GT3 RS weaving at high speed
Discussion
Two things:
1. It's following cambers like a an absolute b*stard at high speeds. It's bloody scary because one minute it's tracking straight and the next your driving towards the barrier or into another lane (and the steering is still straight) - and the result is that your hands are hurting from holding wheel so tight...
2. Related to 1. On the brakes, hard, from high speed, the rear stays planted but the front once again is all over the place and you have to steer "actively" to keep it in a straight line.
My MK2 GT3 didn't do this.
Any fixes? I'm not convinced about the SSRs it's wearing either, they give the car a vibration until they've warmed up (pressures?). Car is running factory suspension settings. I'm considering softening the anti roll bars until the trackday season starts again in earnest next year....
1. It's following cambers like a an absolute b*stard at high speeds. It's bloody scary because one minute it's tracking straight and the next your driving towards the barrier or into another lane (and the steering is still straight) - and the result is that your hands are hurting from holding wheel so tight...
2. Related to 1. On the brakes, hard, from high speed, the rear stays planted but the front once again is all over the place and you have to steer "actively" to keep it in a straight line.
My MK2 GT3 didn't do this.
Any fixes? I'm not convinced about the SSRs it's wearing either, they give the car a vibration until they've warmed up (pressures?). Car is running factory suspension settings. I'm considering softening the anti roll bars until the trackday season starts again in earnest next year....
Cheers Glenn,
To be fair, it only does it when the road surface starts to deteriorate but I'm going to get those tyre pressure checked nonethless. Porsche reverted the suspension settings to stock before I bought it and checked it out and gave it a clean bill of health so I don't think it's a hardware problem. Have to get it up on the ramp and check it out.
I've caught the tyres on the front arches a fews time too... bloody hell. Still wish you could get RS's in speed yellow!
To be fair, it only does it when the road surface starts to deteriorate but I'm going to get those tyre pressure checked nonethless. Porsche reverted the suspension settings to stock before I bought it and checked it out and gave it a clean bill of health so I don't think it's a hardware problem. Have to get it up on the ramp and check it out.
I've caught the tyres on the front arches a fews time too... bloody hell. Still wish you could get RS's in speed yellow!
Although my car is a bog standard C2 i had the same bollox,everything you are experiencing is what i went through.
In the end it came down to the tyres the side walls on p-zerro rosso were just too soft causing that shit-yourself feeling at high speed.
I sold them and put pilot sport N1s on recomendation from simon at redline racing and the problem improved 95%
Imho i think you are right,i spent alot of time and money and listened to a lot of people who i should'nt have.
I always believed it was the tyers and i was right,these cars are very tyre sensitive and i can imagine your car will be even more so.
>> Edited by rob05 on Sunday 13th November 12:35
In the end it came down to the tyres the side walls on p-zerro rosso were just too soft causing that shit-yourself feeling at high speed.
I sold them and put pilot sport N1s on recomendation from simon at redline racing and the problem improved 95%
Imho i think you are right,i spent alot of time and money and listened to a lot of people who i should'nt have.
I always believed it was the tyers and i was right,these cars are very tyre sensitive and i can imagine your car will be even more so.
>> Edited by rob05 on Sunday 13th November 12:35
This is on the road right?
I had this problem too and its down to driving technique - I was corrected by the instructor from cadence (Dave) so I suggest you do half a day with him. In brief however, you are holding the wheel too tight. Don't hook your thumbs over, rest them on the little stick out pads of the wheel and keep your grip fairly relaxed. Then when the wheel moves, don't fight it or try to dampen it too much as that just forces the car off line as you can never quite keep up with what the wheels doing.
It makes a world of difference. There are also things you need to do not be knocked off line on corners in the road (although it does lead to a bit of understeer as basically you get the weight off the front), but you would probably do yourself more good having a lesson with Dave. I had EXACTLY the same issues as you when I got my RS and I thought maybe I'd made a mistake. Now I know how to work with it rather than trying to force it its lovely and less demanding & draining on the road. Anyway with any luck you have the same issue I did, which means you can cure it
Tyre pressures should be 32f 38r if I remember (its under the fuel cap). Not sure about this vibration though when cold though - seems odd.
I've had my car setup for road/track usage by JZM. More balance on track won't make it any nicer on the road though, so I'd leave that alone until you are happy + confident with the car. I really did get thrown a foot out of the lane I was in sometimes before I relaxed my grip. Not any more...
I wrote a review of cadence training here : www.pistonheads.co.uk/gassing/topic.asp?t=217694
>> Edited by DanH on Sunday 13th November 14:59
I had this problem too and its down to driving technique - I was corrected by the instructor from cadence (Dave) so I suggest you do half a day with him. In brief however, you are holding the wheel too tight. Don't hook your thumbs over, rest them on the little stick out pads of the wheel and keep your grip fairly relaxed. Then when the wheel moves, don't fight it or try to dampen it too much as that just forces the car off line as you can never quite keep up with what the wheels doing.
It makes a world of difference. There are also things you need to do not be knocked off line on corners in the road (although it does lead to a bit of understeer as basically you get the weight off the front), but you would probably do yourself more good having a lesson with Dave. I had EXACTLY the same issues as you when I got my RS and I thought maybe I'd made a mistake. Now I know how to work with it rather than trying to force it its lovely and less demanding & draining on the road. Anyway with any luck you have the same issue I did, which means you can cure it
Tyre pressures should be 32f 38r if I remember (its under the fuel cap). Not sure about this vibration though when cold though - seems odd.
I've had my car setup for road/track usage by JZM. More balance on track won't make it any nicer on the road though, so I'd leave that alone until you are happy + confident with the car. I really did get thrown a foot out of the lane I was in sometimes before I relaxed my grip. Not any more...
I wrote a review of cadence training here : www.pistonheads.co.uk/gassing/topic.asp?t=217694
>> Edited by DanH on Sunday 13th November 14:59
Murcielago_Boy said:
Cheers Glenn,
Porsche reverted the suspension settings to stock before I bought it and checked it out and gave it a clean bill of health so I don't think it's a hardware problem.
Therein probably lies your answer !! Get it set up for fast road? track? by someone who knows what they're doing such as JZM or Parr....
DanH said:
This is on the road right?
I had this problem too and its down to driving technique - I was corrected by the instructor from cadence (Dave) so I suggest you do half a day with him. In brief however, you are holding the wheel too tight.
>> Edited by DanH on Sunday 13th November 12:36
I made exactly this mistake too. Relaxing your grip and arms in general makes a big difference...
gfreeman said:
Cheers Glenn,
Porsche reverted the suspension settings to stock before I bought it and checked it out and gave it a clean bill of health so I don't think it's a hardware problem.
Therein probably lies your answer !! Get it set up for fast road? track? by someone who knows what they're doing such as JZM or Parr....
Agreed. This is a must if you want to be sure it is all pointing in the right direction. A mild track set up on my (old) RS made it better on the road as well.
Some of what Dan says about relaxing yr grip also helps the steering to deal with sudden camber changes on the road. Remember the RS chassis is very stiff and optimised for fast track work. It does not like undulating cambered country B roads.
Have fun. Jonathan
I changed tyres on my 1992 964RS and it totally changed the car....for the worst...and the symptoms were identical to those that you are experiencing. A friend has had a similar experience with a 911 SC.
Are the tyres on your car original fit? "N" numbers and all? I had geometry checked, dampers, etc etc but it didn't ever get back to how it was before. Conclusion was that the sidewall construction was to blame - I think someone else has mentioned how a less stiff sidewall affects the car.
Are the tyres on your car original fit? "N" numbers and all? I had geometry checked, dampers, etc etc but it didn't ever get back to how it was before. Conclusion was that the sidewall construction was to blame - I think someone else has mentioned how a less stiff sidewall affects the car.
seandudding said:
The rear end problem under braking is well documented, it is down to the rear ride height.
Also I would not trust and OPC to do the set up, I would go to JZM or Parr and get a good setup put on the car, the transformation is fantastic.
Doesn't sound like thats the problem hes getting - he was complaining about the front tracking cambers under hard braking. I'm pretty sure thats just the way it is, although again a relaxed grip on the wheel makes everything better.
i think I can comment on this better than most
Ive done a total of 29,500 miles in the 2 RSs
my track GT3 RS which runs on michelin cup tyres
with huge amount of camber is a nightmare on the motorways
especially in the slow lane and on British roads
once you get to the continent the handling of the car changes dramatically
I have just got back from the nurburgring and the journey to and from Germany
was fine even in the rain - a bit bumpy in Belgium
My other GT3 RS is a standard road car and handles superbly - I was told that
if you run the car mainly on the road use the standard Pirellis ( not the type Rs )
and check you tyre temps hot and cold
In Germany ive seen 197 and 195 from both and believe me they are a staedy as a rock at those speeds
the car is awesome on the road and will beat most cars - excluding a Carrera GT
dont hold the steering wheel tight !
tim
Ive done a total of 29,500 miles in the 2 RSs
my track GT3 RS which runs on michelin cup tyres
with huge amount of camber is a nightmare on the motorways
especially in the slow lane and on British roads
once you get to the continent the handling of the car changes dramatically
I have just got back from the nurburgring and the journey to and from Germany
was fine even in the rain - a bit bumpy in Belgium
My other GT3 RS is a standard road car and handles superbly - I was told that
if you run the car mainly on the road use the standard Pirellis ( not the type Rs )
and check you tyre temps hot and cold
In Germany ive seen 197 and 195 from both and believe me they are a staedy as a rock at those speeds
the car is awesome on the road and will beat most cars - excluding a Carrera GT
dont hold the steering wheel tight !
tim
Just to make the situation clearer.
We're talking about UK motorways here. The car feels perfectly "aerodynamically" stable at high speed, particaluarly the rear end. In fact, most of the time the car feels perfect.
However it's just when there are reasonable cambers in the outside lane, I'll be going straight and all of a sudden I can "feel" the car "riding the camber" within the lane and it will pull deliberately to either the left or the right and when you're going QUICK (I'm NOT talking 80mph here it's a touch more than that.... ) it's extremely fatiguing and shit-yourself-inducing behaviour.
To elaborate a bit further, my MK2 didn't have the same propensity for this behaviour but then I did NOT drive it so quickly either so perhaps the comparison is unfair. The RS has a TOTALLY sorted front end - the "flapping" tendency of the MK2 is completely gone so it requires less hard work at high speed which means on a deserted motorway, you don't hang about. BUT when there's a camber on the road it moves around quite a bit.
In response to this, I've found myself gripping the steering wheel like a vice and sitting there trying to react to where the front wheels are going. I suspect that my car is behaving like every other RS out there and it's sorted but I don't understand how relaxing at the wheel will solve the problem....
Also, related to this, under pretty heavy braking from high speed, I *think* the weight transfer to the front wheels exagerrates the camber-following problem causing a slight weaving tendency which also results in brown-trouser syndrome.
The standard fit tyres should be P-Zero Corsas but it's got Dunlop SSRs on it. John, I didn't buy it from an OPC.
I would really like to know what the stock suspension setup from Porsche is? 60% road and 40% track or vice versa etc...
Because until the weather breaks, I'll probably soften the whole car up and then send it back for more suspension aggression come spring next year.
We're talking about UK motorways here. The car feels perfectly "aerodynamically" stable at high speed, particaluarly the rear end. In fact, most of the time the car feels perfect.
However it's just when there are reasonable cambers in the outside lane, I'll be going straight and all of a sudden I can "feel" the car "riding the camber" within the lane and it will pull deliberately to either the left or the right and when you're going QUICK (I'm NOT talking 80mph here it's a touch more than that....
) it's extremely fatiguing and shit-yourself-inducing behaviour. To elaborate a bit further, my MK2 didn't have the same propensity for this behaviour but then I did NOT drive it so quickly either so perhaps the comparison is unfair. The RS has a TOTALLY sorted front end - the "flapping" tendency of the MK2 is completely gone so it requires less hard work at high speed which means on a deserted motorway, you don't hang about. BUT when there's a camber on the road it moves around quite a bit.
In response to this, I've found myself gripping the steering wheel like a vice and sitting there trying to react to where the front wheels are going. I suspect that my car is behaving like every other RS out there and it's sorted but I don't understand how relaxing at the wheel will solve the problem....
Also, related to this, under pretty heavy braking from high speed, I *think* the weight transfer to the front wheels exagerrates the camber-following problem causing a slight weaving tendency which also results in brown-trouser syndrome.
The standard fit tyres should be P-Zero Corsas but it's got Dunlop SSRs on it. John, I didn't buy it from an OPC.
I would really like to know what the stock suspension setup from Porsche is? 60% road and 40% track or vice versa etc...
Because until the weather breaks, I'll probably soften the whole car up and then send it back for more suspension aggression come spring next year.
murceilago boy,
It sounds like your car has had a lot of camber dialled in as my bog standard RS
is not like that - maybe the person who owned it before had a track
set up on the car - look at the front wheels from above the front wing
my road RS rides like a limo !
Maybe its the tyres
tim
It sounds like your car has had a lot of camber dialled in as my bog standard RS
is not like that - maybe the person who owned it before had a track
set up on the car - look at the front wheels from above the front wing
my road RS rides like a limo !
Maybe its the tyres
tim
Relaxing your grip helps because the steering deflects when it needs to, but then corrects just as quickly without really deviating your course. If you have a vice like grip it will have a tendency to prolong the deflection period making you actually turn off course. It then becomes a viscious circle as you tense up more and the problem gets worse.
I tend to get it on country roads when making progress, although it happens a bit on crap bits of motorway (mostly the inside lane). Relaxing on the wheel sorted it for me, and I have a JZM road/track geo.
Of course it could be too much camber, but theres a reasonable chance its the grip thing. Unhook your thumbs and try it then let us know?
I still reckon you'd enjoy a morning with the chap from cadence. It transformed my RS from being awfully hard work on the road, to being fine without any mods to the car...
Softening the car shouldn't make any difference. Your issue is not with body roll but geometry and spring rate. Get a geometry check done on the car. The RS doesn't run toe in which helps prevent wandering but at the expense of steering feel and speed of direction change. I have driven the RS in lots of different set ups and they all wander on camber changes I'm used to it now so it isn't a problem to me because its pretty predictable. The braking problem is due to a fairly soft spring rate that causes the front of the car to squat under heavy braking making the rear light and fish tail on uneven surfaces. It is actually the rear of the car that you are fighting and not the front. I have always had an issue with the springs on the RS. In my optnion the spring rate is too soft for a car marketted as a road/track car.
Steve R
Steve R
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