997.1 RS slow speed, straight damp road, lost control, why? - Page 5 - 911/Carrera GT - PistonHeads UK

Lost control in the RS on a straight damp road at 70 mph. very disappointing. Was driving very normally in middle lane following traffic, was checking the mirrors as car approaching fast in fast lane, felt the car twitch, when I looked up it was pointing right 25 degrees or so, overcorrection spinout results in me crossing all 3 lanes of the motorway, some light damage. but very dangerous! It felt almost like the car just suddenly lost control, I did nothing to warrant this reaction, was not driving fast, did not see any standing water, did not touch the white line, was not accelerating. It just lost control. So was chatting to a friend who said that he has heard about this, that the diff is aggressive, more so than the road car and less so than the track car, and when this aggressiveness kicks in, for example if I went over something slick on the road with the right hand rear tyre, that the resulting aggressive torque application on the left rear tyre gives the car a turning moment to the right, contributing to the spinout. Has anyone come across this? if so I would like to discuss, I now feel that I should not be going over 60mph on a damp and certainly not wet road in this car! fair enough, but I need to get to grips with why this car lost control so it doesn't happen again. p

Posh868 said: Lost control in the RS on a straight damp road at 70 mph. very disappointing. Was driving very normally in middle lane following traffic, was checking the mirrors as car approaching fast in fast lane, felt the car twitch, when I looked up it was pointing right 25 degrees or so, overcorrection spinout results in me crossing all 3 lanes of the motorway, some light damage. but very dangerous! It felt almost like the car just suddenly lost control, I did nothing to warrant this reaction, was not driving fast, did not see any standing water, did not touch the white line, was not accelerating. It just lost control. So was chatting to a friend who said that he has heard about this, that the diff is aggressive, more so than the road car and less so than the track car, and when this aggressiveness kicks in, for example if I went over something slick on the road with the right hand rear tyre, that the resulting aggressive torque application on the left rear tyre gives the car a turning moment to the right, contributing to the spinout. Has anyone come across this? if so I would like to discuss, I now feel that I should not be going over 60mph on a damp and certainly not wet road in this car! fair enough, but I need to get to grips with why this car lost control so it doesn't happen again. p What tyres are you running and are you sure your geo is correct?

I had a similar issue with my 997.1 GT3 on the M4 but this was purely down to cup tyres, wet road and an incorrect geo

Does not sound right to me. Get the geometry of the car checked. There was someone on here with a Boxster or Cayman (I can't remember) who recently reported a similar problem. It turns out that the toe in / toe out of his steering geometry was set 4 deg. (the correct setting) but in the WRONG direction. Even though this sounds like a long shot you have to check the geo in case there is a massive screw up here. You would have grounds for compensation if the car was set up incorrectly. Sorry to hear this. I am glad that nobody was hurt.

Thanks for the prompt responses! The accident happened in January between some of those showers we had, so granted tyres were cold, road was damp to wet, it wasn't raining. The tyres are Michelin Pilot Sport PS2 N2's all round, tread was good although a bit low in the back, 3mm before illegal. I still have them as replaced the tyres afterwards. The car had been to a MOT, and large service with Porsche about 1000 miles before. The geometry was setup by Porsche Reading 1 year before that, no bumps or mishaps since then, so assuming it was ok. Really wanted to investigate the 'Differential Aggressiveness' thought though as my bud, who has also had a GT3 RS, has specifically heard that this has caused crashes almost exactly like this, at slower speeds, sometimes as slow as 60mph, as described in the past. You have not heard of this?

Posh868 said: Thanks for the prompt responses! The accident happened in January between some of those showers we had, so granted tyres were cold, road was damp to wet, it wasn't raining. The tyres are Michelin Pilot Sport PS2 N2's all round, tread was good although a bit low in the back, 3mm before illegal. I still have them as replaced the tyres afterwards. The car had been to a MOT, and large service with Porsche about 1000 miles before. The geometry was setup by Porsche Reading 1 year before that, no bumps or mishaps since then, so assuming it was ok. Really wanted to investigate the 'Differential Aggressiveness' thought though as my bud, who has also had a GT3 RS, has specifically heard that this has caused crashes almost exactly like this, at slower speeds, sometimes as slow as 60mph, as described in the past. You have not heard of this? I can honestly say that I have NEVER heard of the 997 GT3 diff being described as 'aggressive'! 'Open' and 'like chocolate' - YES

I would also say that your event is more likely to be the result of standing water and/or naff geo. Without a change in torque/speed, I'd doubt even a faulty diff would send you into a spin.

V8KSN said: I had a similar issue with my 997.1 GT3 on the M4 but this was purely down to cup tyres, wet road and an incorrect geo and no driver error whatsoever! lol

Its a surprise you weren't on Cups , thats exactly the symptoms of an aquaplaning GT3 on those tyres. The diff is aggresive by road car standards but you need to be doing far far more to it than you imply to get that sort of reaction. I had a straight line spin in my 996.2 GT3 but that was down to a very inadvisable up change from 2nd to 3rd at near max revs with some spinning of the rear wheels going on. Edited by Dblue on Tuesday 15th April 17:49

Dblue said: Its a surprise you weren't on Cups , thats exactly the symptoms of an aquaplaning GT3 on those tyres. The diff is aggresive by road car standards but you need to be doing far far more to it than you imply to get that sort of reaction. I had a straight line spin in my 996.2 GT3 but that was down to a very inadvisable up change from 2nd to 3rd at near max revs with some spinning of the rear wheels going on. Edited by Dblue on Tuesday 15th April 17:49 Agreed. Never had that unexpected experience on a number of 996 type GT3/RS cars. I have had the straight line moment when accelerating hard in third gear on a cold March day in the damp with low tread tyres...naturally the rears started to spin and car beginning to point in a different direction. Fortunately, managed to bring it back under control and nothing serious happended and I learned to change the tyres and not do that again!

Slickhillsy said: V8KSN said: I had a similar issue with my 997.1 GT3 on the M4 but this was purely down to cup tyres, wet road and an incorrect geo and no driver error whatsoever! lol

Even with new tires on my Porsches I slow down on damp roads. The tires do not play well with water on the road. And if it is cool, cold, you are just asking for trouble. 3mm tread depth is not worn out by the legal definition but I know from experience tires worn down to this point are slippery on damp roads like would not believe. Alignment, aka geo, is probably not a contributing factor though bad geo can result in uneven tire wear. Then what you have is are tires that are half good, half no good, if the wear is uneven across the rear tread faces, which is a good sign the geo is bad. When you replace the tires have the car treated to a proper geo to be sure you and the new tires start out right

It probably won't be the diff. That only locks under hard braking or acceleration. If you weren't pushing and you were on sports it's unlikely it's your geo unless the car is pretty much undrivable everywhere. More likely to be a pack of oil or Diesil on the road ie something external. I'd get your geo checked as a matter or course though.

Steve Rance said: It probably won't be the diff. That only locks under hard braking or acceleration. If you weren't pushing and you were on sports it's unlikely it's your geo unless the car is pretty much undrivable everywhere. More likely to be oil or Diesil on the road ie something external. I'd get your geo checked as a matter or course though.

When you looked up?

I've just replaced the PS2s on mine with a fresh set as they were 5yrs old. The rears were on 4mm and the fronts still on 6mm, I've put the fronts onto my daily driver and can't believe how little grip they have - they squeal in the dry and light up the ESP in the wet. Haven't driven the GT3 on its fresh rubber yet but I'm expecting a marked improvement.

What's a fast lane ? Then you looked up !! , where were you looking ?

Kawasicki said: When you looked up? Bingo!

OK, fair enough, I'll keep asking about and investigating the diff angle, but for the time being may have to conclude that one of 2 things happened .. 1- when checking the mirrors, I *must* have hit some standing water (surely, what else?) on the drivers side, (that must have been the twitch I felt,) the car, being lighter than the rest and only doing 70 (so little down-force), must have aquaplaned and pointed slightly right .. the rest is overcorrection/drivers error. 2- when the drivers side tyre lost traction for a second (due to standing water, roadkill, diesel), and I may have been accelerating lightly, the resulting speed differential in the wheels caused the diff to lock, and the resulting jolt forward on the left tyre with traction, further propelled me to the right .. the rest is overcorrection/drivers error. Whatever happened, better driving skills may have saved me. I never said I was good at handling this car, it seems like a bit of a handful compared to the BMW! When she goes, you've got to be quick and enter the exact right input to save yourself. The BMW would have never aquaplaned there and I do that stretch at 85mph always! I was purposely driving the Porsche 'slow' at 70 to be safe. Not slow enough! .. Oh, and I'll get the geometry checked again ASAP. So, how fast do you other Porsche guys drive on a (lets say) wet motorway? Is there anywhere I can go (apart from Silverstone) to learn how to drift this thing safely to improve my handling skills? I'm looking for carparks, flat tarmac'd areas, drift days at venues, lonely wide roads, etc. Edited by Posh868 on Wednesday 16th April 10:56 Edited by Posh868 on Wednesday 16th April 11:20

GT3 is not really a good road car full stop imo :-) But you get the lovers and the haters. I love them but not for road use. As for speeds, most people will be doing a ton plus in their Porsches on motorways even on damp roads on PS2, you see it every day. Porsche will only sell you a N spec tyre and think that a N spec CUP in the wet is safe as houses and send you on your way, but will not fit you a Pilot supersport and say that's unfit for your car and dangerous !! Not that you had cups on it, but then why even own A RS and fit PS2 anyway ? sell it and buy a car better made for the road is my advice :-), these cars are well over hyped on here. what's that, the 3rd straight line spin at legal speeds this year on this forum even inc the 991 GT3!!! if you guys are not spinning the things get over 80 mph on a B road and the cars unsettled again, I am sorry but what's the point of these cars on the road ? This is imho, so the normal posters can do one and not quote me :-) (likes that's going to happen lol ) Edited by mrdemon on Wednesday 16th April 11:30

mrdemon said: GT3 is not really a good road car full stop imo :-) But you get the lovers and the haters. I love them but not for road use. As for speeds, most people will be doing a ton plus in their Porsches on motorways even on damp roads on PS2, you see it every day. Porsche will only sell you a N spec tyre and think that a N spec CUP in the wet is safe as houses and send you on your way, but will not fit you a Pilot supersport and say that's unfit for your car and dangerous !! Not that you had cups on it, but then why even own A RS and fit PS2 anyway ? sell it and buy a car better made for the road is my advice :-), these cars are well over hyped on here. what's that, the 3rd straight line spin at legal speeds this year on this forum even inc the 991 GT3!!! if you guys are not spinning the things get over 80 mph on a B road and the cars unsettled again, I am sorry but what's the point of these cars on the road ? This is imho, so the normal posters can do one and not quote me :-) (likes that's going to happen lol ) Edited by mrdemon on Wednesday 16th April 11:30 You know whats going to happen here don't you? Its been done to death on loads of other threads. The GT3 is a brilliant road car, it just is. The things it does better than , for example, a Cayman R remain as strong an argument as ever. It does not throw itself off the road at the slightest whim nor does it typically spin in a straight line. It does give feedback that can make you nervous of what's happening because of the clarity of it. I do not accept its anything other than wonderful on a typical B road in the UK, it has enough compliance (Too much for a track day special IMO ) fantastic damping and its compact, seriously quick and sounds wonderful. Unless you really are using it for a high percentage of time on a track (In which case it needs altered geo and stiffer springs IMHO) then running softer, more compromised and more expensive cups is crazy. the PS2 is a pretty damn sensible option and gives 90% of the grip , superior grip in cold and damp conditions and immeasurably superior grip on a soaking wet road.

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mikem7709 said: I've just replaced the PS2s on mine with a fresh set as they were 5yrs old. The rears were on 4mm and the fronts still on 6mm, I've put the fronts onto my daily driver and can't believe how little grip they have - they squeal in the dry and light up the ESP in the wet. Haven't driven the GT3 on its fresh rubber yet but I'm expecting a marked improvement. This is a good point! The tyres were over 3 years old .. Rockster said: Even with new tires on my Porsches I slow down on damp roads. The tires do not play well with water on the road. And if it is cool, cold, you are just asking for trouble. 3mm tread depth is not worn out by the legal definition but I know from experience tires worn down to this point are slippery on damp roads like would not believe. Alignment, aka geo, is probably not a contributing factor though bad geo can result in uneven tire wear. Then what you have is are tires that are half good, half no good, if the wear is uneven across the rear tread faces, which is a good sign the geo is bad. When you replace the tires have the car treated to a proper geo to be sure you and the new tires start out right The 3mm comment is also a good point, reducing traction even further .. The tyres that it spun with are evenly worn, probably implying no geometry issue .. Steve Rance said: It probably won't be the diff. That only locks under hard braking or acceleration. If you weren't pushing and you were on sports it's unlikely it's your geo unless the car is pretty much undrivable everywhere. More likely to be a pack of oil or Diesil on the road ie something external. I'd get your geo checked as a matter or course though. yes id agree, diesel is a distinct possibility, thought that at the time.. I welcome all opinions; Mr Demon, post the links for the other straight line legal spins, I cant seem to find them and want to have a read of that. And when you're in an RS with your foot planted, you'll realise why the car is so addictive.. nothing compares! But yes, she's sometimes a scary monster.

Posh868 said: Whatever happened, better driving skills may have saved me. I never said I was good at handling this car, it seems like a bit of a handful compared to the BMW! When she goes, you've got to be quick and enter the exact right input to save yourself. The BMW would have never aquaplaned there and I do that stretch at 85mph always! I was purposely driving the Porsche 'slow' at 70 to be safe. Not slow enough! .. Oh, and I'll get the geometry checked again ASAP. So, how fast do you other Porsche guys drive on a (lets say) wet motorway? Is there anywhere I can go (apart from Silverstone) to learn how to drift this thing safely to improve my handling skills? I'm looking for carparks, flat tarmac'd areas, drift days at venues, lonely wide roads, etc. I can recommend a CAT driver training day at Millbrook. You can do a specific drift and over grip limit handling day. Even on a wet surface you will be quite surprised how much provoking it takes to get the car really out of shape, whether it be an old 911 or newer GT3. They'll get you spinning it eventually though.

Yea GT3s are rubbish road cars. For me a ford focus is more practical, has better mpg and rides better too. I don't get what all the fuss is about...

whats all this nonsense about ? the GT3 is a b h and i spanked it. TQ

seawise said: whats all this nonsense about ? the GT3 is a b h and i spanked it. TQ quoted so we know who has got a dodgy RS in the future ;-)

Rarely used tyres harden over time, they become pretty useless in the dry and dangerous in damp conditions Edited by SteelySteve on Wednesday 16th April 19:30

boxsey said: I can recommend a CAT driver training day at Millbrook. You can do a specific drift and over grip limit handling day. Even on a wet surface you will be quite surprised how much provoking it takes to get the car really out of shape, whether it be an old 911 or newer GT3. They'll get you spinning it eventually though. +1 a good mate of a mate. Highly recommended. Once you have this under your belt you will feel in charge again.

What's the point of buying the RS version if you don't fit decent/fresh(ish) tyres? Or at least have a shot at learning to drive it as it was designed to be driven? I'm confused. It's like spending 10k on a hifi and then not bothering to clean your ears.

Not everyone realises that as a matter of course. You only start asking questions when you start having problems!

I am neither a troll nor a GT3 doubter, but I kinda agree with a tiny bit of what MrD says. No car (on 3mm or otherwise) should spin in the circumstances described. External factors are hopefully to blame. It may just be internet hysteria, but I would currently think twice about driving a GT3 on a wet road, which is a shame.

ORD said: I am neither a troll nor a GT3 doubter, but I kinda agree with a tiny bit of what MrD says. No car (on 3mm or otherwise) should spin in the circumstances described. External factors are hopefully to blame. It may just be internet hysteria, but I would currently think twice about driving a GT3 on a wet road, which is a shame. Its ok, you grow a set of balls when you drive a gt3 on a wet road, they get hairy when you drive them on cups/without tc etc

ORD said: I am neither a troll nor a GT3 doubter, but I kinda agree with a tiny bit of what MrD says. No car (on 3mm or otherwise) should spin in the circumstances described. External factors are hopefully to blame. It may just be internet hysteria, but I would currently think twice about driving a GT3 on a wet road, which is a shame. For some it is the thrill of the 'unknown' ,exciting jitteriness and intense feedback that is part of the thrill of ownership of the GT3/RS. Most new cars are so 'safe' you may as well be playing a vidoe game. Each to their own of course. The bottom line is that with such a large patch of tyre in contact with the road they do not like standing water. I have driven on the autobahn on the outskirts of Brussels and had a few twitchy moments in heavy rain. It is a good reminder for drivers to adjust to the road conditions. I have looked for the 991 GT3 that spun and crashed for no apparent reason and it looks as if the post has been removed - probably 'legal' reasons. Pip

Once upon a time I stupidly drove to Spa on very worn cups when the heavens opened just south of Folkstone - and continued for most of the rest of the trip. Fingertip control, a tight sphincter and large cahunas were swung into action. By the time I got to Stavelot my underpants had been sucked into the old starfish and I couldn't see over the steering wheel thingy... My, how we larfed....

lemmingjames said: ORD said: I am neither a troll nor a GT3 doubter, but I kinda agree with a tiny bit of what MrD says. No car (on 3mm or otherwise) should spin in the circumstances described. External factors are hopefully to blame. It may just be internet hysteria, but I would currently think twice about driving a GT3 on a wet road, which is a shame. Its ok, you grow a set of balls when you drive a gt3 on a wet road, they get hairy when you drive them on cups/without tc etc Knock yourself out. I would rather take risks over which I have some control, especially with someone else in the car and others using the road. The idea that driving a car that might spin on a straight damp road makes you a real man is pretty laughable. By all means put feeling big ahead of the safety of yourself, your passenger and other road users if you must, but that makes you pretty much the same as a chav spinning around town at 50mph in a Corsa with an aftermarket exhaust.

Hang on, lets set some things straight shall we! The standard Cup tyres are amazing on hot dry days when they are fully warmed up The standard Cup tyres are really quite terrible on wet days cold or warm A brilliant compromise is the Michelin Pilot Super Sport As a whole, the 997 GT3 is a brilliant SAFE car that has never once spat me (or anyone I know who has driven one) off the road! It's a comfortable but stiffly sprung proper sports car that anyone (including my wife) can drive. There are many people who don't 'get' the GT3 and think its a massive compromise and I am getting tired of having to defend it whenever threads about the GT3 are posted.

note to self, "don't follow GT3 owners to close in the damp, esp ones with small non hairy balls " ;-p that's about all that's come out of this thread then :-)

mrdemon said: note to self, "don't follow GT3 owners to close in the damp, esp ones with small non hairy balls " ;-p that's about all that's come out of this thread then :-) + those that do drive in inclement weather, are quite clearly driving gods amongst you mere mortals

mrdemon said: note to self, "don't follow GT3 owners to close in the damp, esp ones with small non hairy balls " ;-p that's about all that's come out of this thread then :-) It actually sounds like the safest place to be is right behind them as they all spin sideways.

Porsche should probably stop selling cars on tyres that only work on the 23 dry days a year that we have in this country

I like to shave my balls as I find I get better head, so where do other road users stand around me ? Am I safe or a liability ? Maybe insurance companies should add in an extra question for wether you have hairy balls or not ??

Do you take an average across both (all?) of your balls? Is it a weighted average?

I believe the standardised approved method is to dangle them into a Spyder drivers mouth and get them to rate them on a saltiness scale from 1-100

gfreeman said: Once upon a time I stupidly drove to Spa on very worn cups when the heavens opened just south of Folkstone - and continued for most of the rest of the trip. Fingertip control, a tight sphincter and large cahunas were swung into action. By the time I got to Stavelot my underpants had been sucked into the old starfish and I couldn't see over the steering wheel thingy... My, how we larfed.... ;o) Holy crap, you guys do talk a load of junk. I got to laugh. lol Yea, you might be right, the old girl is a bit hard to handle, but back in the day the turbo was not an easy machine either!, the '73 Carrera RS used to spin out as well, they all do .. its that whole 'engine out over the back' thing .. you either love a 911 or you don't. Let me tell you again, put yourself in one of these, with your foot planted, and you'll understand why there's nothing like it.. crazy fast, and it howls!, 100mph in 2nd gear. In the dry this beast sticks like glue, but in the wet I'm going to be going really slow .. haha Please someone find the thread with the other Porsches spinning out and post the links. I got to read that. Edited by Posh868 on Friday 18th April 02:01

mrdemon said: note to self, "don't follow GT3 owners to close in the damp, esp ones with small non hairy balls " ;-p that's about all that's come out of this thread then :-) You'd struggle to keep up with them anyway, so I doubt it's much of a concern for you.

d41d8cd9 said: mrdemon said: note to self, "don't follow GT3 owners to close in the damp, esp ones with small non hairy balls " ;-p that's about all that's come out of this thread then :-) You'd struggle to keep up with them anyway, so I doubt it's much of a concern for you. You are making the assumption that all GT3's are driven as they were intended - my experience of encountering them on track doesn't support that assumption. Plenty are driven very well indeed, but not all!

Must have aquaplaned and you were unlucky to have your eyes off the road in front of you at the time. I got caught out in the rain one evening in my 7.1 GT3, roads wet enough for spray , with rear tyres just above legal limit. I was impressed at the speed one could keep up on the twisties, as long as driving very smoothly. I've also aquaplaned on motorways with the car, but was prepared for the upcoming standing water, whilst tightly clenching buttocks . No one likes to aquaplane ! Edited by Dave211 on Saturday 19th April 03:14

Perhaps a classic case of "watch this..."

I'm amazed at the number of people having moments in a straight line in these. Tyres aside for a minute, in theory, they should have more traction under power than most rwd, "high powered" cars because of the engine position. So we can't really blame it on the car. As far as the diff being aggressive goes, it's probably no more aggressive than some other diffs and surely only gets "aggressive" with the application of sufficient power. So are people really surprised that they lose traction when they are driven hard in the wet, under power? If people are losing them in a straight line when not under a lot of power, it has to be the tyres or the road surface. It's not an inherently dangerous car like it being made out to be. You'd get the same results in other cars with inappropriate tyres or inappropriate use of power eg an M3 (remember all the disclaimers about the CSL), TVR (all the myths about how dangerous they are) etc, etc. These cars demand a level of respect, not unlike many other cars.

If it was the cars everyone would complain of it!

It's so difficult to say what happened in this instance as none of us apart from the OP were there. My own experience is that GT3s have a lot of traction esp if you appreciate and work the weight situation to your advantage. They are pretty friendly in a drift, again if you get the physics. Never heard of one spinning in a straight line for no reason. 2 weeks ago I drove my 6.2 GT3 to Spa in probably the worst rain I have ever witnessed from inside a car - it performed faultlessly and was nicely confidence inspiring. Right tyres for the conditions and a great geo undoubtedly helped. Have heard some hairy stories on properly worn Cups, but then driving any car on slicks in the rain ain't gonna end well! Cheers Slodge

Last one looks like driving inappropriately for the conditions, middle one is the "Paul Walker" CGT? And with respect to the driver of the 991 gt3, not sure I buy the fact that the car was being driven at sensible speeds in a straight line and decided to throw a wobbly with no driver error or something to make it lose traction, eg, oil.

Posh868 said: OK, I found some straight line and other interesting threads on Rennlist .. I suppose it would be ok to post some links? 991 Written off at 50 mph while responsibly driving http://forums.rennlist.com/rennforums/991-gt3/8010... Pilot Sport tyres 'very cold weather sensitive' compared to others http://forums.rennlist.com/rennforums/porsche-supe... 997 Loss of control blamed on the PSM http://forums.rennlist.com/rennforums/997-turbo-fo... 3 More GT3's aquaplane at around 50mph in these posts http://www.pistonheads.com/gassing/topic.asp?h=0&a... This car (first in thread) aquaplaned at 70 .. http://www.pistonheads.com/gassing/topic.asp?h=0&a... Aquaplane at 40 mph http://forums.rennlist.com/rennforums/997-gt2-gt3-... Seems like slow speed aquaplaning is a huge issue! no matter what tyres you have .. Will edit and add more as I find them .. Without even looking at those threads, I can determine one thing: driver error caused those crashes. Nothing else. I'm completely baffled by the amount of s te being spoken in this thread! Christ, next you'll be telling me the GT3 is responsible for the disappernece of MH370! Cars don't just fall off the road (catastrophic mechanical failure notwithstanding). They have to be driven off the road.

Posh868 said: OK, I found some straight line and other interesting threads on Rennlist .. I suppose it would be ok to post some links? 991 Written off at 50 mph while responsibly driving http://forums.rennlist.com/rennforums/991-gt3/8010... Pilot Sport tyres 'very cold weather sensitive' compared to others http://forums.rennlist.com/rennforums/porsche-supe... 997 Loss of control blamed on the PSM http://forums.rennlist.com/rennforums/997-turbo-fo... 3 More GT3's aquaplane at around 50mph in these posts http://www.pistonheads.com/gassing/topic.asp?h=0&a... This car (first in thread) aquaplaned at 70 .. http://www.pistonheads.com/gassing/topic.asp?h=0&a... Aquaplane at 40 mph http://forums.rennlist.com/rennforums/997-gt2-gt3-... Seems like slow speed aquaplaning is a huge issue! no matter what tyres you have .. Will edit and add more as I find them .. Wasn't your original post looking to apportion blame on your event to the diff? You are now just posting random things that have happened to cars you have found on the internet. Maybe a secret govt test programme fired a pulse wave device at your car and knocked it off of the road? theres probably a post of that somewhere online to validate the hypothesis. The diff in the 997 is weak, really weak. It only has 28/40 lock up using friction discs that wear out very fast and has almost zero preload even when new. The weak diff is designed to ensure that TC can work away without interference. Unless you only have a handful miles on your car its likely that the diff is essentially open (and assuming you are still on a standard diff rather than a track upgrade using guard or similar) and incapable of doing anything. Anything is possible but its seriously unlikely that the diff caused your spin. Regular aquaplaning may very well be the cause though but no one will ever know. As for your links: 1. who knows what was going on there. 2. they are talking about MPSC, not PS2. totally different tire. 3. modified turbo with awd crashes in what looks like a typical aquaplane situation while doing the Gumball. OP blames PSM. Could be. You don't have PSM. I bet owner is glad he didn't fit lightweight doors as well as those front wings. 4. aquaplane while on MPSC. Others in thread agree that MPSC in the wet isn't fun. Im not sure you would find anyone to disagree. MPSC new have 4.76mm of tread IIRC. What were you at? 3-4mm? 5. driver aquaplaned and says so as part of a wider discussion about the merits and limits of TC. I don't see how any of those add anything to your view that the diff was your culprit or what seems like a position that the cars are somehow inherently treacherous. Indeed every single link is irrelevant unless the point is to show that aquaplaning can happen to Porsche cars just as it can with any other car. If that is your aim you could have just said so. No one will argue against that I am sure. It sucks that you had your incident, I am sure everyone feels that but I don't really see what you are looking for? Edited by fioran0 on Tuesday 22 April 20:32

Having just picked up my RS - this thread was in my thoughts whenever I prodded the throttle - there's an immense amount of power that can be unleashed in a 10mm movement of the foot - and at the wrong time on the wrong surface only bad things will happen... I'm sure with time I may become accustomed, however on MPSC's, cold mornings, damp patches, being wary of the environment is paramount to making progress.

OK, I found some straight line and other interesting threads on Rennlist .. I suppose it would be ok to post some links? 991 Written off at 50 mph while responsibly driving http://forums.rennlist.com/rennforums/991-gt3/8010... Pilot Sport tyres 'very cold weather sensitive' compared to others http://forums.rennlist.com/rennforums/porsche-supe... 997 Loss of control blamed on the PSM http://forums.rennlist.com/rennforums/997-turbo-fo... 3 More GT3's aquaplane at around 50mph in these posts http://www.pistonheads.com/gassing/topic.asp?h=0&a... This car (first in thread) aquaplaned at 70 .. http://www.pistonheads.com/gassing/topic.asp?h=0&a... Aquaplane at 40 mph http://forums.rennlist.com/rennforums/997-gt2-gt3-... Lots of track accidents, but all reinforce that in the wet these cars are very hard to handle and will spin on you unpredictably, many experienced drivers left scratching their head .. http://forums.rennlist.com/rennforums/997-gt2-gt3-... Seems like fairly slow speed aquaplaning is a huge issue! no matter what tyres you have .. Its very easy to say 'I don't believe he was going that slow', or 'oh that guy was going too fast' or 'should be going slower in the wet', or 'that man cant drive'. But how slow is slow enough? 60mph on the motorway in the wet without rain? 50? 40? I feel that I have done enough research now to determine that: 1. most if not all of these stories are in fact true, it has happened to me, and like me these guys have nothing to loose by sharing factual accounts of what happened 2. the GT3 should be driven exceptionally slowly and carefully in the wet, there are just too many accounts of loss of control in wet conditions at legal speeds 3. standing water is extremely hazardous to these cars due to the light front-end 4. unpredictable spins can occur in the wet with no warning which require a large amount of skill (much more so than for any other car) to overcome In closing, one comment that stuck is when asked "what tyres do you put on your GT3 in the wet?" one experienced driver said "slicks! because she goes right up onto the trailer" - haha - no wet driving at all for him! So when you pass a 997.1 GT3 RS going 50mph in the slow lane in the wet, that'll be me! .. and I'll be laughing at how ridiculous it is as well! Edited by Posh868 on Tuesday 22 April 21:06

Yes, based on the feedback and research, I've all but ruled out the diff as the issue. I do believe that in summary all those links conclude that the car (911 in general, possibly GT3 especially) can be unpredictable, and if this thread serves for others to be overly careful with theirs, then great. I for one am totally surprised by the findings and totally didn't expect this behaviour from the car. And yes again, if you were a terrifically experienced driver, with much drifting and car control under your belt, and lightening fast reflexes; you may stand a chance when she decides to go. But .. if you're like me with only 8 trackdays, no racing experience, and a moderate knowledge of car control, you've a high risk of crashing. So be careful.

Had ps2's on an Audi a few years back, in the cold weather they went like a sort of plastic and were shockingly bad below 6C

Oh boy, the internet has a lot to answer for sometimes. Its not the car thats the unpredictable thing in this equation.

Posh868 said: the car (911 in general, possibly GT3 especially) can be unpredictable no

Never had any issues in my last GT3 which was tracked in all weathers, and driven across Europe!!

ruebdo said: Never had any issues in my last GT3 which was tracked in all weathers, and driven across Europe!! And you're still alive?

Yes I am :-)

ruebdo said: Never had any issues in my last GT3 which was tracked in all weathers, and driven across Europe!! +1 Never had a problem with over 4 GT3s, different weather situations, tyres, temperatures, speeds, etc, etc. Yes, I did once...but that was due to aggressive driving in the wet...and even then it was only a wheel spin (admittedly cold, wet, and rear tyres which were almost slicks!)

ruebdo said: Yes I am :-) You sir, get the upgrade to a hairy chest.

Posh868 said: .. if you're like me with only 8 trackdays, no racing experience, and a moderate knowledge of car control, you've a high risk of crashing. So be careful. I have NO racing experience I have NO drifting experience and I have done LESS than 8 trackdays I spanked my 997.1 GT3 across Europe in the rain, snow, sleet and fog and I am alive to tell the tale! Posh868, not wishing to cast apersions here but are you SURE its the car at fault? If you are then please check the geo and try replacing the tyres with Michelin Pilot Super Sports.

Posh868 said: Yes, based on the feedback and research, I've all but ruled out the diff as the issue. I do believe that in summary all those links conclude that the car (911 in general, possibly GT3 especially) can be unpredictable, and if this thread serves for others to be overly careful with theirs, then great. I for one am totally surprised by the findings and totally didn't expect this behaviour from the car. And yes again, if you were a terrifically experienced driver, with much drifting and car control under your belt, and lightening fast reflexes; you may stand a chance when she decides to go. But .. if you're like me with only 8 trackdays, no racing experience, and a moderate knowledge of car control, you've a high risk of crashing. So be careful. ......especially if you take your eyes off the road.

So have none of you felt your cars go all floaty in the wet on worn tyres?

IanHg said: So have none of you felt your cars go all floaty in the wet on worn tyres? Yes, but that does not mean the GT3 and 911's in general are dangerous. It just means you need new tyres

lemmingjames said: You sir, get the upgrade to a hairy chest. Thanking you sir. I feeler stronger today already :-)

IanHg said: So have none of you felt your cars go all floaty in the wet on worn tyres? Yes, on Cups , absolutely. I never suffered any similar symptoms on PS2s even in cold/wet conditions and even when they were near the end. The MPSS are too new to know yet but seem immense when its warm and dry especially. There's a LOT of feedback through the wheel and the seat of your pants in GT3s, any moving around at all is communicated transparently, can make the driver feel more nervous than he needs to. It's break away characteristics on properly set up Geo are however very benign indeed IME. Pretty friendly TBH and not likely to deposit you in a hedge.

Dblue said: Pretty friendly TBH and not likely to deposit you in a hedge. Especially in a straight line! Unless of course you drive at the hedge

I've a 7.1RS, owned for 3 years now, have little balls, no hair on my chest and only a few trackdays under my belt. I've driven my car in most weathers (up in NE Scotland so sh!te weather a lot of the time)and only twice have I scared myself, both times when I was caught on the dual carriageway when there was standing water covering both lanes. 50mph on 3mm P Zero corsa's and the TC light flashing as "normal" cars and jeeps flew past, raised my heart rate a few beats but it was all to do with the depth of water and the limited tread depth, not the car. In "normal" rainy days it's fine and doesn't try to kill me

V8KSN said: Yes, but that does not mean the GT3 and 911's in general are dangerous. It just means you need new tyres Well yes. God's way of telling you to stop being tight and buy new boots

Dblue said: Yes, on Cups , absolutely. I never suffered any similar symptoms on PS2s even in cold/wet conditions and even when they were near the end. The MPSS are too new to know yet but seem immense when its warm and dry especially. There's a LOT of feedback through the wheel and the seat of your pants in GT3s, any moving around at all is communicated transparently, can make the driver feel more nervous than he needs to. It's break away characteristics on properly set up Geo are however very benign indeed IME. Pretty friendly TBH and not likely to deposit you in a hedge. I don't see it as a GT3 thing. I suspect that any wide tyre with a shallow tread (either track tyres or well worn road tyres) make aquaplaning quite likely. Maybe a light front end makes it more likely. I know that I slow down quite a lot on the motorway when it's wet - narrow tyres and lots of weight seem much better in the wet - white vans get even faster.

martinr007 said: I've a 7.1RS, owned for 3 years now, have little balls, no hair on my chest and only a few trackdays under my belt Turn off TC and everything will grow ;-)

V8KSN said: If you are then please check the geo and try replacing the tyres with Michelin Pilot Super Sports. so you want him to fit a tyre Porsche does not even approve ?

mrdemon said: V8KSN said: If you are then please check the geo and try replacing the tyres with Michelin Pilot Super Sports. so you want him to fit a tyre Porsche does not even approve ? Yes, why not, it doesn't go back and retro approve new tyres for older models. The MPSS is a quantitive improvement on a PS2 for example , or else what the hell are Michelin playing at, but NOT N Rated for a 2007 GT3. So fitting a better, improved tyre that was not around when the car was new makes a lot of sense.

IanHg said: I don't see it as a GT3 thing. I suspect that any wide tyre with a shallow tread (either track tyres or well worn road tyres) make aquaplaning quite likely. Maybe a light front end makes it more likely. I know that I slow down quite a lot on the motorway when it's wet - narrow tyres and lots of weight seem much better in the wet - white vans get even faster. I suspect this is spot on. Wide surface to slide over the water and not a huge amount of tread to filter it away. The relative lightness of the front end is probably not a help, especially under acceleration taking the weight backwards. Might this also explain why lowish speeds are bad - less downforce? I also agree with the chap that said that you are more aware of things getting dicey in a Porsche. I can feel what is going on with the tyres in the wet (987.2 S), whereas in crap cars I feel nothing through my hands, feet and arse so only know something is wrong when the car actually moves sideways or refuses to slow. I suspect that people driving cars with less feedback get close to the limits in the wet without even knowing it, whereas Porsche drivers poo themselves as they feel how little grip they actually have.

Dblue said: Yes, why not, it doesn't go back and retro approve new tyres for older models. The MPSS is a quantitive improvement on a PS2 for example , or else what the hell are Michelin playing at, but NOT N Rated for a 2007 GT3. So fitting a better, improved tyre that was not around when the car was new makes a lot of sense. The simple reason is Cars don't spin in a straight line due to PS2’s. The ps2 is a awesome tyre. Like most spins it's driver error, fitting better tyres just means next time it spins it will be doing it at a far greater speed.

mrdemon said: V8KSN said: If you are then please check the geo and try replacing the tyres with Michelin Pilot Super Sports. so you want him to fit a tyre Porsche does not even approve ? Yes I do! I think it might help.

mrdemon said: Dblue said: Yes, why not, it doesn't go back and retro approve new tyres for older models. The MPSS is a quantitive improvement on a PS2 for example , or else what the hell are Michelin playing at, but NOT N Rated for a 2007 GT3. So fitting a better, improved tyre that was not around when the car was new makes a lot of sense. The simple reason is Cars don't spin in a straight line due to PS2’s. The ps2 is a awesome tyre. Like most spins it's driver error, fitting better tyres just means next time it spins it will be doing it at a far greater speed. Have you actually thought that through? That's no argument at all against fitting MPSS on a 2007 Porsche. The PS2 is a fine tyre I quite agree. The MPSS is a few per cent better still. Its progress. For its day the P7 was "awesome" but I wouldn't suggest that it hasn't been surpassed comprehensively over the intervening years and nor would you. If Porsche would go to the trouble of N Rating newer tyres as they come to market for specific models then I would wholeheartedly back you up on the N Rated point, but they don't. I HATE Cups on road cars personally , I don't think they should be legal, on standing water when well worn they are the reason for most of these aquaplane moments but they are most definitely "Porsche Approved" for GT3s