991 GT3 rear wheel steering

991 GT3 rear wheel steering

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Discussion

N24

1,113 posts

239 months

Wednesday 9th April 2014
quotequote all
mollytherocker said:
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.
How would say a Caterham 7 run by that rule? I've had three - all fairly lowly models but the greatest thing about them is that they FEEL fast without being all that fast.

I'd really have liked a GT3 with lower gearing plus an overdrive - gives me 0-100mph in say 4 to 6 secs, plus a quiet gear for motorways - a top speed of say 140-160mph is more than adequate. Allows for greater opportunity for 'fun' with less risk of gaol-time when fun is only attainable at 100mph+

isaldiri

18,599 posts

168 months

Wednesday 9th April 2014
quotequote all
Just wondering and perhaps it's a dumb question but nevermind...

Is the rws on the car a passive or active system? If it works on a passive system that is say simply a formula based on speed and steering angle, would have thought it wouldn't really be something that is a driver aid in the way traction control/e-diff are which would take away from the driver interaction with the car. If it's actively increasing or decreasing rear axle deflection as needed by the car's ECU based on what the sensors are telling it, that's different though.

ORD

18,120 posts

127 months

Wednesday 9th April 2014
quotequote all
0-100mph in 4 to 6 seconds? Are you nuts? That would involve putting a rocket on the roof. The Veyron takes 5 seconds and is utterly mad.

av185

18,514 posts

127 months

Wednesday 9th April 2014
quotequote all
ORD said:
0-100mph in 4 to 6 seconds? Are you nuts? That would involve putting a rocket on the roof. The Veyron takes 5 seconds and is utterly mad.
991 GT3 takes 7.1......yes

lowndes

807 posts

214 months

Wednesday 9th April 2014
quotequote all
For normal road use I quite like the rear wheel steer on the turbo S which I imagine is a similar system to the GT3. If there are maintenance problems I expect them to be covered by warranty while I own the car and thereafter will leave it to the subsequent owners to sort out.

First PCGB track day at Castle Combe tomorrow. So I’ll be in the 968CS.

Horses for courses I guess.

Kawasicki

13,091 posts

235 months

Wednesday 9th April 2014
quotequote all
It will give stability at speed, that's the whole point. It's up to you if you like that kind of thing or not. It is hard to engineer stability into rear engined cars, rear wheel steering really helps.

bashful

171 posts

230 months

Wednesday 9th April 2014
quotequote all
By the arguments above, the GT3 should absolutely not have power steering or assisted brakes, as both systems dilute the purity of the control experience and both have the potential to go wrong.

fioran0

Original Poster:

2,410 posts

172 months

Wednesday 9th April 2014
quotequote all
bashful said:
By the arguments above, the GT3 should absolutely not have power steering or assisted brakes, as both systems dilute the purity of the control experience and both have the potential to go wrong.
that is a straw man argument.

Edited by fioran0 on Wednesday 9th April 17:58

Pip1968

1,348 posts

204 months

Wednesday 9th April 2014
quotequote all
fioran0 said:
bashful said:
By the arguments above, the GT3 should absolutely not have power steering or assisted brakes, as both systems dilute the purity of the control experience and both have the potential to go wrong.
that is a straw man argument.

Edited by fioran0 on Wednesday 9th April 17:58
I agree. It is about drawing a line in the sand somewhere before they all become video machines with a seat. I want to feel the danger and get the satisfaction of getting it right on my own.

I wonder how it will effect dealing with oversteer with all aids off (can they be turned completely off or into track mode - ????) and the same with the aids on.

Pip

mollytherocker

14,366 posts

209 months

Wednesday 9th April 2014
quotequote all
N24 said:
mollytherocker said:
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.
How would say a Caterham 7 run by that rule? I've had three - all fairly lowly models but the greatest thing about them is that they FEEL fast without being all that fast.

I'd really have liked a GT3 with lower gearing plus an overdrive - gives me 0-100mph in say 4 to 6 secs, plus a quiet gear for motorways - a top speed of say 140-160mph is more than adequate. Allows for greater opportunity for 'fun' with less risk of gaol-time when fun is only attainable at 100mph+
A Caterham is an extreme example of 'potential to be fast'. The speed does not come easy, it takes skill, balance and effort to get one near its limits.

Steve Rance

5,446 posts

231 months

Wednesday 9th April 2014
quotequote all
911's used to be like that.

graemel

7,034 posts

217 months

Wednesday 9th April 2014
quotequote all
Many thanks for posting the video. It also looks to be adjusting the wheel base of the car at the same time. From the road test reports it makes the steering feel far more responsive and the car changes direction quicker. I suppose I should not knock it until I have tried it. It is the Porsche way of moving the game on. But what is the game. What is the goal. To create a car that can be driven by most people without a thought being given to the mechanical processes involved. We will make is PDK only so nobody has to worry about messing up the gear change. Sixth to third can't be done so you cannot buzz the engine. With the 991GT3 that seems to be the least of their worries.
I am not maligning the guys on here that have bought the new GT3 as we all like different things for different reasons. I'm sure it is an awesome weapon. But I am quite analytical. Much the same as I am certain Steve and Neil are and anyone out there with some real track day and race experience. Whilst in the car and out of the car at a race circuit you are constantly anaylising what is going on, what has gone on. What can you do or can be done to improve that lap time.
The new breed of sportscar whilst being very efficient with huge amounts of mechanical grip and trick electronics numb that experience and for me there is far less skill envolved. From a sports car perspective I am only interested in something that really focuses the mind. Much like the Ultima I'm sure. Something that makes you think about what you are doing, why you are doing it and how you can do it better. I do not want to own something that removes 50% of the decision making from you and half the adrenalin rush. The decision making is what gives you the buzz.




Harris_I

3,228 posts

259 months

Thursday 10th April 2014
quotequote all
Amen.

Let us mourn the passing of an era.


DiscoColin

3,328 posts

214 months

Thursday 10th April 2014
quotequote all
NBTBRV8 said:
It will be interesting to see if they cover this under extended warranty once the new car warranty runs out.
Depends on whether a lot of them start to fail probably. If it looks potentially common and expensive then they will probably just retrospectively reclassify it as a consumable like the hub flange/central bolt, nut, upright, bearing and locator pins on the 997..... (Currently just the flange, bearing and nut on the 991 are consumables at the moment). getmecoat

I will be very impressed indeed if this system does not end up prone to failure or given a short service life within the next 3-4 years...

Steve Rance

5,446 posts

231 months

Thursday 10th April 2014
quotequote all
I fear that the car is under developed. Any big GT car producing that kind of performance puts huge loads on itself which do not bode well for anything under developed.

FoR me GT3's were the ultimate 'old money' car in this respect. By that yardstick the 991 is very much 'new money'.. Only time - a long time - will tell..

tjlees

1,382 posts

237 months

Friday 11th April 2014
quotequote all
Harris_I said:
Amen.

Let us mourn the passing of an era.
Porsches have been developing and honing for 50 years. From a 2ltr air cooled 128hp to the screening 475hp 3.8ltr gt3. I'm looking forward to a 911 being mostly made of carbon with a kers system as standard and maybe active aero.

991 gt3 as a special daily road car and occasional trackday car, looks a very good choice. If I want the full blown race experience I'll go for the radical sr8 or rxc turbo - both can be road going as well with proper downforce. Even the 997.2 4.0 RS is not in the same league as these track weapons.

If I believe half of the reviews in the mags, the 991 gt3 brings you onto a new level of sensory gratification - different from previous gt3s but nevertheless similar. Some of the challenge may have gone through the Pdk and 4ws which I may have a problem with on the track but probably not the road, since I cannot take the racing line and uk road surfaces are too unpredictable to have full on commitment into a corner. I would be very happy to live with that comprise to have more of a useable car given the state of the weather, roads and traffic in the uk.

Use a 991 gt3 most of the time, hack round silverstone and go on my annual euro tour including the ring cloud9 ( without ending up deaf, my left leg bigger than my right and a knackered back!)


Harris_I

3,228 posts

259 months

Friday 11th April 2014
quotequote all
tjlees said:
Porsches have been developing and honing for 50 years. From a 2ltr air cooled 128hp to the screening 475hp 3.8ltr gt3. I'm looking forward to a 911 being mostly made of carbon with a kers system as standard and maybe active aero.
At which point it will only be exploitable and enjoyable on track.

tjlees said:
991 gt3 as a special daily road car and occasional trackday car, looks a very good choice. If I want the full blown race experience I'll go for the radical sr8 or rxc turbo - both can be road going as well with proper downforce. Even the 997.2 4.0 RS is not in the same league as these track weapons.
Some people prefer the tintop experience. A 996 or 7 Cup car is close to the road going version (the 6 especially so) and require a high degree of skill. For some, that is the most satisfying part of owning a GT3.

tjlees said:
If I believe half of the reviews in the mags, the 991 gt3 brings you onto a new level of sensory gratification - different from previous gt3s but nevertheless similar.
Journo reviews become less worthwhile the more specialist a car and the more skill it requires to extract a fast time. 911s traditionally needed a very particular skillset to extract a fast time. That is no longer the case. In which case the average buyer of a GT3 might also consider mid-engined alternatives like the 458 or 12C. Personally, I would not have considered these 2 manufacturers as direct rivals to a homologated 911 as their road cars bore little resemblance to their race cars. The 911 was absolutely unique. Now it is not.

tjlees said:
Some of the challenge may have gone through the Pdk and 4ws which I may have a problem with on the track but probably not the road, since I cannot take the racing line and uk road surfaces are too unpredictable to have full on commitment into a corner. I would be very happy to live with that comprise to have more of a useable car given the state of the weather, roads and traffic in the uk.
Congestion, camera vans, speed limits and road surfaces in the UK have conspired to rob us of driving pleasure. The only way to take that pleasure back is to drive cars with lower limits and greater sensory feedback. For this reason I cannot see myself owning a modern supercar ever again.

tjlees said:
Use a 991 gt3 most of the time, hack round silverstone and go on my annual euro tour including the ring cloud9 ( without ending up deaf, my left leg bigger than my right and a knackered back!)
Sounds fantastic. But Porsche chose to apply a racing tag to the car which doesn't race. The recent engine issues only highlight how even Porsche have succumbed to the value of a brand (think M-Sport). Maybe they should have called it a GTS.


tjlees

1,382 posts

237 months

Friday 11th April 2014
quotequote all
Harris_I said:
tjlees said:
Porsches have been developing and honing for 50 years. From a 2ltr air cooled 128hp to the screening 475hp 3.8ltr gt3. I'm looking forward to a 911 being mostly made of carbon with a kers system as standard and maybe active aero.
At which point it will only be exploitable and enjoyable on track.
I'm pretty sure the 997 GT3 is really only fully exploitable on the track given second is good for 90+ but I understand your point - for me once my cars starting heading north of 200bhp/tonne, tracks were the only answer, otherwise I was likely to start having scenery interface/police/other roaduser problems, regardless of my talent (lack of)

Harris_I said:
tjlees said:
991 gt3 as a special daily road car and occasional trackday car, looks a very good choice. If I want the full blown race experience I'll go for the radical sr8 or rxc turbo - both can be road going as well with proper downforce. Even the 997.2 4.0 RS is not in the same league as these track weapons.
Some people prefer the tintop experience. A 996 or 7 Cup car is close to the road going version (the 6 especially so) and require a high degree of skill. For some, that is the most satisfying part of owning a GT3.
The radical rxc is a tintop (grp) and apparently not an intimidating drive. I'm with you on the requiring skills to drive. When I nail the Ultima/Atom on the track (in my own mind but probably not the instructors!) it's a brilliant feeling. On the road though, i'm fighting frustration with bad roads, other roadusers, cold tyres, cold brakes and race suspension that can't really cope.

Harris_I said:
tjlees said:
If I believe half of the reviews in the mags, the 991 gt3 brings you onto a new level of sensory gratification - different from previous gt3s but nevertheless similar.
Journo reviews become less worthwhile the more specialist a car and the more skill it requires to extract a fast time. 911s traditionally needed a very particular skillset to extract a fast time. That is no longer the case. In which case the average buyer of a GT3 might also consider mid-engined alternatives like the 458 or 12C. Personally, I would not have considered these 2 manufacturers as direct rivals to a homologated 911 as their road cars bore little resemblance to their race cars. The 911 was absolutely unique. Now it is not.
Absolutely! As the 991 GT3 is now not race proven and has broadened its appeal, its racing characteristics have been diluted. I think people who liked thinly veiled race cars loved the 996/997 GT3/RS. However for me and probably others, when comparing 458, 12C and even the 991 Turbo, the 991 GT3 looks like a relatively good value, special and sensory overloaded daily driver.

Harris_I said:
tjlees said:
Some of the challenge may have gone through the Pdk and 4ws which I may have a problem with on the track but probably not the road, since I cannot take the racing line and uk road surfaces are too unpredictable to have full on commitment into a corner. I would be very happy to live with that comprise to have more of a useable car given the state of the weather, roads and traffic in the uk.
Congestion, camera vans, speed limits and road surfaces in the UK have conspired to rob us of driving pleasure. The only way to take that pleasure back is to drive cars with lower limits and greater sensory feedback. For this reason I cannot see myself owning a modern supercar ever again.
There are some roads that you can still tickle all the senses to get the required emotions going. Even in a flappy paddled 4wd lambo, I managed have a great hoon at legalish speeds. Not the last in feel and handling but very enjoyable on uk roads.

Harris_I said:
tjlees said:
Use a 991 gt3 most of the time, hack round silverstone and go on my annual euro tour including the ring cloud9 ( without ending up deaf, my left leg bigger than my right and a knackered back!)
Sounds fantastic. But Porsche chose to apply a racing tag to the car which doesn't race. The recent engine issues only highlight how even Porsche have succumbed to the value of a brand (think M-Sport). Maybe they should have called it a GTS.
For some I think this is the biggest problem with the 991 GT3, its not race proven, it has reliability issues and it is effectively blurring the lines between the GTS and Turbo. For me, I can now get a Porsche that is special daily that IMHO looks wonderful and sounds unbelievable with apparently outstanding/confidence inducing handling, ride and performance especially on uk roads.

IREvans

1,126 posts

122 months

Friday 11th April 2014
quotequote all
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.
The rubber or urethane bushes on the RWS arms will be durability rated to around 100k miles, or rather less if used on track. The bush (or probably the whole arm) can then be changed. A rose joint on road car suspension isn't really suitable as the lifetime is low (we change them on rallycars after around 750 competitive miles), and they offer no compliance, so lots of vibration is transferred into the cabin.

I have a 991 GT3, and have done around 2500 miles in it. You don't notice the RWS at all, but appreciate the car is very nimble bearing in mind its size. This became more apparent when I jumped into a 991 C2S loan car.....driving it on the same roads around here, it feels noticeably less nimble, but having said that there's obviously lots of other detail differences which affect the dynamics, not just RWS..!

Kawasicki

13,091 posts

235 months

Saturday 12th April 2014
quotequote all
graemel said:
Many thanks for posting the video. It also looks to be adjusting the wheel base of the car at the same time. From the road test reports it makes the steering feel far more responsive and the car changes direction quicker. I suppose I should not knock it until I have tried it. It is the Porsche way of moving the game on. But what is the game. What is the goal. To create a car that can be driven by most people without a thought being given to the mechanical processes involved. We will make is PDK only so nobody has to worry about messing up the gear change. Sixth to third can't be done so you cannot buzz the engine. With the 991GT3 that seems to be the least of their worries.
I am not maligning the guys on here that have bought the new GT3 as we all like different things for different reasons. I'm sure it is an awesome weapon. But I am quite analytical. Much the same as I am certain Steve and Neil are and anyone out there with some real track day and race experience. Whilst in the car and out of the car at a race circuit you are constantly anaylising what is going on, what has gone on. What can you do or can be done to improve that lap time.
The new breed of sportscar whilst being very efficient with huge amounts of mechanical grip and trick electronics numb that experience and for me there is far less skill envolved. From a sports car perspective I am only interested in something that really focuses the mind. Much like the Ultima I'm sure. Something that makes you think about what you are doing, why you are doing it and how you can do it better. I do not want to own something that removes 50% of the decision making from you and half the adrenalin rush. The decision making is what gives you the buzz.





No wheelbase adjustment. It gives agility at low speeeds by giving additional yaw to counter the lower response of a tyre(tyre response is connected to road speed), and it reduces yaw at speed..you don't have to wait for the body of the car to move to a big slip angle...which gives stability.

Edited by Kawasicki on Saturday 12th April 09:23