think that driving aids/systems don't exist for most people beyond the acronym. You don't tend to experience them physically from the driving seat so they don't take on a physical form. As such, it was interesting to see it doing its stuff in that video. Its real and it does something.

My own view can be summarised as, why would you want something like that on your sports car and how could you have any satisfaction as a driver with that going on at the back?

Anyone who has ever been behind a GTR and watched it automatically add yaw control 5 times as it goes round a corner will get the second part of that I am sure. The first part contains a long list of questions that I won't bore the forum with.

I wonder having watched that video if we are at another junction in time when those making technology fail get the human element to existence and experience.

I also wonder what anyone looking at a 991 GT3 and seeing that video will think. indifference, hesitancy, thumbs up?

Edited by fioran0 on Tuesday 8th April 12:27

[Trev450]

Shooting from the hip here, but I'm with Neil (Fioran0)on this. The GT3 should embody the very essence of chassis feedback and that should translate to the seat of the pants of the driver, and not be masked by driver aids.

In my opinion, RWS can be categorised in much the same manner as PDK (yes here we go again). It is another layer between the interaction of car and driver. And before the shouts of "its what the market demands" are repeated, the fact that it has not been offered as an option in the same way that PDK hasn't, suggests to me that Porsche are no longer interested in the enthusiast, but the wider market as a whole. That being the case, then the 991 GT3 can no longer be seen to be giving the driver a true visceral experience from behind the wheel.

If I wanted to be molly coddled by driver aids I would buy a GTR and pocket the £20+k difference.

Edited by Trev450 on Tuesday 8th April 15:00

Edited by Trev450 on Tuesday 8th April 15:03

[tjlees]

I have not driven the 991 gt3 yet, so I can't really comment, other reputable mags have given it game changer status so the gt3 must be successfully playing on the senses to get out the required pistonhead emotions.

I've just been out in my ultima with g96 porsche manual gearbox, no power steering, no abs and cold cut slicks. It's was a complete fking handful and I'd forgotten how easily it power slides I.e. Want to swap ends on cold tyres.

However once I'd got over the lack of Pdk, electric steering and psm, I had a right old hoon, getting right back into toe and heeling compete with a dab of opposite lock on powering out of the corners.

So unless I'm on the ring or in a race I personally don't need 4 wheel anything nor a milli sec gear change - I have enough sensory overload and fun handling cars without it.

For mainly a road going car, I'm still not sure how 4ws adds to the enjoyment other more confidence going into high speed corners maybe? Pdk on the road with a fast and high revving engine is probably a good idea. Electric steering saves fuel.

Would 4ws, electric steering, Pdk and gt3 weight put me off buying one for the road? No. The gt3 is now more useable more of the time and manages to thrill, according to the reviewers, to same level but in a different way. For me the 991 gt3 as package is coming close to being a very special daily.

[Trev450]

tjlees said:

For me the 991 gt3 as package is coming close to being a very special daily.

And therein lies the problem imo. Surely the Carrera and Turbo very adequately meet this criteria. The GT3 on the other hand was always the more track-focused offering but could be used on the road as well.

Love the sound of your Ultima by the way.

[N24]

Trev450 said:

Shooting from the hip here, but I'm with Neil (Fioran0)on this. The GT3 should embody the very essence of chassis feedback and that should translate to the seat of the pants of the driver, and not be masked by driver aids.

In my opinion, RWS can be categorised in much the same manner as PDK (yes here we go again). It is another layer between the interaction of car and driver. And before the shouts of "its what the market demands" are repeated, the fact that it has not been offered as an option in the same way that PDK hasn't, suggests to me that Porsche are no longer interested in the enthusiast, but the wider market as a whole. That being the case, then the 991 GT3 can no longer be seen to be giving the driver a true visceral experience from behind the wheel.

If I wanted to be molly coddled by driver aids I would buy a GTR and pocket the £20+k difference.

Edited by Trev450 on Tuesday 8th April 15:00

Edited by Trev450 on Tuesday 8th April 15:03

I'd agree with this to some extent - however if one wants a new GT3 then it's this or nothing - and speaking as someone who bought one, the GTR never figured on the list of cars that were considered & I think that's true of pretty much every GT3 buyer.

[Steve Rance]

You don't need an EDiff or rear wheel steer to rotate a car. It's a skill that can be learned and a rewarding one to get right. I'd prefer a car that rewarded the skill rather than thinking for me and excluding me from the process. On saying that, if you have no wish to learn it and enjoy travelling at the maximum speed with the minimum effort - nothing wrong with that - then I suppose it would be a good thing! Not for me though

[tjlees]

Trev450 said:

And therein lies the problem imo. Surely the Carrera and Turbo very adequately meet this criteria. The GT3 on the other hand was always the more track-focused offering but could be used on the road as well.

Love the sound of your Ultima by the way.

When I drove the 991 Carrera IMHO it was a game changer with Pdk and even the electric steering. I couldn't get over its useable performance, ride and handling.

The 991 turbo will be something else. Maybe too fast, but still practical. I'm putting a roofbox on my 997.2, loading it up with the family (yes two teenage daughters do fit in the back) and heading towards the southwest coast this summer. I just have to control my right foot in the pyrenees

The ultima is great for getting back to basics with a 7ltr V8 and 600+lb/ft, but even more extreme than a RS, so has to be trailered everywhere unless I want to arrive deaf with a knackered back and all my holiday money spent on super unleaded.

[mollytherocker]

Some interesting and valid arguments.

The question I see is, should a car be automatically fast or provide the potential to be fast.

Thats it for me.