924Srr27l
New member
PSH Hi Roger
This is the first set that I've had, I'm usually a 'Goodyear' man but alas they are no longer available in my size for a symmetrical directional pattern. These have been on the car for nearly two years (12,000 miles) with no real signs of wear, they are brand new in the picture. The fronts have worn but that's my fault for not getting the geometry sorted quick enough after the rebuild, in my defence I had my son's wedding to go to in Devon which took priority.
Pete
Ok, so that's quite impressive then with all that Torque! as the Compound or treadwear number as the America Rating is low / soft @ 140
A toyo R888 Track tyre is Rating 100 and as a comparison my current Michelin Pilot Sport 3's are rating 320.
The bridgestone and Michelin constructions and compounds are like chalk and cheese,
I've always preferred for road use a Michelin Tyre because it has a Soft thinner Sidewall and a harder compound which is essential
when a soft sidewall generates so much heat, otherwise the tyre would wear excessively. I've found this set up also allows for a stiffer chassis (Higher damper bump & rebound & Bigger ARB's) and then let all the give, compliance & rock and roll occur in the tyres, a bit like F1 to a degree (Without trying to digress too much) very stiff suspension & minimal travel but a big sidewall profile on 13" Rims.
F1 tested 18" low profile tyres and they were a nightmare to drive, and 12+ seconds a lap slower! (Another related discussion on profiles!)
A Bridgestone construction has a thicker stiffer sidewall which copes much better with HEAT and hence they can reduce the compound
grade and make the Coefficient Of Friction higher with a softer shore & treadwear rating but because the sidewall is stiffer the suspension settings could need softening otherwise stiff everywhere is too much for the road and several characteristics occur.
My current Michelin set up is very good, but I like many desire to constantly develop and test new things I'm keen to try a Stiffer sidewall Bridgestone with a softer compound.
Especially after a run in the car a couple of weeks ago when I had pumped the tyres up to 40psi over winter to avoid flatting them. I went out for an hour run in the pi$$ing rain in North wales and couldn't be arsed to reduce the pressures, being fully aware of this and driving more gingerly than normal, however the car felt good, so I pushed more and found it was still had impressive traction off the line and no loss of cornering grip either when pushed (which I was expecting) should of been the case as previously I'd been running 26psi! which is the ballpark for a lightweight car @ 1110kg. (Inc driver & Fuel)
Tyre Pressure is usually dependent on load / weight and the tyre width & profile. hence why Commercial vehicles are up in the 45 - 60psi+range and the pesky MX5 and Lotus Elise etc...are down in the 26's.
But there are exceptions to this rule when Wide and / or higher profile tyres on some heavy cars like big jags are not that high because the section width and volume evenly distributes the pressure per square inch.
EG:
A Jaguar XKR V8 4.0Turbo 1998 model has 245 & 255 wide tyres with pressures 32F & 29R psi
A ford Fiesta 1.25L 1999 165/70/13 is 30F 26R psi !
If anyone has any part worn So2's in 205/55/16 i'm after a set of 4 to test? (they will be getting an application of Tyre Softner)
or Kumho V70A's ?
R