Anti-Spin: ARC not having a control tyre...

[Mark]

...for 2009 apparently because they couldn't come to a suitable balance between the Group N cars and the S2000 cars.
Read http://www.rally.com.au/home/columns/articleid=3120 for a laugh.


Now, seriously, is the difference between a Group N car and an S2000 that great that one car can't use a tyre that the other car does?
Well, the answer is probably yes.
I reckon an S2000 tyre probably has the following attributes:
-lightweight.
-thinner construction to match the lightweight.
-different spring rate due to the possible smaller side wall and hence the car's suspension is specificially tuned to that the sidewall spring rate.
-possibly smaller rolling diameter to maintain the 'torque at the wheels' rating that allows a car with half the torque to keep up the Group N car.
So, sticking a ~ 1400kg WRX or Evo on it, instead of the normal 1100 - 1150kg Corolla is going to be a problem in terms of the longevity of the tyre and blowouts under high sidewall loadings aren't going to look good for the sport nor tyre manufacturer.


Basically, why don't the ARC run the lowest common denominator? The standard every day rally tyre that everyone runs. The standard 205mm, 15" Brand X tyre. Should we be making exceptions for the 10% of the field, especially, when a control tyre should level the playing the field and reduce costs for the majority of competitors? It works for the WRC. Too much for the ARC. Oh, and while we're there, let's ban the grooving as well. That should make it more entertaining for the spectators.

It's an even easier choice than the in retrospect.
1) You run the S2000 tyre for everyone. I'm guessing as it is a very limited production run so it will cost more than anything else. Do anyone know the actual cost of one? Result:No privateers really test or can afford to change spring rates much or really care anyone or can noticeably pick up the difference, but maybe end up poorer as a result. Maybe a Group N overheats the tyre or maybe not.
2) You run the standard Pirelli/Dunlop/Silverstone/Yokie/Bridgestone/Maxsport. Group N cars same as before. Corolla's maybe slower. TRD test with Murray Coote for a day on the new tyre and get back upto speed. They then save the money on cheaper tyres during the year. Result: Everyone saves money. TRD put money into development of 'Polarizer' and go faster in 2009 than in 2008.
3) Don't do anything. I can't even be bothered into thinking about the numerous possiblilities, real or imagined, that govern this choice.


There's this quote from the article:

This sentiment was shared by Pirelli’s Australian Technical Director, Simon Pool. “With the World Rally Championship using a Pirelli control tyre and around a dozen other national rally championships around the world using Pirelli, we would like to extend into the Australian Rally Championship” said Pool.

“With some development we believe this would help make the ARC stronger; at this stage we just see it as a matter of developing an even balance between S2000 and Group N” said Pool.

Regarding the writing in bold, is Simon Pool saying that there is an 'unequal' force at the moment between the S2000 and Group N cars?


What Really Grinds My Gear: Just get on with making the sport an equal sport. Majority wins is the best you can do. There's no point in putting off the inevitable. There's three or four months for teams to get out there in testing.

'Swere.

Mark


P.S. Working on the basis that pop culture is cool and hence you'll agree with me in this anti-spin opinion piece I include a picture of a Storm Trooper and Bobba Fett

[Rainman]

Originally Posted by Mark

Now, seriously, is the difference between a Group N car and an S2000 that great that one car can't use a tyre that the other car does?
Well, the answer is probably yes.
I reckon an S2000 tyre probably has the following attributes:
-lightweight.
-thinner construction to match the lightweight.
-different spring rate due to the possible smaller side wall and hence the car's suspension is specificially tuned to that the sidewall spring rate.
-possibly smaller rolling diameter to maintain the 'torque at the wheels' rating that allows a car with half the torque to keep up the Group N car.
So, sticking a ~ 1400kg WRX or Evo on it, instead of the normal 1100 - 1150kg Corolla is going to be a problem in terms of the longevity of the tyre and blowouts under high sidewall loadings aren't going to look good for the sport nor tyre manufacturer.

[/IMG]

What you have highlighted is the core of the problem. I think that the control tyre would be only a single compound - most likely hards. So the problem isn't that they will blow out, rather that the lighter S2000 won't be able to get enough heat in to the tyres, leaving them at a distinct disadvantage.

I still think that it would be great for the sport - and would be a equaliser accross all budget ranges, as tyre consumption would be lower for all crews, and allow access to good second hand tyres for the budget crews.