alank Posted November 13, 2017 Report Share Posted November 13, 2017 Hi clive. After getting my Boxster S 18 months ago, I noticed the exact Skipping across lines you are experiencing, and a general feel of the back end not that stable . I told the indy that supplied me the car when it was in for something unrelated, the next thing I know was they had replaced the rear dampers ( under their warranty) for me as they said they were both gone. When I got the car back it was like driving another car. Hope this helps. alan Link to comment Share on other sites More sharing options...
That986 Posted November 13, 2017 Report Share Posted November 13, 2017 What temperature was it outside? If anything like London yesterday fairly cold and i'm hazarding a guess that you're running a "summer" tyre? Summer tyres are at their best when used at temps above 5degC if I remember rightly, below that they will be compromised like any other summer tyre. Factor in the damp on the road and it's no wonder it's skipping around. Drive to the conditions, not your ability. Link to comment Share on other sites More sharing options...
map Posted November 13, 2017 Report Share Posted November 13, 2017 13 hours ago, Clivescoobydo said: Apologies if I'm repeating a previous post but I went for a drive down the A24 yesterday and nearly lost the rear twice. The P zero tyres on the rear are showing signs of wear in the middle, the road was greasy damp and I'm used to 4 wheel drive but to loose the rear end at slightly faster than normal speeds was a bit disconcerting. I had a smile but the wife went quite for 20 mins! (every cloud has a silver lining lol). I also noticed the rear end 'skipping' across white lines/cats eyes during lane changing. By just pushing today, the rear shocks feel soft and bouncy so I'm assuming thier the first thing to replace? The car recently passed an MOT not that it means much. Appreciate your comments and any guidance on cost, thanks. A few questions: Has the car got modified suspension of any sort? Are the Sport Design wheels OE Boxster spec, after market or "911" type? Suspect it's all standard Boxster but want to double check. Has the wear in the centre of the tyres worsened relative to the rest of the tyre since you corrected the pressures? And one last query: When the car lost grip at the rear axle did it arrive "suddenly" which you caught? Or could you feel it "falling away" and you contained it? If it was a "sudden" loss then based on personal experience it sounds like the dampers are tired and not controlling the chassis movement properly. This combined with poor geometry - especially toe angles as already mentioned - can generate unwanted outer rear wheel toe out under compression. This equals uncontrolled rear wheel steering - and that's not nice..... The choppiness you describe also points to dampers/suspension as has already been suggested. If the grip "fell away" then again based on my own experience it is more likely a combination of tyre condition, road surface and driver input. Having been through a similar loop, albeit trackday use of my daily driver 986S, I'd be pushing for a diagnosis before spending any money on new stuff - tyres/suspension parts - and then I'd aim get all the bits updated/replaced at the same time. Don't see the Boxster as problematic in the wet - sure we need to recognise the physics of what we're doing (especially when making progress) but in terms of grip it's all good. Regardless I would echo comments on having the suspension checked over by someone who really knows what they're doing with Boxsters. A good specialist will walk you through the options for your car and the amount/type of use it gets. Link to comment Share on other sites More sharing options...
That986 Posted November 13, 2017 Report Share Posted November 13, 2017 12 hours ago, Clivescoobydo said: I'm having trouble on twisty damp A roads at the speed limit say 50 mph. Somethings not right and I can't believe it's just the P Zero tyres at low tread levels. I'll post some pics of my current tyre condition for opinions and probably use EPorsch for a check in due course. Kinda worries me though that owners don't rate the Boxsters handling in the wet ? With its low C of G and 225/255's for me that should still be better than the average car. I've has P-Zeros on for the last few months and several thousand miles (daily driven) and found them to be very grippy and sure-footed no matter the weather, far better than the Bridgestones and Continentals although the Continentals were that old when I got them they should have been in a museum but that's a different story for another day. Check the age of the tyres and i wouldn't be surprised if they're ancient, for some reason some people don't like driving their cars which means all the rubber bits (including tyres) dry out and lose any flexibility and therefore grip they ever had. If you're near East London feel free to call round and feel the grip levels on newer Pirellis that have been bedded in. Link to comment Share on other sites More sharing options...
james_ly Posted November 13, 2017 Report Share Posted November 13, 2017 What speed and how much throttle when it broke away? This time of year on wet cold roads it doesn't take much... I tested the other day on a quiet junction and could spin the wheels all through 1st and some of 2nd gear... Link to comment Share on other sites More sharing options...
Clivescoobydo Posted November 13, 2017 Author Report Share Posted November 13, 2017 Thanks everyone really appreciate your comments and I plan to get everything described checked. I'll get new tyres and the alignment/shocks checked at the same time. Map - to my knowledge and the paperwork the suspension/wheels are standard. It broke away suddenly which I caught at speeds I would not expect that to happen so was a bit disconcerting. As a motorcyclist that's managed to survive for a number of years I always ride to the conditions (touched wood). That986 - thanks for the offer but I'm on the west side of London. James_ly - probably around 50, with no more than 30% throttle just maintaining speed. Strangely its not spun up on pulling away.....which to me would indicate something other than the tyres. Current tyres are fronts Dunlop SP Sport 9090 225/40ZR18 and rears 265/35ZR18N4 and they were fitted July 13 at 25500. Cant be certain when the fronts were fitted but they look newer to me. Cars now done just under 40K miles. Link to comment Share on other sites More sharing options...
map Posted November 13, 2017 Report Share Posted November 13, 2017 15 minutes ago, Clivescoobydo said: Thanks everyone really appreciate your comments and I plan to get everything described checked. I'll get new tyres and the alignment/shocks checked at the same time. Current tyres are fronts Dunlop SP Sport 9090 225/40ZR18 and rears 265/35ZR18N4 and they were fitted July 13 at 25500. Cant be certain when the fronts were fitted but they look newer to me. Cars now done just under 40K miles. One piece of advice I'd push on this matter is to get the dampers and suspension bushes checked by a pukka Porsche specialist (not Porsche Dealers) before you go to reworked geometry and new tyres. The tyres on the rear seem old to me - there is a date code on the tyre somewhere and it is easy to look that up via google or similar to find the date they were produced. In my mind anything over 4 years with little use is a prime candidate for replacement for all the reasons mentioned by others earlier. Which bit of W London are you in? There are some gems in terms of specialists on this side of town. Link to comment Share on other sites More sharing options...
edc Posted November 13, 2017 Report Share Posted November 13, 2017 I've just googled a few images of Pirelli P zero tyres. I'm not a tyre or Pirelli expert but most of the images show visible sipes and cuts across the full tread width with the centre band tread block with sipes/cuts from either side but not quite meeting up in the middle. On your tyres it looks like the 3 central bands have worn away. Link to comment Share on other sites More sharing options...
Clivescoobydo Posted November 13, 2017 Author Report Share Posted November 13, 2017 43 minutes ago, map said: One piece of advice I'd push on this matter is to get the dampers and suspension bushes checked by a pukka Porsche specialist (not Porsche Dealers) before you go to reworked geometry and new tyres. The tyres on the rear seem old to me - there is a date code on the tyre somewhere and it is easy to look that up via google or similar to find the date they were produced. In my mind anything over 4 years with little use is a prime candidate for replacement for all the reasons mentioned by others earlier. Which bit of W London are you in? There are some gems in terms of specialists on this side of town. Both Eporsch and GT One are nearby so was going to sound them out. Assume thats the gems you refer to over this side? Link to comment Share on other sites More sharing options...
map Posted November 13, 2017 Report Share Posted November 13, 2017 Both of these are highly recommended as are No5 Garage in Chiswick, W3 Haven't used any of these but the names keep popping up as being amongst the good guys - would also recommend Precision Porsche on the strength of one of the blokes working there who used to look after my own car before I moved it because my work changed location. If you think you might go to Precision let me know and I'll PM you the chap's name. Link to comment Share on other sites More sharing options...
That986 Posted November 13, 2017 Report Share Posted November 13, 2017 1 hour ago, map said: The tyres on the rear seem old to me - there is a date code on the tyre somewhere and it is easy to look that up via google or similar to find the date they were produced. In my mind anything over 4 years with little use is a prime candidate for replacement for all the reasons mentioned by others earlier. July 13 and probably not brand new when fitted i'll wager, so you're looking at tyres getting on for 5 years old and done 14000 miles which would make them prime candidates for being worn and replacement. Link to comment Share on other sites More sharing options...
james_ly Posted November 13, 2017 Report Share Posted November 13, 2017 Well... hope you get it sorted. My betting is just on old tyres. If the toe or camber was out I'd assume the edges of the tyre would wear, not the middle. Plus it might wander a bit in a straight line. The wear points to overinflation? (which would explain twitchyness too). Dampers... well mine are original (I think) and on 135k miles so although it depends on the roads you drive etc... I'd be surprised if they were broken. Link to comment Share on other sites More sharing options...
Greenman Posted November 13, 2017 Report Share Posted November 13, 2017 16 hours ago, RBD914 v2 said: Don't know why some people sl*g off the Pirellis, I've had them on all my Porsche's over the years and never had an issue with them! Still got them on my 987.2 and I had no grip problems in wet conditions at a brisk pace on the recent Borders run, nothing wrong with Pirellis in my opinion. Yeh, nothing wrong with Pirelli IMO. It’s not like you have got some cheap Chinese made ditchfinders on. I had pretty well worn PZERO on my 981all through last winter with no grip issues (obviously you don’t push it much when wet and cold though). 25 minutes ago, That986 said: July 13 and probably not brand new when fitted i'll wager, so you're looking at tyres getting on for 5 years old and done 14000 miles which would make them prime candidates for being worn and replacement. Yes check the DOT markings for the manufacturing date, if over 6 years old this COULD be an issue. However that picture above doesn’t look like my PZeros, mine have asymmetrical tread with wider blocks on the outside edge. I suspect you have an alignment or suspension issue Link to comment Share on other sites More sharing options...
That986 Posted November 13, 2017 Report Share Posted November 13, 2017 51 minutes ago, Greenman said: Yeh, nothing wrong with Pirelli IMO. It’s not like you have got some cheap Chinese made ditchfinders on. I had pretty well worn PZERO on my 981all through last winter with no grip issues (obviously you don’t push it much when wet and cold though). Yes check the DOT markings for the manufacturing date, if over 6 years old this COULD be an issue. However that picture above doesn’t look like my PZeros, mine have asymmetrical tread with wider blocks on the outside edge. I suspect you have an alignment or suspension issue Not could, will be an issue. When tyres get little use they dry out and become pretty useless. The Pirellis i have now take a good amount to get spinning up whereas the Continentals that were on before spun up everywhere and were potentially lethal in the wet even though they looked like they had plenty of tread. Link to comment Share on other sites More sharing options...
911-32 Posted November 13, 2017 Report Share Posted November 13, 2017 Someone got there before me - check the date stamp. It will have the week and year of manufacture, like "0911" being the 9th week of 2011. Older tyres with plenty of tread look fine and work ok in the dry but are lethal in the wet. If a car is driven fast it will heat cycle the tyres and there is only so many times you can do that before they get hard. Its more of a problem with track days and track tyres but that plus age will kill an otherwise healthy looking tyre. Someone else said rear toe in will make it twitchy. Other way round - rear toe out makes it twitchy. Toe-in make the car want to track in a straight line, while rear toe out makes it twitchy and front toe out makes it darty (technical terms). Link to comment Share on other sites More sharing options...
the baron Posted November 14, 2017 Report Share Posted November 14, 2017 15 hours ago, map said: Both of these are highly recommended as are No5 Garage in Chiswick, W3 Haven't used any of these but the names keep popping up as being amongst the good guys - would also recommend Precision Porsche on the strength of one of the blokes working there who used to look after my own car before I moved it because my work changed location. If you think you might go to Precision let me know and I'll PM you the chap's name. I’ve had a very bad experience with No5, don’t touch with a barge pole. Link to comment Share on other sites More sharing options...
spyderman8 Posted November 14, 2017 Report Share Posted November 14, 2017 On 12/11/2017 at 8:13 PM, RBD914 v2 said: Don't know why some people sl*g off the Pirellis, I've had them on all my Porsche's over the years and never had an issue with them! I used to defend PZero Rossos till I switched to Michelin PS4 - night and day - the car is so much more confident in the wet. If the OP's tyres are showing wear just in the centre, something's wrong. You have a way less than optimal contact patch - it's like fitting tyres of only one third the proper width. Link to comment Share on other sites More sharing options...
ians Posted November 14, 2017 Report Share Posted November 14, 2017 Wear in the centre may be the result of over inflation. Link to comment Share on other sites More sharing options...
Terryg Posted November 14, 2017 Report Share Posted November 14, 2017 19 hours ago, james_ly said: Well... hope you get it sorted. My betting is just on old tyres. If the toe or camber was out I'd assume the edges of the tyre would wear, not the middle. Plus it might wander a bit in a straight line. The wear points to overinflation? (which would explain twitchyness too). Dampers... well mine are original (I think) and on 135k miles so although it depends on the roads you drive etc... I'd be surprised if they were broken. Anybody else have an opinion on this because in mine there is a very high liklehood that the dampers are well shot on a Porrsche with 135K unless it was all driving Miss Daisy stuff. Link to comment Share on other sites More sharing options...
james_ly Posted November 14, 2017 Report Share Posted November 14, 2017 10 minutes ago, Terryg said: Anybody else have an opinion on this because in mine there is a very high liklehood that the dampers are well shot on a Porrsche with 135K unless it was all driving Miss Daisy stuff. I believe it's on the original clutch too so I think it has sit on the motorway for most of its life... Link to comment Share on other sites More sharing options...
Terryg Posted November 14, 2017 Report Share Posted November 14, 2017 Just now, james_ly said: I believe it's on the original clutch too so I think it has sit on the motorway for most of its life... Okay sounds reasonable but I think we should bear in mind that many Porsches are not driven that way so yours is the exception rather than the rule (again IMO). My car had 79k on it and the suspension was not good once I got to about the legal limit on motorway bends and I don't think that my experience is that unusual. Link to comment Share on other sites More sharing options...
Nobbie Posted November 14, 2017 Report Share Posted November 14, 2017 17 minutes ago, Terryg said: Anybody else have an opinion on this because in mine there is a very high liklehood that the dampers are well shot on a Porrsche with 135K unless it was all driving Miss Daisy stuff. When I got mine at 140k I thought the dampers would have been replaced by now, but no record of it being done and it all seems pretty solid. Will be interesting to play with the dampers when I replace the rear springs to see how much life they have in them. It might be that higher mileage cars are driven as transport most of the time, whereas low mileage cars are more often taken out to 'drive' with consequent higher wear on components. Link to comment Share on other sites More sharing options...
Menoporsche Posted November 14, 2017 Report Share Posted November 14, 2017 51 minutes ago, Terryg said: Anybody else have an opinion on this because in mine there is a very high liklehood that the dampers are well shot on a Porrsche with 135K unless it was all driving Miss Daisy stuff. Yes, my opinion is he should get an expert to actually look at the car rather than doing any more virtual diagnosis Link to comment Share on other sites More sharing options...
edc Posted November 14, 2017 Report Share Posted November 14, 2017 1 hour ago, Terryg said: Anybody else have an opinion on this because in mine there is a very high liklehood that the dampers are well shot on a Porrsche with 135K unless it was all driving Miss Daisy stuff. Take each car as it comes. But generally yes the dampers do deteriorate over time. A little bit each year and its hard for you as the owner to recognise it. I've had 2 986 now and replaced suspension on both and noticed considerable improvements both times. 2000 S with 65 k change from standard to M030. Original suspension was actually in decent order as proven by Centre Gravity test rig. 2004 550 118k change from M030 to Koni FSD/H&R. Not a like for like change so more difficult to draw comparisons but by design the new suspension has a softer edge initially before firming up. Also having experienced new M030 vs 118k M030 I was in a good position to compare and my newly suspended old car would have run rings around my 550 with old M030. Link to comment Share on other sites More sharing options...
james_ly Posted November 14, 2017 Report Share Posted November 14, 2017 Could also be knackered bushes causing (more than usual) geo changes under load? I think mine has a bit of this... Link to comment Share on other sites More sharing options...
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