Guys, last year I did some slaloms here in Germany with my MRS3 Trophy, at first with my daily UHP -tires Michelin Pilot Sport S4, was better than expected, was the quickiest sedan after the lightweight Elises a.s.o. even with these tires... This year, I want to be prepared a bit better, thinking about using semis. With slalom, the problem is to get the tire warm as quick as possible and I would ask if anybody has some experiences what you would recommend. I would use 225/40 R18 cause they are much cheaper than 19" and at least theoretically, a tiny bit lower than 19. I would use Autec wheels, they are very lightweight and cheap and the rim offset ist 45 mm and gives a bit more track wide. I use KW coilovers with adjustable top mounts set up with 2,1° camber. I thought about using Michelin Cup2, Toyo or Yokohama, but would listen to your advices. The tires shouldn´t be suitable at least not only exclusivly for track days, but as told for Slalom to heat up relativly quick without collapsing if I would do an Trackday as well. Thanks for your advices !
We have the same problem with hill climbs, especially as sometimes we are not even allowed to spin the tryes up before the start. The treadwear index gives you an idea of the hardness of the rubber and hence its grip, or rather lack of grip, when cold. Road tyres vary between 180 (AD08R) and upwards. Track tyres (Toyo R888R etc) are quite a lot softer from 80 upwards. Some motorsport approved remoulds such as Maxsport or Extreme are even softer. We also run the lowest pressures that we can get away with - for the megane say 1.7 to 1.9 bar.
Crazy, George, I never read a discussion about this treadwear indicator according to the grip level the tire provides, thanks for it ! It seems as well as the TI isn´t stated for every tire at least on the advertising sites….. what TI is the Michelin Sport Pilot S4? And where do I find the TI-figures from all the Semis? With slalom, I´ve a feeling that a soft tire sidewall is critical independing of the softness of the rubber. In sharp U-turns, once the car understeers, the sidewalls on front are so to say tilting down, on my Sport Pilots the Michelin-lettering was particulary rubbed from this loads. Now I hope with 2° of camber and a higher grip level with Semis the understeering will be fixed. On hillclimbing, your speeds are much higher and the steering angles much lower, so the sidewall can be softer. With 1,7 bars on slalom, I´m worried that the tire will be pulled off the rims….In Germany, it´s called the tire will be "overdriven" if it´s stressed too hard. The Michelin Pilot did collapse after 3 or 4 fast laps on Slalom at least with high temps in summer - understeering like crazy. A buddy of mine did recommend the Toyo R888R, the Federal 595 or the Nakang NS2R or Yoko Advan. What do you think?
Its very difficult to find out the Treadwear Index ratings from websites. On the tyre they are shown in small print on the sidewall near the tread - often next to a couple of other ratings; I have just checked in the garage, the R888R's are Treadwear 100, Traction AA Temperature A and the Michelin PS4's are 320, AA, A. A word of caution is that these ratings seem to be determined by the manufacturer and may not be consistent. In the days when there was greater freedom (pre EU Energy ratings), my Kumho V70A supersoft were a mere 30 and amazing! You are right about pressures - the ones I quoted are for the R888R etc, i.e a road legaltrack tyre - even so 2 degrees plus camber is the norm. for the PS4 about 2.1. Lighter cars using R888R will go down to 1.5 I have no feedback on Federal or Nangkang - Yoko A052 seem very good but the most expensive.
….but the Yoko A052 seems not to be a real Semi, it´s more a UHP tire….What do you think about KumhoV70? I´m owning as well a classic Renault Alpine A 110 what i´m currently rebuilding to use for Slalom/trackdays. The car has 13" wheels, really difficult to source several brands, not just for racing, but as well for occasionally use. Kumho has 205/50-13 and 235/45-13 which would work for me, if I use them for daily should I choose the hardest compound what they are offering and for racing, the softers? The car should be able to be handled as well in rain. Whats your opinion?
A052s are up there with 03Gs and Trofeo R performance wise though. Superb tyre and the cost wad the only thing stopping me using them again
Our experience of A052 is fairly limited - but the cars on which we have seen them, Exige and Imprezza have been super competitive. As for the Kumhos, they were very good in the wet (Clio and DC5). Depending on how many road km you do, you could probably get away with just the soft - I used to drive to events on them and probably do 1,500 km per year - dpeends on how hard you want your road km to be!!
Good morning, just a quick thought for your information - our local hill climb does involve 1st gear corners, so speeds are probably comparable. On a FWD car we rarely get temperature into the rear tyres!
