The fastest closed wheel racecar

[ronbros]

I think that the Toyota Eagle MkIII still holds the Daytona road course record.

and it was a 4-four cylinder

[ringle]

I wonder what the ground-effects Group C cars could do with modern rubber.

Is this a fair assessment? Are the tires not a part of the car as a whole? If we are able to pick and choose the components of a modern car and apply them to an older car than why not take the best features of other cars and post-apply them to a car of a different era?

This would allow us to take all the best elements of every era...say, ground effects, turbo-charging, movable aero-parts/wings, second brake pedal, six wheels, witches'-brew fuel, nose dampers, KERS, Nitrous Oxide, etc. and make a super-hybrid racer!

It would be fun, but would it be a fair comparison?

[clutch-monkey]

it is fair imo, tires are a consumable you chew through them and change them frequently anyway, and whilst vital for performance it doesn't alter the actual car in any way.

[henk4]

it is fair imo, tires are a consumablel you chew through them and change them frequently anyway, and whilst vital for performance it doesn't alter the actual car in any way.

not only that but if you would try to race it with period rubber (made many years ago) you might find that the life of rubber is not eternal...

[LeonOfTheDead]

I'll repeat here the same point I posted don't know where.
Tires, especially high performance and racing tires, are designed specifically for their applications. Remember the days when Bridgestone tires (iirc) were perfect on Ferrari F1 cars but horrible on the other second tier cars?
I don't know the figures for sports cars, as that's what we are talking about, but let me carry on the F1 example.
Right now F1 car can achieve up to 5g acceleration (lateral and backward), therefore tires must be designed to comply with this requirement, among others.
Older F1 cars with perhaps twice (or few less) the power were not capable of such accelerations, and therefore either were the tires.
It could be discussed if these acceleration figures are achieved mainly thanks to what, the design of the car or the tires themselves, still, putting modern F1 tires in an older F1 car with active suspensions, turbo and other stuff would almost surely result in a better performance, but I'd bet the car wouldn't be using at 100% the tires.
As a stupid example, if the car can develop say only 2,5 g of maximum acceleration during corners, it may even happen that the tires won't reach the best temperature to work at.
A specific setup and tuning of the car would be necessary to say the least, regardless of which car we are talking about.

Back to close wheel cars, back in 2005 I was at the Mugello track for a round of the Italian GT Championship.
A friend of my father, orthopedic surgeon Piergiuseppe Perazzini, was driving at that time a Maserati MC12 GT1, mainly against the ex-Prodrive Ferrari 550 GTS.
On the wet track during qualifying, the margin of the MC12 was enormous, there just wasn't a comparison. Still on Sunday the track got a bit drier. They didn't change the setup of the car as it was reported that it would have rain again.
It didn't, and while the track was still humid, the full wet setup of the MC12 wasn't able to keep the tires' temperature at decent levels, and they were loosing about 2 seconds per lap, while the 550 GTS was flying away.
It didn't help to have a mid engine layout in this particular situation (see: with the wrong setup), as even if the weight bias in racing cars is generally achieved trough the ballast, that's only refer to the static effect of the gravity, not considering the dynamic effect when the car is braking, cornering and so on. digressing.

[henk4]

a similar story this, but perhaps more illustrative.
The Maserati 250F in its days used to be car that could be wonderfully powerslided, as it was a perfect combination of tyres and a flexible chassis. Trying to apply the same driving style with modern tyres has caused several chassis to break.

[LeonOfTheDead]

a similar story this, but perhaps more illustrative.
The Maserati 250F in its days used to be car that could be wonderfully powerslided, as it was a perfect combination of tyres and a flexible chassis. Trying to apply the same driving style with modern tyres has caused several chassis to break.

Excellent point. Possibly the 250F equipped with sticker tires could even result being slower on a twisty track.

[clutch-monkey]

a similar story this, but perhaps more illustrative.
The Maserati 250F in its days used to be car that could be wonderfully powerslided, as it was a perfect combination of tyres and a flexible chassis. Trying to apply the same driving style with modern tyres has caused several chassis to break.

ouch! the chassis isn't 'weak' as such, right? is it more the improvements in tires have far outstripped what the chassis was designed to deal with?

[henk4]

ouch! the chassis isn't 'weak' as such, right? is it more the improvements in tires have far outstripped what the chassis was designed to deal with?

yes, new tyres offer for more grip than the chassis can handle.

[RacingManiac]

I think in the case of race car, that point on chassis strength is more applicable than anywhere else. You always design from the tire up, you know the tire performance, which translate to cornering load and translate to design load for everything from chassis to suspension components. You design for a race car such that parts are at their limit at those load to minimize weight, and in most cases you use whats best available to you material wise to do so. In back in late 80s early 90s with the Group C cars were design for the tire at the time, their chassis would've been optimized for those condition, using period material(less strength, more weight...etc). Now slap on modern tyre thats more capable and they would've been beyond their designed envelope....I think even in historic racing now the tires they used are made to replicate the performance of period piece(perhaps with better production control). To make Wouter's point valid the car would need to be designed with modern technology and use modern tire....

[LeonOfTheDead]

Another silly example: in Formula 1 the tires are basically the main elastic component, with suspensions not helping much to soften bumps and kerbs.
Back in the days tires were much less performing, and also less rigid in their construction, regardless of the internal pressure. That would highly affect the drive.
Not only that, but with a more rigid component in place of a softer one, you could also have to deal with vibrations...see things breaking.

[TheScrutineer]

When Michelin and Bridgestone competed together in F1, you couldn't simply put Bridgestones onto a Michelin car. The suspension components were tuned completely differently as the tyres had two completely different 'philosophies'. Michelin relied on soft rubber being laid down on the racetrack and hot sticky soft tyres using this rubber to give awesome grip. Bridgestone however had a much harder tyre which relied on its 'dynamics', how it flexed under load etc to get its mechanical grip.

Also during this period as LeonOfTheDead said, most tyre testing for Bridgestone was done on a Ferrari, hence Ferrari kicked ass while most of the Bridgestone runners were at the back of the grid.