MadManMike Posted September 1, 2013 Author Report Share Posted September 1, 2013 Pardon my ignorance, but what went wrong there? Other than some slight drift? Quote Link to comment Share on other sites More sharing options...
Pashley26 Posted September 1, 2013 Report Share Posted September 1, 2013 Drifting is NOT quick. Shit tires and no grip losing Alex his competetive season points is the connection you are looking for. Gutted for you. Quote Link to comment Share on other sites More sharing options...
Greetings Posted September 1, 2013 Report Share Posted September 1, 2013 Pretty much what Jardo said. The car was equipped with 1 metre of fresh Michelin racing slick rubber. The car should be hitting up to 1.4g in the corners on that surface and braking just as well. In the mean time, those tyres were probably delivering no more than 0.9g which is equivalent to an ultra high performance tyre. So I was experiencing understeer in corner entry and mid corner, oversteer on exit and snap oversteer on the quick bits. This goes in contrast with the typical behaviour of racing slicks which is like driving on rails. Quote Link to comment Share on other sites More sharing options...
mboon Posted September 2, 2013 Report Share Posted September 2, 2013 I have had a couple E36 M3's. Evo and nn Evo. Loved them both. Great cars Quote Link to comment Share on other sites More sharing options...
MadManMike Posted September 2, 2013 Author Report Share Posted September 2, 2013 That makes sense, but from your post I was expecting an epic crash rather than some drifting. 1 Quote Link to comment Share on other sites More sharing options...
Greetings Posted September 2, 2013 Report Share Posted September 2, 2013 That makes sense, but from your post I was expecting an epic crash rather than some drifting. Haha, sometimes the worst things can be pretty undramatic though Quote Link to comment Share on other sites More sharing options...
AdamR28 Posted September 2, 2013 Report Share Posted September 2, 2013 Seems weird. Nothing else changed on the car other than a fresh set of tyres? Quote Link to comment Share on other sites More sharing options...
forteh Posted September 2, 2013 Report Share Posted September 2, 2013 Could it be that your normal suspension setup was too stiff to make these tyres work and you perhaps needed more roll or something? Sort of like my heatsink yellows not working once they had less than 2mm material left, not enough compression to get them to grip if you know what I mean? Although if you have run those tyres ok in the past with the same setup then something must be amiss Quote Link to comment Share on other sites More sharing options...
MadManMike Posted September 2, 2013 Author Report Share Posted September 2, 2013 I need some ultra strong adhesive pads, similar to those used to stick car badges on. What would you guys suggest? Quote Link to comment Share on other sites More sharing options...
RobinJI Posted September 2, 2013 Report Share Posted September 2, 2013 Any decent auto-factor will sell 'trim tape' which is supper sticky double sided foam tape. It's what you use to attach bump strips, badges etc. A small bit of it should do the trick. Or the little pads for attaching numberplates seem to be decent, when someone ripped the rear plate of my MX-5 it took a fair chunk of the plastic it was stuck too off with it! Quote Link to comment Share on other sites More sharing options...
MadManMike Posted September 2, 2013 Author Report Share Posted September 2, 2013 Yeah having a read on various places, the Halfords stuff is apparently good... I was assuming it wouldn't be. £2.09, sounds good to me! Quote Link to comment Share on other sites More sharing options...
RobinJI Posted September 2, 2013 Report Share Posted September 2, 2013 Yeah, Halfords ones have always done the trick for me. Even come with a little 'surface prep' wipe thing to make sure everything's clean and grease free. (Meant to say, they're what ripped the plastic off on my MX-5.) Quote Link to comment Share on other sites More sharing options...
Greetings Posted September 2, 2013 Report Share Posted September 2, 2013 Seems weird. Nothing else changed on the car other than a fresh set of tyres? There was one change - arb was mounted to the strut, not wishbone. This gives less roll and although I doubt this would contribute on that surface, theoretically that induces understeer. But the lack of grip was too apparent both on the front and rear axle for it to just be a setup issue. Either way I'll be softening the front arb. Could it be that your normal suspension setup was too stiff to make these tyres work and you perhaps needed more roll or something? Sort of like my heatsink yellows not working once they had less than 2mm material left, not enough compression to get them to grip if you know what I mean? Although if you have run those tyres ok in the past with the same setup then something must be amiss Although stiff, that suspension is very compliant. The high speed damping on that kit is bang on for rough surfaces and these weren't rough (well, just a bit). As for the roll, if I could blame the setup it would be that. But I find it highly unlikely considering that all I did was mount the arb's the way they should be mounted in the M3. My friend has a theory about these tyres having undergone some very bad heat cycles - perhaps they were overheated, then rapidly cooled before they got removed from the previous car they were on (GT3 Cup). Either way, I've ordered a very accurate Longacre manometer and a laser pyrometer to better understand tyres, pressures and temperatures. And for the future, I'll be ordering my tyres from people who make a living out of selling 2nd hand slicks, not a friend who's part of a racing team and visits all the mayor events in Europe. The former have reliable suppliers, knowledge and a reputation to upkeep, the latter doesn't really know what he's getting. Quote Link to comment Share on other sites More sharing options...
forteh Posted September 3, 2013 Report Share Posted September 3, 2013 Ah, didn't realise they were previously cycled, would explain a lot Laser pyrometers/thermometers are ace. Want to know how hot your manifold is? - zap it! Want to know how hot your sump is? - zap it! Want to tease the cat and make it run around in circles for hours on end? - zap it! Use mine for ridiculous amounts of things that you never realised it would be useful for; I bought mine for checking surface temperatures in the reptile tanks, it has since been used to check for slab temperature on the patio, relative temperature of different body parts, temperature of children (my step kids - not random ones on the street!), crank case temperature in the oven when pressing in new main bearings (more accurate than the spit on it and if it bubbles and rolls its right). Love it, best 15 quid I spent at maplins 2 Quote Link to comment Share on other sites More sharing options...
AdamR28 Posted September 3, 2013 Report Share Posted September 3, 2013 Ah, didn't realise they were previously cycled, would explain a lot Yeah, especially if there wasn't a lot of rubber left on them. Had this issue on a track day recently, below a certain amount of tread depth the tyres wouldn't hold any heat and it was suuuuper slippery. Quote Link to comment Share on other sites More sharing options...
N.Wood Posted September 3, 2013 Report Share Posted September 3, 2013 They must have been getting rid of them for a reason? Quote Link to comment Share on other sites More sharing options...
AdamR28 Posted September 3, 2013 Report Share Posted September 3, 2013 Some race teams will bin tyres after one session, since that's when they've given the best lap times. Others will run them down to the wear markers. The first ones are ok, the second ones are only fit for skidding about on or the bin... They also degrade with UV light, so old tyres sat around for a while are crap too. As Alex eluded to, if you have a reliable source then buying used tyres is fine, but I guess there's always someone out there trying to flog naff stuff Quote Link to comment Share on other sites More sharing options...
Greetings Posted September 3, 2013 Report Share Posted September 3, 2013 ^ Exactly temperature of children (my step kids - not random ones on the street!), That would probably be highly illegal But yeah, the possibilities seem endless. When I got my first electronic scales I would measure how much a sip of tea weighed. Now I can see myself measuring tea temperature without having to check whether it's cool enough to drink. Life will be so much easier. Mr. Bearded Dragon is probably going to enjoy it too. Quote Link to comment Share on other sites More sharing options...
RobinJI Posted September 3, 2013 Report Share Posted September 3, 2013 They are ace, very useful, should really help you dial in the geometry. If you're comparing tyre temperatures to those you read elseware, beware that race-teams will usually measure the temperature about 1mm under the surface with a probe, rather than a surface temperature, so expect yours to be a bit lower as the surface will have cooled a touch by the time you've pulled up and measured them. As the others have said, and you seem well aware, the tyres were likely just duds. Although the ARB won't have helped. The car does look like it lacks compliance a bit, going a bit softer even on a smooth surface probably wouldn't hurt and should make it less skittish. 1 Quote Link to comment Share on other sites More sharing options...
Greetings Posted September 4, 2013 Report Share Posted September 4, 2013 Is there any universal knowldege when it comes to tyre pressures, temps and wear? I bet technical literature is hard to find and probably way too complex but if you have a link, I'd be grateful. From what I remember you're part of a uni racing team? Essentially what I'd like to know is what my goal should be when it comes to temperatures and pressures after the run because those are the ones I can measure. Currently the only problem I have noticed is very uneven wear. Excessive wear occurs on the outside 1cm of thread. The middle is lightly worn and the inside is somewhere in between the two. This is obviously due to low pressures but I was also told that Dunlops I use come off cars which run 5-9 degrees negative camber. This counters the weak sidewalls which result in ridiculously low weight - the reason I enjoy running these. I have yet to try a set on higher pressures to see how much I can counter tyre roll and the wear problem but I wonder whether that should be my goal when setting things up. Quote Link to comment Share on other sites More sharing options...
AdamR28 Posted September 4, 2013 Report Share Posted September 4, 2013 Set the pressures using temperature - it should be around 80 degrees in use (realistically with an IR sensor and after bringing the car in you'll only see 30-40 though), with a ~10-15 degree split across the tyre, with the inside edge being hotter (example: inside edge 40, middle 35, outer edge 30). The centre of the tread should ideally be bang inbetween the inner and outer edge. Tweak pressures until this is the case. Sounds like you have been underinflating the tyres a lot at the moment, and more pressure should help support the tyre and reduce the outside edge wear. You might need to soften the car up now though, as more air in the tyres will add rate to the (already looking pretty stiff IMO) suspension system... Quote Link to comment Share on other sites More sharing options...
Pete.M Posted September 4, 2013 Report Share Posted September 4, 2013 Perhaps those lightweight dunlops are not really suitable for that style of racing. What tyre regulations do you have to follow? Quote Link to comment Share on other sites More sharing options...
Greetings Posted September 4, 2013 Report Share Posted September 4, 2013 (edited) No regulations whatsoever, it's an open class. In terms of the way they wear, and the car setup they are probably unsuitable as you say. In terms of grip and unsprung weight they offer, they are brilliant. Adam, this sounds very much like what I got on Saturday when I used my friend's pyrometer. I think I got a maximum of 40/45 on the front with a 10 degree spread and 60 on the rear with a similar spread. You say the tyres quickly cool down which I accept as a fact but I therefore wonder what the front tyre temps on my competitor's Megane must be when he's getting 95C after a run Would increasing pressures not make the inside wear a bit more? Because I must avoid that based on the pic below. These are my last 2nd hand Dunlops after about 100 miles of special stage: They still performed brilliantly in this condition - on the last run I used them on, I hit 1.4g lateral. Edit: the tyres above were run at 2bar hot. Apparently not enough. Edited September 4, 2013 by Greetings Quote Link to comment Share on other sites More sharing options...
AdamR28 Posted September 4, 2013 Report Share Posted September 4, 2013 I therefore wonder what the front tyre temps on my competitor's Megane must be when he's getting 95C after a run . Way too hot On the photo above, the left hand side of the screen is the outside edge of the tyre, is that correct? 2 bar hot sounds fairly low, I'm running about 1.5bar on a 700kg (with occupants etc) car with 'soft sidewall' tyres and just over 2 bar on 970kg with Federals. Guessing your car is nearer 1300kg? Seems weird that the temp spread is even at only 2 bar Guess the tyres are really low profile? Quote Link to comment Share on other sites More sharing options...
MadManMike Posted September 4, 2013 Author Report Share Posted September 4, 2013 Two questions, relating to interior pimping... 1) Is there a decent product to use to clean seats? All of mine are pretty stained now from having leaking windows / clumsy drinkers in the car. A full valet around here is about £50, so if I could do it myself I'd rather. 2) My drivers seat is ripped and I'm too skint / lazy to buy a different seat to fit. Is there a good way to repair it? Quote Link to comment Share on other sites More sharing options...
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