YW Sin Posted March 2, 2004 Share Posted March 2, 2004 I need some serious help on this. The most disappointing feature about my seven is its stopping power. It is just about the worst stopping car I have ever driven. To be brutally honest! I blamed this on the lousy old Michelin tires and have just changed to new Yoko A021R, absolutely confident that my car will now stop like a Styrofoam block hitting a brick wall……… But NO! I just came back from my first drive with new tires and this is what happened. First impressions, heavier steering and tire noise which I never heard with the old Michelins. Tire are picking up small stones and throwing to the inner wheel arch- I thought this is a good sign showing that the Yokos are indeed very soft and sticky. Driving out of the garage on the cold tarmac, the car definitely feels more squashed to the asphalt and my confidence already grows sky high. Now the first surprise, I came to join a nice empty main road; I half floored the car and turned right, to my surprise, the rear end sticked out too easily though very progressively, I guessed the tires are still too new. Soon after, checking the rear view mirror, I apply generous amount of pressure on the brake and the front left brake lock and the car skids just as it did before with the old tires. I decided to go for some drive hoping that the tires might loosen up a bit. Took the car to the Bois de Boulogne Park and do a few wheel spins and so on. After 7 odd miles, I tried the breaks again, but the same story, the front left wheels locks up just too easily and I could even see blue smokes. Came back home and checked the tire pressures, strangely, the pressure has gone down to just 1 bar instead of 1.4 bars which I have adjusted 3 days ago. Now I am wondering……. - I know that the Yokos are good tires but the car is still not stopping as it should. Is it because; The tires are still too new? The tarmacs are too cold? ( it is about 1 degree out there) My brakes are unbalanced? (But passed the French MOT involving brake tests long so long ago) Or am I just a lousy driver? Also, why has the pressure dropped on three tires except one? I don’t think I will sleep well tonight. A ll standard, Classic 1.7 X-flow Edited by - yw sin on 2 Mar 2004 23:23:52 Link to comment Share on other sites More sharing options...
Red SLR Posted March 2, 2004 Share Posted March 2, 2004 Sounds like the brakes are working ok to me if the wheels are locking up? Link to comment Share on other sites More sharing options...
YW Sin Posted March 2, 2004 Author Share Posted March 2, 2004 it is always the front-left wheel which locks up Link to comment Share on other sites More sharing options...
caterhamnut Posted March 3, 2004 Share Posted March 3, 2004 Just putting the 'sticky' tires on will not transform the car - well, they will, but not magically in all conditions! What I mean is, the cold conditions will have a big effect. 7 miles and a few wheel spins will not heat the tires up to become 'sticky' as such (however much fun it is 😬) I have 48's - very similar compound for the purposes of this discussion - when I first go out on them in this weather there is almost no grip when 'playing' - ie pulling out of t-junctions and provoking a nice slide at very low revs. Believe me, when conditions are warmer (tires and tarmac) they stick like 😳 to a 😳! 😬 There may well still be some release agent on them - more noticable when its wet or damp, so take care. Don't worry YW - sleep well tonight - its not you or your car (probably) but more than likely the cold weather. I can get my wheels to lock up, and I suspect if I did it all the time I might notice that one wheel was more inclined to lock up first. I agree with Simon - unless one wheel is locking up at 30kmh and you are still moving along without slowing down, I guess it shows they are working! Don't do it 'too' much - these tires will wearaway more quickly than the everlasting Michelins you have replaced. I have to keep telling myself to stop spinning the rear wheels so much 😬 Pressure drop - don't know. We have our tires at 17psi normally. Could put 18psi in these colder conditions but to be honest I don't bother. Leaking valves? Not a good seating on the rims (were they 'dirty' - the rims? - perhaps slightly corroded?) Pump 'em up and keep an eye on it - if it keeps happening then perhaps go back to whoever fitted them and ask them to take a look. Different noise is also normal - I noticed it when I went from 32's to 21's - more 'knobbles' (blocks) on the 21's, so you get that slight 'whine' on smooth tarmac that you hear when an old Land Rover goes past on off road tires (but obviously much quieter!) It works th eother way around as well - if you move to 32's or 48's later you will be amazed how much quieter they are - until you 'slap' a 'catseye' or drain! I am sure you are not a lousy driver - just take it easy 'finding the limit' of the new tires on the road (did you not have a little incident a few weeks back that prompted the change ) - take that the right way by the way - not preaching. Although the tires will be a huge improvement when it is a little warmer, they still have limits and will not always save you! I know it is harder to do in central Paris, but try them on a track and you will be amazed - slam the brakes on when they are warmer and you WILL feel the difference. If you are still not happy about the braking of your car, perhaps check your pads, both for wear and type. Have fun - you made the right decision changing from the Michelins - give it time and you will agree 😬 😬 NEW Nurburgring Pictures posted here 55,000miles in 2.5 years Link to comment Share on other sites More sharing options...
caterhamnut Posted March 3, 2004 Share Posted March 3, 2004 Of course when I say be careful, I do of course mean about hanging around the Bois de Boulogne Pak - 'doing donuts' might mean something completly different there! 😬 NEW Nurburgring Pictures posted here 55,000miles in 2.5 years Link to comment Share on other sites More sharing options...
caterhamnut Posted March 3, 2004 Share Posted March 3, 2004 I guess you must be sleeping after all - time for me to go as well I guess.... NEW Nurburgring Pictures posted here 55,000miles in 2.5 years Link to comment Share on other sites More sharing options...
thinfourth Posted March 3, 2004 Share Posted March 3, 2004 Corner wieghts or maybe a sticky caliper Blatting round aberdeen wondering wether to buy a jumper or heater Link to comment Share on other sites More sharing options...
Anthony Posted March 3, 2004 Share Posted March 3, 2004 Hi, I may be well "out of date" here, but was advised with Yokos ( and I am going back to good old 001R's)that they needed to "run in" for a 100 miles or so to get best performance. This then I have only run ACB10's which definately need a bit of heat in them - but are then fantastic ! Tyre pressure will also affect balance and braking Temperature will signifcantly improve grip, but breaking should be uniform albeit front/rear will be slightly different. Does one front lock immediately before the other ? ie is it a marginal difference or a signficant difference. If significant suggest overhaul of calipers. Anthony Raceco can on and it looks stunning Link to comment Share on other sites More sharing options...
John E Posted March 3, 2004 Share Posted March 3, 2004 I've got the same set up on my 1990 X flow and I think that its the dogs nuts, I;ve never seen the need to go for twin pot whatsits or sky blue pads or green thingys at all and ask any one who knows me, I dont hang around. If your car is pulling to one side, not withstanding correct tyre pressures, road camber etc then there is a problem. If one of the fronts is locking then look at its opposite, maybe a sticking caliper, maybe there is air in that side, maybe the pads are unevenly worn or glazed on one side. Worn wheel bearings, knackered track rod end, steering geometry incorretc. These things need checking out. I dont think that it has anything to do with the tyres providing the pressures are the same. If its the rear and a live axle then sticking shoes, lazy/weeping cylinder, distorted drum. Run Baby Run does it really have anything less than full throttle Link to comment Share on other sites More sharing options...
YW Sin Posted March 3, 2004 Author Share Posted March 3, 2004 Thanks angus&tessa, thinfourth, Anthony and John E ! Bois de Boulogne is my favourite place to test my.... errr,,,,, car. Just a few minutes drive from here and there are some hidden roads which are mostly empty at night. I think it may be possible that I my steering geometry has something to-do with one wheel locking up earlier. I did tamper with it before as previously it was set to toe out which is what I can describe as, nerve wrecking even though it makes the car turns in rather well. The car stops without pulling to one side but when brake is applied hard, there is a slight "twitch" (left to right) on the steering wheel. Angus's comment is assuring, I think I will have to run the tires a hundred Kms and wait for the warmer weather. Also, I think I should pay a little visit to UK to have the car checked by Seven specialist and do the MOT thing... my car UK registered. Link to comment Share on other sites More sharing options...
Super_Rich_Bernie Posted March 3, 2004 Share Posted March 3, 2004 I bought new tyres in the autumn (not for my 7), left the car in the garage for the week, and came out to find one tyre flat, and 2 more low. This was caused by poor sealing between the rims and tyres, in my case. The tyres had to come off, the rims cleaned up, and then tyres re-fitted with some 'bead sealer'. Different tyre pressures accross the front wheels will cause one wheel to lock up ahead of the other. A rolling road test should show if the brakes are working evenly. Jonathan Link to comment Share on other sites More sharing options...
Red SLR Posted March 3, 2004 Share Posted March 3, 2004 I would be supprised if its something to do with the brakes themselves if they have been properly maintained. Its a very light car and even brakes made from cheese would stop it quite well. Has the car ever been set up? If not maybe a trip to a flat floor - check the camber too, unless you have already done so. Link to comment Share on other sites More sharing options...
dino ferrana Posted March 3, 2004 Share Posted March 3, 2004 Is you X-FLow Live axle YW? The rear brakes are pretty terrible in the LA application and you may find the fronts are locking but the rears are not doing a great deal! Link to comment Share on other sites More sharing options...
YW Sin Posted March 3, 2004 Author Share Posted March 3, 2004 Yep, it is a Live Axle car and I do often get a feelig that rear brakes are doing bugger-all! What could be the solution?? Link to comment Share on other sites More sharing options...
Joe 90 Posted March 3, 2004 Share Posted March 3, 2004 If it's always the front left that locks up but it doesn't pull, I would be suspicious of the corner weights. The front left might not be carrying as much weight as the front right. Back on the road and now at 100,421 miles. Photos here Link to comment Share on other sites More sharing options...
Martin H Posted March 3, 2004 Share Posted March 3, 2004 Re. rear brakes, when did you last adjust them? Mine used to feel as if there was no bite on the road (track was fine, once the front brakes had warmed up), until I realised that the rears didn't self-adjust. Once I got that sorted it felt much better on the road. Link to comment Share on other sites More sharing options...
charlie_pank Posted March 3, 2004 Share Posted March 3, 2004 If you are managing to lock a wheel, then you have no problem with the force being exerted on the brake pad on that wheel, the fact that it locks before the other one suggests there's something wrong with the one that doesn't lock: different corner weight seized caliper leaking slave cylinder air bubble in caliper blockage in brake line suspension geometry Have you established whether the brake pedal exerts any force on this wheel at all? There may also be issues with your front/rear bias, but I would be more immediately concerned with the left/right bias you seem to have - after all in the dry the front does about 70% of the braking. I would start by jacking up the offending (ie non-locking) wheel and spinning it (you may need a friend at this point!), then applying the brake to see if it has any effect, then work back from there... Link to comment Share on other sites More sharing options...
robbieclark Posted March 3, 2004 Share Posted March 3, 2004 I find that the sensation of acceleration & deceleration is much reduced in my seven compared to my old tin top (integrale evo 1), I think it's something to do with reduced body movement and momentum/inertia , but side by side comparison shows the seven to accel and deccel harder. Live axle x-flow with 032R and green stuff pads. Link to comment Share on other sites More sharing options...
KenEvans Posted March 3, 2004 Share Posted March 3, 2004 My left front used to lock up very earlier before I had the car corner-weighted, it's the first thing I'd look at in future. Once corner weighted the car was far better balanced under braking with any locking being a function of differential in surfaces rather than weight. Incidentally, with a passenger I now find the right front locks first! Ken Link to comment Share on other sites More sharing options...
YW Sin Posted March 3, 2004 Author Share Posted March 3, 2004 True, about the passenger. I have noticed that the brake seems to work a lot more evenly with a large passenger next to me! The rear brakes has been adjusted just a few days ago before installing the new tires. So they should be OK. Currently I am currinig on 185/70/13 tires... perhaps they are a bit too narrow for 1.7 X-flow ? Link to comment Share on other sites More sharing options...
Anthony Posted March 3, 2004 Share Posted March 3, 2004 Hi 185's should be fine on a mild tune x-flow. Suggest wider tyres not really necessary until c.200 mark. Although I appreciate everyone is entitled to their own view on this ! Good idea to get the one which is leaking checked though Link to comment Share on other sites More sharing options...
stevefoster Posted March 3, 2004 Share Posted March 3, 2004 Is it a big brake on the fronts car? If not I suggest you start there. The tyres do need a couple of hundred miles to scrub in. The current UK weather conditions are too cold for awesome performance from the tyres. Pads make a difference. Green stuff for cold road use perhaps. Something more track / race oriented for track. I have big brakes on the front and Ferodo race pads. Awesome on track when hot with slicks. Ok on the road. Locking up on one front. Suspect corner weights. Even after corner weighting I have to tune the front dampers to circuits. i.e. front right would lock at Druids. Adjust for a little more weight on that wheel. Sorted. Not road or track is flat of course..... Hants (North) and Berkshire Area club site here My racing info site here Link to comment Share on other sites More sharing options...
RayL Posted March 3, 2004 Share Posted March 3, 2004 I will have my 1.8ss in Paris in 4 weeks time, perhaps if you compared it against another you may not find it so bad Link to comment Share on other sites More sharing options...
YW Sin Posted March 3, 2004 Author Share Posted March 3, 2004 RayL, Send me an e-mail before getting here. We could meet up Just came back from a late night spin. Tonight is a bit warmer than yesterday and must say, I can feel definite improvements. Gone are the enthusiastic fish tailing under power and it even stops reasonably though I still won't call it jaw dropping. Yoko A021 certainly feels a lot more surefooted especially around long bends and I am looking forward to take the car to a more challenging roads with much warmer weather. Also I have to test the tires on wet as it was the main reason I have chosen this particular tire. I have also realized that I must learn how to keep pressing the brake just before the locking point. A very classical and technical way of stopping a car without a servo I guess but I am looking forward to master it. By the way how do you add weights on the corner ? Link to comment Share on other sites More sharing options...
Graham Perry Posted March 4, 2004 Share Posted March 4, 2004 Why not put the car on a rolling road brake tester at a garage to see if you have a left to right brake imbalance. Presumaby you have these in France ? Most garages will happily do that here for a few quid, without having a full MOT test Link to comment Share on other sites More sharing options...
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