315 track day tyres
Discussion
doing some due diligence at the moment...
wanting to get some track day tyres for impending delivery of gt2(hopefully today but still nothing), and have been told that dunlop super sport 285's are fat enough to fit on the gt2 which normally take 315's... is this correct?
these dunlops are £130 each as opposed to the michelins which are £293 each!!!
wanting to get some track day tyres for impending delivery of gt2(hopefully today but still nothing), and have been told that dunlop super sport 285's are fat enough to fit on the gt2 which normally take 315's... is this correct?
these dunlops are £130 each as opposed to the michelins which are £293 each!!!
dds1 said:
GT2 tyres were originally going to be 295 rears as standard, they were changed to 315 after Walter Rohrl experienced oversteer at 190mph at the n'ring, you choose! 
>> Edited by dds1 on Friday 8th April 16:08
very good point. so you're saying that losing the 40mm of traction is not going to make too much of a difference to a numpty track novice like myself.
the problem is that 295 's are fitted to 11's (as on my c4s) and the gt2 has 12's.... so i suppose my question is what is the effect of running 295's on 12's???
Buy Corsas then, they are also good on the roads, I use them permanently on my GT2.
I would not consider going down in tyre size to save a few pounds on a £70k car, where a few square inches of tyre rubber is all thats holding you on the road..........oh and your insurer can try and bounce a claim for undersized tyres.
Guy
I'm not sure really. However I suspect that a 285 Dunlop SSR will grip better or as well as a 315 normal road tyre. I would phone Dunlop Motorsport in Birmingham and ask them. They are really helpful I have found.
These Dunlop SSR tyres really are dirt cheap, so it would be great if you could use them.
These Dunlop SSR tyres really are dirt cheap, so it would be great if you could use them.
GuyR said:
And a 235 Toyo will be even cheaper, or how about a 215 Colway Remould.............
This is rear-end grip on a GT2 you are talking about for F**ks sake, get the proper tyres, Cups or Corsas.
Oi Guy, Toyo and Colway? I think Dunlop Motorsport may have something to say about that.
I would have thought that (fundamentally) the SSR would suit the GT2 for all the reasons that the GT3 mob are buying them in great numbers.
However, I accept that as the SSRs aren't quite as wide as the factory tyres, they may (or may not) be ideal.
>> Edited by johnny senna on Friday 8th April 22:55
911nutter said:
very good point. so you're saying that losing the 40mm of traction is not going to make too much of a difference to a numpty track novice like myself.
You dont lose 40mm of traction, your contct patch will stay the same assuming the same tyre pressure, narrower tyres have to be harder due to the additional heat loads they have to deal with. This may not be an issue with a track day tyre which by its nature is softer than a road tyre anyway, so you may find you will get the same grip levels with the narrower tyres but it will wear out significantly faster than the wider tyre.
tony.t said:
Hmmmm,
I would prefer Dunlop DO1J, MPSC, Corsas for track/enthusiastic road, normal road use I would stick with OE tyres or N.
IMHO there is a good reasom SSR are cheap.
Talking to a v helpful guy at Dunlop Msport he said that their aggressive pricing is due to the upsurge in the trackday market worldwide, which they have been following. Their D01J series has always been cheap and they decided to go for it with the SSR's. They are aware that lately a lot of forums are enthusing and they can't make 'em fast enough!
Maybe it will push Pirelli and Michelin to drop their prices as more people switch?
But knowing our luck the manufacturers will all get together and rig them all higher!!!
johnny senna said:
Hmmmm,
I would prefer Dunlop DO1J, MPSC, Corsas for track/enthusiastic road, normal road use I would stick with OE tyres or N.
IMHO there is a good reasom SSR are cheap.
Go on...........
All the comparative tests i have seen seem to show that SSRs do not perform as well as DO1Js MSPC or Corsas in dry track conditions. SSRs are not marketed as road legal track tyres as far as can see so perhaps thats understandable.
I can see no advantage to running SSRs over normal quality N spec road tyres for daily driving street use as their wet performance doesn't appear to be as good, nor is their longevity or refinement.
Someone, IIRC Frank Williams, said that one quarter of your race budget should be spent on tyres. He has a point, why spend £60k on a car £X on performance upgrades only to be passed on track by something a 1/10 of the price because they have better tyres simply to save a few hundred pounds, which as percentage of the running costs of the car, especially on track, is negligible.
As far as I can see no one would buy SSRs if they cost the same as DO1Js MSPCs etc. The only waythey make sense is as a cheap throwaway tyre to have a bit of fun or tution with.
Porsche GT3 said:
Dunlop SSR are going out of production, so next time you change tires you will have to buy 4 new ones istead.
I'm not sure this is true. Dan at Mr Tyre Motorsport said that Dunlop are thinking of bringing the moulds to the UK because the UK track scene is the biggest market for this sort of tyre. This would help keep the price down I guess.
dazren said:
This is rear-end grip on a GT2 you are talking about for F**ks sake, get the proper tyres, Cups or Corsas.
What he said. Proper size, proper tyres. What price do you put on your life?
DAZ
Oh come on, don't be so dramatic.
What defines a proper tyre? Why is a Dunlop SSR not a proper tyre? Whilst I take your point about sizes, I can't see how using a Dunlop SSR suddenly turns your car into a death trap.
tony.t said:
johnny senna said:
tony.t said:
Hmmmm,
I would prefer Dunlop DO1J, MPSC, Corsas for track/enthusiastic road, normal road use I would stick with OE tyres or N.
IMHO there is a good reasom SSR are cheap.
Go on...........
All the comparative tests i have seen seem to show that SSRs do not perform as well as DO1Js MSPC or Corsas in dry track conditions. SSRs are not marketed as road legal track tyres as far as can see so perhaps thats understandable.
I can see no advantage to running SSRs over normal quality N spec road tyres for daily driving street use as their wet performance doesn't appear to be as good, nor is their longevity or refinement.
Someone, IIRC Frank Williams, said that one quarter of your race budget should be spent on tyres. He has a point, why spend £60k on a car £X on performance upgrades only to be passed on track by something a 1/10 of the price because they have better tyres simply to save a few hundred pounds, which as percentage of the running costs of the car, especially on track, is negligible.
As far as I can see no one would buy SSRs if they cost the same as DO1Js MSPCs etc. The only waythey make sense is as a cheap throwaway tyre to have a bit of fun or tution with.
Tony,
I think you are missing the reason why I use these tyres.
They are a comprimise between Michelin Cups or Dunlop D01Js on the one hand and the N rated road tyres on the other, like a Contisport Contacts or whatever.
The SSR will at least make an effort to keep you on the road (or track) in cold wet weather. The Michelin Cups are not known for being good at this, neither are D01Js. So even if the SSR was the same price a Michelin Cup or a Dunlop D01J, there would still be excellent grounds for chosing this tyre.
Then when you rock up at a dry track day, your car will be reasonably quick, somewhere between a car on N rated road tyres and a car using Michelin Cups.
So if like me you don't have a trailer so you can bring 2 sets of tyres to the track, the SSR makes absolutely perfect sense.
Nobody said they are as fast as a Michelin Cup in the dry, the tyre is about comprimise.
Right, I'll start a new thread with some pics of my SSRs after today's track day at Croft.
>> Edited by johnny senna on Saturday 9th April 18:27
Have fitted a set of SSR's to my 520bhp 993gt2. Had corsas before, SSR's superior in damp, wet and cold, more stable on track due to 'straight' tread pattern instead of Corsas S profile, marginally less ultimate grip, but overall very good. Not inferior as some are suggesting, I dont skimp on tyres on my £100k car!
Fxxk all wrong with them, get them on I say!
Fxxk all wrong with them, get them on I say!
johnny senna said:
Oh come on, don't be so dramatic.
What defines a proper tyre? Why is a Dunlop SSR not a proper tyre? Whilst I take your point about sizes, I can't see how using a Dunlop SSR suddenly turns your car into a death trap.
There won't be anything wrong with the tyre, but personally I wouldn't put any tyre on a road going porsche that doesn't have an N number. I don't believe the SSRs have this, although apologies if they do. We all know how insurers aren't really there to pay out, I just wouldn't want to give them a potential excuse to decline a claim.
As for the sizing, my turbo runs a 295 width tyre on an X inch width alloy, GT2s run 315 on an X+1 inch width alloy. I don't believe it is advisable to run a 10mm narrower tyre than I run on a 1 inch wider alloy.
DAZ
(Obviously not a tyre engineer, so may be talking out my a...!)
>> Edited by dazren on Saturday 9th April 19:28
Hi Daz,
The issue of N-rating and insurance is a good point. Perhaps on a 10 year old car like mine the insurer may not mind so much? On a newer car, I would have to say that using N-rated tyres is probably sensible from an insurance point of view.
I may give a list of all my modifications to my insurer. At the moment, they have it down as a 993 RS, Clubsport spec, with a bit more power than standard. I think I will have to send the big list of mods, including the air jacks etc. I will make a point of telling them that my tyres are NOT N rated so if I do crash, they will have to honour my claim (assuming they don't mind the SSRs of course).
The issue of N-rating and insurance is a good point. Perhaps on a 10 year old car like mine the insurer may not mind so much? On a newer car, I would have to say that using N-rated tyres is probably sensible from an insurance point of view.
I may give a list of all my modifications to my insurer. At the moment, they have it down as a 993 RS, Clubsport spec, with a bit more power than standard. I think I will have to send the big list of mods, including the air jacks etc. I will make a point of telling them that my tyres are NOT N rated so if I do crash, they will have to honour my claim (assuming they don't mind the SSRs of course).
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