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Old 01-20-2013, 12:40 AM   #14
fatoni
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Quote:
Originally Posted by Dimman View Post
To have a proper discussion about aero we need to clear up a few things.

First, we're dealing with lift. 'Downforce' is negative lift. So until all aero enhancements are working together to create negative lift, there is zero downforce. Downforce and lift are not independent forces. You have coefficient of lift. Once it goes negative you get 'downforce'.

Second, drag and lift have a complicated relationship. Sometimes one can be adjusted without the other being affected. Sometimes not. The drag to neg lift ratio is referred to aero efficiency. So while an F1 car has high drag, it also has ludicrous downforce. But that doesn't mean that we can't modify to get both a lift AND drag reduction.
Quote:
Originally Posted by CSG Mike View Post
What we've found in our testing is that additional mechanical grip generally is wasted, when you're already WOT (which is a LOT with this car).

For an extreme example, would you rather have 225 or 285 tires on a Miata? For a more realistic one, 225 vs 255? 195 vs 225? Of course it all depends on the situation...
the only reason i bothered mentioning the lift/downforce thing is because cars are shaped like aerofoils and have lift inherently. i think its important to talk about them separately because at any net amount of lift (positive or negative) you can have any drag coeffecient. adding downforce and removing things causing lift can be different.

there is some confusion going on here. we arent talking about the same things. i understand the importance of downforce and the grip that is provided. i was addressing the thought that running smaller tires would be a good idea in order to keep the drag coeffecient down. i was just saying that i would rather have mechanical grip over dropping a hundredth or so off the cod.

i also think aero grip is equally wasted if you are going wot. there are many people running around in miatas with 275s and in nearly every situation the miata with 225s is faster than the one with 195s. i do get your point though but wonder if it might be turning into a historical kinda myth. i think newer compounds are making the optimal tire width greater than they used to be but thats just speculation on my part.
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