Saturday 21 April 2007

Wheelspin... On a FWD Vehicle

As I've mentioned, my last car was an unruly little beast. An old Fiat Punto Sporting that was quite a hoot to drive and liked to be revved. So much so that on a favourite corner of mine you could stay well below the speed limit and still have the wheels smoking.

My new car doesn't do exactly the same. In fact it's very sensible. But, on the same corner going the opposite way you can wheel spin it. So out I was last night, making sure the wheels didn't get grip. Oh the joy! It did make me feel just a tad jealous of those with a rear wheel drive motor though.

For those of you who have never seen drift series racing or aren't familiar with the physics, lets go through how you do it (for rear wheel drift/spin):
  • A limited slip differential is really needed
  • Rear slip angle must be greater than front angle
  • This amounts to wheels pointing one way, car turning into the other
  • So basically, you put on the power, turn in to the turn then as the oversteer begins you can almost go into a correct but as the wheels haven't maintained traction you'll have drift
Of course, there are a huge number of ways in which to induce drift, some of which are covered over at Wikipedia. Remember, when the back end is going that's your oversteer - this can result in a spin out or a successful drive. The other end of this is understeer, when the nose keeps following a more straight-line trajectory than otherwise wanted. Or it can pull you in with the nose, making the slip angle of the front greater than the rear. Either way, you won't find many cars with a significant amount of understeer spinning out.

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