Forum Home / Ask the Experts! / Tyres!!!!

14/12/2008 22:16:48
meredith1
Hi Guys I', ve tried to make my midget go faster and when my kids get their 5 speed box this winter mechanically we could be close. I have watched the progress of others with track day tyres and have been looking at Dunlop D83J and Yokohama A048 soft compound to try and stop some of the ballerina moves on exit to corners which my current road legal tyres produce!!!! Any suggestions for make/compound or suppliers????:confused:
15/12/2008 12:36:20
gavinsmith
Hi Roger, I don't use them (yet), but my understanding is that the Yoko A048s are superb. I plan to go for these for my BGT (the yellow job you shared a garage with at Donington) when I wear out my existing Yoko A539s. I don't know about the Dunlops, I'm afraid, but there may be others with experience of them. Someone like Joe Philips, who races a B, will know more about the compounds and what would be best for you. I'm sure the soft compound would give the most grip, but will obviously wear more quickly, so you'll have to weigh up costs and benefits. One option I'm thinking about is to get another set of wheels with the 048s on for the track (and getting to and from the track, as I don't have room to lug a spare set of wheels with me) and keep my A539s for the road, to stop the 048s wearing out too rapidly. It depends a bit on how 'enthusiastic' your normal road driving is, I suppose;). Hope to see you on track again next year - I'm certainly planning to do Silverstone and Cadwell of the ones posted so far, and might try to get to Snetterton as well. Gavin
15/12/2008 13:35:40
fishert
I've no experience with Dunlop but currently use 048r (medium compound - because soft was not available at the time). For trackdays they have lasted well & give good grip. May take a lap or two to get to good grip levels but once there maintains a consistant level unless you start to over drive. You may find that softs won't be durable enough - fine for sprints for short sharp bursts. Did find with using a set of 32r for several years that with numerous heat cycles the rubber got harder and therefore took longer to get heat into them. Have had experience with Toyo 888 but not on this car, and they differ from 048s as they do seem to give a consistance grip level over a number of laps
15/12/2008 17:42:55
JP12
I am not sure that the D83J is the best Dunlop tyre for track use, I thought it was more of a rally tyre but I stand to be corrected. If you want a Dunlop tyre look at the DZ03G or D01J tyre. I used an old style DJ series tyre a few years ago and I have to say I think it was really good. Ultimate grip was probably the same as the A048 but it gave up grip at the limit a little slower. I have used the A048 in M and S compounds and for track day use I would recommend the M. A track day is the equivalent [FONT=Verdana]of doing 4 race meetings in a normal championship so you will be replacing tyres far more often if you decide to use the soft compound. If you are easy on your tyres, and use the medium compound, I would hope that you could get through an MGoT season with one set.[/FONT] Have you had a look at the Toyo R888? I don't know what size you need but generally they are a bit cheaper than the A048. Even if they're not quite as good, does it really matter that much on a track day? Also, as Tamsin said, they do need a bit of heat in them to generate good grip levels, so don't go hooning it out of the pit lane and attacking the first corner like you are in the top ten shoot out:D . This takes a lot of restraint if you are following someone that you would like to keep up with, although clearly not racing;) .Optimum tyre pressures are also quite different from standard road tyres, but if I am at the track day I am happy to help or you can borrow my pyrometer. Tamsin, Have you been racing a Golf GTi this year? Joe
15/12/2008 18:59:58
fishert
I would like to correct my previous message about toyo 888s (GG compound) in so much as that they did NOT seem to give a consistant grip level over a number of laps. First couple of laps good then grip level tails off (on initial turn in but this knowledge is based on fwd). But tyre wear is good. But maybe it depends on driving style and the tyre construction Joe I have raced twice this year, in James mk1 gti as he's been racing this year with it in TTRS (toyo tyres racing saloons) including a race at Spa in October. We did MGCC Silverstone 2 driver enduro in it but it expired before it was my turn. Then we did a 2 races at Brands in November (handicap-allcomers). James did first race then I did 2nd race. Getting the midget prepped to do a bit of racing in that for the coming year, Silverstone enduro as a starter & be a bit more in keeping!. I see you've competed in Peter Best Ins Challenge & Swinging sixties. I'm struggling to find a championship to race the K powered midget in. Did email Maggie Y about the committee thoughts about allowing the car, as I read in the latest safety fast that a K powered MGB was allowed, but not heard back. Would you know what the organisers thoughts are on these matters (non original engine). Not sure if we have been at the same trackdays, (as this year we only did Bedford) therefore do you know much about my car. Hopefull will try to do more trackdays this coming year
15/12/2008 19:58:31
JP12
[FONT=Arial][SIZE=4][LEFT]Tamsin, The last time that I saw your car was at Silverstone in October '05. I was in the same session as you in the red MGB roadster with the white hardtop and I also noticed your car at Donington the same year. My car has been fully rebuilt since then because the engine was old, the body was poor and it was the worst handling MGB I have ever driven. I am quite glad that it is now a great little car and should be right at the front of the class A pack next year. Below is the latest news that I have been given about the use of the K series engine in the PBIC, but it doesn't mention its use in a midget. Having said that I can't see why any competitors would have a problem with a K powered midget as long as its lap speed is comparable with other class C cars. [B][/B] [B][I]Possible 2009 Rule Changes for Peter Best Insurance Championship[/I][/B] [B][/B] [/LEFT] [/SIZE][/FONT][FONT=Arial][SIZE=3][LEFT][I][B]K Series Engined Cars in Class C[/B][/I][/LEFT] [/SIZE][/FONT][FONT=Arial][SIZE=3][LEFT][I]2008 has seen several cars run with 4 cylinder K series engines in class C and there are no proper[/I] [I]regulations written at this time.[/I] [I]The use of the K series in an MGB has not been a disaster as some forecast after it's somewhat [/I][I]controversial arrival, indeed it has done a significant amount in raising the awareness of the [/I][I]championship both in and outside the MGCC and it would be good to see its continued presence.[/I] [I]These cars will continue to develop and there is a good possibility of one or two more joining us [/I][I]along with a MG ZS or two.[/I] [I]To make it fair and so everyone knows what is permitted it is proposed to formalise things along[/I] [I]the following lines:-[/I][/LEFT] [/SIZE][/FONT][FONT=Arial][SIZE=3][LEFT][I]Any car originally fitted with a 4 cylinder K series may run at up to 1800cc. MGB may run 4 [/I][I]cylinder K series.[/I] [I]Cylinder heads may be VVC or Motor sport variant but may not be modified. Port sizes at [/I][I]the manifold face could be specified – 36mm is the factory maximum for VVC/VHPD.[/I] [I]All valve sizes and shapes to be as VVC/VHPD.31.5mm inlet, 27mm exhaust.[/I] [I]Minimum cylinder head thickness specified.[/I] [I]Standard 1.8 stroke only.[/I] [I]Standard crank only.[/I] [I]Cams to be defined – probably VHPD spec at 10.2mm lift and 280° duration. Timings 34-[/I] [I]66-68-32. PTP part number may be quote. Lifters free.[/I] [I]Induction and exhaust are free except for compliance with MSA regulations on catalysts.[/I] [I]Engine management free. .Carburation free.[/I] [I]Weight limits subject to continuous review with min 7 days notification of changes.[/I][/LEFT] [/SIZE][/FONT][FONT=Arial][SIZE=3][LEFT][I]The weight agreed for 2008 with the drivers concerned had been based on a power to weight limit [/I][I]of about 200 bhp/ton and discussion of expected performance and the championships reaction to [/I][I]observed on track performance. Again Appendix B contains weight and power info for those[/I] [I]interested.[/I] [/LEFT] [FONT=Arial][SIZE=3][LEFT][I]There is also for the K series cars the possible additional requirement that a rolling road result be [/I][I]lodged with the championship at time of registration and obviously we would set it up such that [/I][I]repeat tests may be asked for during the year, the results of these tests would be passed directly[/I] [I]from the rolling road to the championship. A step further is to state that a data logger must be [/I][I]carried and that the championship gets first access to the data in parc-ferme – this does however [/I][I]place a certain duty on the championship in terms of post race scrutineering.[/I][/LEFT] [/SIZE][/FONT][/SIZE][/FONT]
15/12/2008 20:00:32
JP12
Not sure why the font has gone crazy. It didn't look like that when I wrote it!!
15/12/2008 21:04:36
fishert
Thanks for the extract from regs. Interesting. Will keep an eye on motorsport section MGCC website for regs & make contact with Maggie. You'll have to get your car ready for Bedford to meet again!
16/12/2008 10:38:30
JP12
I think it is highly unlikely that I will make it to Bedford, realistically the car should be ready for Silverstone. I also need to get some new tyres, but if you compete in the CSCC you are restricted to using the Yoko because it's a control tyre.