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Old 01-29-2010, 01:24 AM   #16
BimmerDriver
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Great explanations John. And Dave, just to sum it up, if it makes it easier to understand just think of this. You know how when you send too much torque to the wheels they break loose and spin? Like when you build up revs and dump the clutch?

You can actually try this on a tight corner like a 360 highway ramp as somebody said with an AWD and a FWD. Just slowly increase the speed while cornering until you find the point where the wheels start to slide a little bit.

On an RWD when that happens the rear wheels lose grip, that is good from a handling standpoint because the tail slides outside and basically slingshots around like a pendulum pointing the nose towards the inside of the corner (where you want it to go).

On an FWD the front wheels would be the ones to lose grip, that's bad cause now the nose of the car would slide towards the outside of the corner where you don't wanna go, so you have that feeling you're going too fast for the corner and you won't make it, in order words, understeer. AWD are similar in that way cause they also have so much grip going to the fronts

Of course there are AWD cars that have exceptional handling even on tarmac like the R8 and the Nissan GTR but those send only about 20% traction to the front wheels and the rest to the rear to avoid this kind of situation. Most of these cars also have an automatic system that adjusts the traction balance sending more or less power to the fronts or rears depending on the situation. These systems solve the understeer problem but they are still way heavier than a simple RWD, that's why those are used in high end racing like F1

For tarmac racing then, RWD is the perfect combination because the front wheels do the steering and the rears do the propulsion instead of using the fronts for both. If you watch Top Gear at all, pay attention when you see Jeremy and his buddies testing those FWD hot hatches like those powerful VW Golf concepts and stuff, they have so much power on the front wheels that it just overwhelms the tires while cornering, you hear that understeer tire squeal, and the car struggling to make the corner hopelessly... When you see them testing RWDs though all you see is spectacular oversteers, that's cause they push it too much on purpose but overall that makes the car more maneuverable

As for Heel-and-toe and throttle blips for the turbo, Ayrton Senna was a master on that. Back when F1 used to have manual transmissions and turbos no-one knew how he was so fast until after they released the telemetry which showed that he used to blip the throttle really really fast during the corners and other drivers would just coast along the apex until it was time to get on the power again. Schumacher did something similar, but with automatics which was easier hahaha. Check Senna's foot work on this video, pretty sick stuff:
http://www.youtube.com/watch?v=yAwJsOECGBU

This other video about Schummi's technique is pretty interesting as well:
http://www.youtube.com/watch?v=Uk2p2nRK-p4

Last edited by BimmerDriver; 01-29-2010 at 01:51 AM.
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