Time Attack Project

[brysport]

I understand tyres aren't everything, but in saying that, no car will necessarily work better with a wider tyre. It needs to be designed around making that tyre work. Also on the horsepower front although SMP is a power track, how does an F3 car with 220hp and 550kg get around in 1:22? Okay so it doesn't have the frontal area, but they also don't have shedloads of downforce. Yes they have a good tyre, but not 10s worth of good tyre.

[andylaurence]

An F3 car has a tiny frontal area and weighs 550kg with driver - you've answered yourself. Your Cappucino will probably have twice the frontal area and weigh 100kg more with a lightweight driver. That means it'll need almost 20% more downforce and that means still more drag. All that extra drag means you need a lot more power...

[Tim.Wright]

The downforce to weight ratio is what gives you cornering performance. Downforce alone without a weight reference doesn't tell you much.

[Lycoming]

how does an F3 car with 220hp and 550kg get around in 1:22? Okay so it doesn't have the frontal area, but they also don't have shedloads of downforce.

The less it weighs, the less downforce it needs for equivalent cornering performance.

[TurboLag]

total weight, COG, inertia, drag.. oh, and COMPLETELY different tires than what is allowed in time attack.

A wider tire will always be better if you can get it into operating temperature and the aero drag and extra rolling resistance isn't the limiting factors.
The 295's used in WTAC have a HUGE diameter. For the Cappuchino, I'd maybe try the 275/35R15 Hoosier R6. I think they will be easier to fit..

[brysport]

I have contemplated using the 275 R17 (we have to run the Yoko in Australia) but once I have everything designed and can run through some simulations will I know. I am aware of the power/drag issues, if it was an easy task someone would have done it already (and in some ways some already have). I think it's a different approach and definitely do-able. I will make this work!