Discussion
wong said:
Now , what about tyre pressures ?
As low as you dare to go! F1 tyres run with hot pressures of around 17 to 18 psi, limited by safety concerns rather than performance. Increasing pressure above 18 psi simply reduces lateral grip and traction. Obviously you can't go that low with a conventional low profile road tyre because of the much smaller air volume in the tyre. uktrailmonster said:
However, extremely low profile road tyres are purely cosmetic. Touring cars in the late 90's switched from 18" to 19" rims for various reasons, but the 18" were actually quicker. [i]I think high performance road cars generally work best on 17" wheels[/b]. Anything bigger is just for looks.
Interesting.I can think of some cars which I think fall into the category "high performance road cars" which are better on 18s than on 19s, such as M3s and GT3s, but of another car which was positively transformed by going from 17s to 19s.
Folks you're still ignoring that these road based and GT cars you're on about performing better with large rims and low profiles have a vast weight advantage when it comes to traction compared to the F1 car*, hence they can afford to sacrifice longitudinal grip for increased cornering stiffness and ultimately lateral grip.
Iain
- Yes that ignores the aero weight of the car, but the traction comes into its own when accelerating from low speed.
Iain
Kubica said:
flemke said:
but of another car which was positively transformed by going from 17s to 19s.
Yeah but wasn't that mainly to get modern high performance tyres to fit?The original 17" tyres were fine in terms of max speed, but they had a lot more lateral compliance than I wanted, and that was a function of the relatively tall aspect ratio. It is possible to make any tyre of a given aspect ratio more or less laterally stiff (not a lot of lateral stiffness in the tyres on a modern Formula One car), but, other things being equal, the lower the sidewall, the more lateral stiffness.
A high performance car of the late '80s, the F40, had rears that were 335/35/17, so a low ratio was available for a road car nearly two decades ago. The ride quality of that car, however, was considered to be much too harsh.
One of the changes that were made to the '95 GTR race cars was to go to 18" wheels, with a lower AR.
flemke said:
Kubica said:
flemke said:
but of another car which was positively transformed by going from 17s to 19s.
Yeah but wasn't that mainly to get modern high performance tyres to fit?The original 17" tyres were fine in terms of max speed, but they had a lot more lateral compliance than I wanted, and that was a function of the relatively tall aspect ratio. It is possible to make any tyre of a given aspect ratio more or less laterally stiff (not a lot of lateral stiffness in the tyres on a modern Formula One car), but, other things being equal, the lower the sidewall, the more lateral stiffness.
A high performance car of the late '80s, the F40, had rears that were 335/35/17, so a low ratio was available for a road car nearly two decades ago. The ride quality of that car, however, was considered to be much too harsh.
One of the changes that were made to the '95 GTR race cars was to go to 18" wheels, with a lower AR.
BTW, was there any difference in traction when you went from 17" to 19" ? I can't remember without going through all the F1 thread but if you could have had the same spec (Bridgestone?) tyres fitted to your original rims would you have done that instead?
Kubica said:
By high performance I mean softer, stickier, sportier rubber, as distinct from say harder compound, fuel efficient low rolling resistance or long life tyres.
BTW, was there any difference in traction when you went from 17" to 19" ? I can't remember without going through all the F1 thread but if you could have had the same spec (Bridgestone?) tyres fitted to your original rims would you have done that instead?
There is probably more traction with the new tyres, but I'm not sure whether that is because the rears are 345 v 315, or for another reason. The treadwear ratings of the two tyres are about the same, although Michelin and Bridgestone may use different standards of measurement, so the numbers may not be comparable.BTW, was there any difference in traction when you went from 17" to 19" ? I can't remember without going through all the F1 thread but if you could have had the same spec (Bridgestone?) tyres fitted to your original rims would you have done that instead?
What do you mean by "same spec" Bridgestones? Do you mean tyres with identical performance characteristics to the 19", but they just happen to differ cosmetically by being 17"?
flemke said:
There is probably more traction with the new tyres, but I'm not sure whether that is because the rears are 345 v 315, or for another reason. The treadwear ratings of the two tyres are about the same, although Michelin and Bridgestone may use different standards of measurement, so the numbers may not be comparable.
I've been fortunate enough to test the 2 brands flashship (at the time) 'max performance summer' tyres back to back, Pilot sports VS s02.While I keep meaning to write something up anecdotally for my site www.tyrereviews.co.uk I did find the Michelins to be able to start and stop much better than the S02s, feeling strong under traction exercises where as the S02s to be more capable under the lateral loads in the corners.
This could of course have been to do with unlimited ouside factors as it was by no means a scientific test; side wall stiffness, tyre pressures not being identical etc but I found it to be an interesting experience.
Again, anecdotally, I once moved from a 225 section to 255 section rear (S02) and couldn't notice any traction, the rears still span up as easily as they had in 1st and 2nd.
Kubica said:
flemke said:
What do you mean by "same spec" Bridgestones? Do you mean tyres with identical performance characteristics to the 19", but they just happen to differ cosmetically by being 17"?
Yeah exactly that, same brand and model just different size.If they were identical in all performance respects but only looked different, I'd rather have the high-sidewall style of the originals.
Edited by flemke on Wednesday 22 August 00:01
jon- said:
flemke said:
There is probably more traction with the new tyres, but I'm not sure whether that is because the rears are 345 v 315, or for another reason. The treadwear ratings of the two tyres are about the same, although Michelin and Bridgestone may use different standards of measurement, so the numbers may not be comparable.
I've been fortunate enough to test the 2 brands flashship (at the time) 'max performance summer' tyres back to back, Pilot sports VS s02.While I keep meaning to write something up anecdotally for my site www.tyrereviews.co.uk I did find the Michelins to be able to start and stop much better than the S02s, feeling strong under traction exercises where as the S02s to be more capable under the lateral loads in the corners.
This could of course have been to do with unlimited ouside factors as it was by no means a scientific test; side wall stiffness, tyre pressures not being identical etc but I found it to be an interesting experience.
Again, anecdotally, I once moved from a 225 section to 255 section rear (S02) and couldn't notice any traction, the rears still span up as easily as they had in 1st and 2nd.
I'd expect that what you tested would not be analogous to the above, although the two firms' basic design philosophies could be the same across both.
Cheers.
Kubica said:
wong said:
Thanks for all the replies...interesting.
I think caterham recommend 13 inch wheels as the ideal size for track use as well.
Now , what about tyre pressures ?
I think it's 14" with 15" being an option?I think caterham recommend 13 inch wheels as the ideal size for track use as well.
Now , what about tyre pressures ?
flemke said:
Bridgestone "Scuderia", which was designed specifically for the Enzo
Again, anecdotally but I've heard on the rumour mill more than once that one of the first, and best upgrades Enzo owners can make is ditching the 'stones and throwing on a set of Pirelli, not sure if you've heard this?Redlake27 said:
They are 13" because it gives space for a bigger logo.
Excellent point James!jon- said:
flemke said:
Bridgestone "Scuderia", which was designed specifically for the Enzo
Again, anecdotally but I've heard on the rumour mill more than once that one of the first, and best upgrades Enzo owners can make is ditching the 'stones and throwing on a set of Pirelli, not sure if you've heard this?One of the reasons that I chose the Bridgestones is that I expect them to be in production for many years.
I know a chap who does tyre testing for Bridgestone, and who was involved in developing the Enzo tyres. (He's not a corporate drone; he's an independent, and is one of absolutely fastest guys around the 'ring in VLN, so he knows what he's talking about). He told me that it's a good tyre, which was reassurance enough for me.
flemke said:
I wouldn't know about that, although I'd be happy to try out the Pirellis.
One of the reasons that I chose the Bridgestones is that I expect them to be in production for many years.
I know a chap who does tyre testing for Bridgestone, and who was involved in developing the Enzo tyres. (He's not a corporate drone; he's an independent, and is one of absolutely fastest guys around the 'ring in VLN, so he knows what he's talking about). He told me that it's a good tyre, which was reassurance enough for me.
And I'd kill for some feedback if you ever do change tyres One of the reasons that I chose the Bridgestones is that I expect them to be in production for many years.
I know a chap who does tyre testing for Bridgestone, and who was involved in developing the Enzo tyres. (He's not a corporate drone; he's an independent, and is one of absolutely fastest guys around the 'ring in VLN, so he knows what he's talking about). He told me that it's a good tyre, which was reassurance enough for me.
After slowly cranking my long term memory it's a little rusty these days!) I believe my above statement was incorrect and the comments were made about the Bridgestones on the MC12, I'm not sure if that's the same tyre as used on the Enzo.
jon- said:
flemke said:
I wouldn't know about that, although I'd be happy to try out the Pirellis.
One of the reasons that I chose the Bridgestones is that I expect them to be in production for many years.
I know a chap who does tyre testing for Bridgestone, and who was involved in developing the Enzo tyres. (He's not a corporate drone; he's an independent, and is one of absolutely fastest guys around the 'ring in VLN, so he knows what he's talking about). He told me that it's a good tyre, which was reassurance enough for me.
And I'd kill for some feedback if you ever do change tyres One of the reasons that I chose the Bridgestones is that I expect them to be in production for many years.
I know a chap who does tyre testing for Bridgestone, and who was involved in developing the Enzo tyres. (He's not a corporate drone; he's an independent, and is one of absolutely fastest guys around the 'ring in VLN, so he knows what he's talking about). He told me that it's a good tyre, which was reassurance enough for me.
After slowly cranking my long term memory it's a little rusty these days!) I believe my above statement was incorrect and the comments were made about the Bridgestones on the MC12, I'm not sure if that's the same tyre as used on the Enzo.
It was never clear to me whether Pirelli were going to continue to make those tyres, or they just did a few sets for the MC12.
flemke said:
jon- said:
flemke said:
I wouldn't know about that, although I'd be happy to try out the Pirellis.
One of the reasons that I chose the Bridgestones is that I expect them to be in production for many years.
I know a chap who does tyre testing for Bridgestone, and who was involved in developing the Enzo tyres. (He's not a corporate drone; he's an independent, and is one of absolutely fastest guys around the 'ring in VLN, so he knows what he's talking about). He told me that it's a good tyre, which was reassurance enough for me.
And I'd kill for some feedback if you ever do change tyres One of the reasons that I chose the Bridgestones is that I expect them to be in production for many years.
I know a chap who does tyre testing for Bridgestone, and who was involved in developing the Enzo tyres. (He's not a corporate drone; he's an independent, and is one of absolutely fastest guys around the 'ring in VLN, so he knows what he's talking about). He told me that it's a good tyre, which was reassurance enough for me.
After slowly cranking my long term memory it's a little rusty these days!) I believe my above statement was incorrect and the comments were made about the Bridgestones on the MC12, I'm not sure if that's the same tyre as used on the Enzo.
It was never clear to me whether Pirelli were going to continue to make those tyres, or they just did a few sets for the MC12.
Jon
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