"how to gain front grip in the wet thanks Gary "
This is general advice on setting up for the wet.
Everything that you have heard about setting up in the dry applies to the wet but since the forces on a wet kart are much lower, you have to make adjustments to suit.
So, it your kart is stiff in the dry, then you have to loosen up everything for the wet. Think about it.
When you corner in the dry the weight goes onto the outside front wheel. This bends or flexes the chassis both transversely (from side to side) and longitudinally (from front to rear) You set the camber so that when the kart is fully flexed, the wheel is flat on the road giving maximum grip.
You cannot get the same amount of force in the wet so you make the front end more flexible and adjust the camber to suit the new amount of flex that you can get.
At the same time, the back wheels need to lift. Just as setting up for the front you need to compensate for the loss of force bending the kart, so you increase the jacking effect of the caster and also increase the width of the front track. (the width of the track increases the jacking effect, look at it as a lever).
You reduce the stiffness between the rails (torsion bar out) at the back to allow the wheels to move a greater amount independently or rather to move further for less force. Indeed, you can add in the fourth rail if you have one to increase the amount of differential movement at the back.
Lastly, the kart transfers weight from rear to front when you brake. As you know, if youy turn the steering on the grid, it only lifts the outside front wheel. It is the transfer of force from front to rear that forces the front down and causes the back to lift. Again, in the wet the braking force is much lower, so you may need to bring the driver forward to create more force on the front. Start off by sticking an inch of bubblewrap in the seat back to bring you forward.
The other thing is that even though you have may the back end lift more, the conditions mean that you have lost more in force than you have gained in flexibility. You may need to move the rears out so that they are clear of the ground that bit earlier.
Now when you go out you may find the kart has become very sensitive to the front end. It twitches in, spins very easily and the back breaks away quickly. It is time to balance the forces so that you can drift your kart evenly without losing control, so gradually decrease back end lift (increase back end grip) until you find a balance. (Obviously there is a point where you can give up front end control as well to make the balance).
Tyres:
Tyres are designed to operate at a certain pressure in order to put the bigesst and most constant contact patch on the ground in a corner.
Normally that seems to be around 1 bar (14.5 psi). Putting more pressure in than that bends the tyre out of shape and 'domes' the tyre. If you think of the tyre as a rigid, rightangled box, then if your camber adjustment is wrong the tyre will only run on a corner of the tyre, and overpressuring the tyre will make you run on a slightly bigger area because of the 'dome'. Getting the camber right will triple the grip that overpressuring the tyre gives you. (Though overpressuring is a quick way of checking that you have the camber wrong)
Lastly to driving technique. A kart is vastly more unstable under deceleration than it is under acceleration, and cornering is a deceleration. In the low grip conditions of the wet, going into a corner without your foot on the throttle means that you are twice as likely to spin as with your foot on the throttle. Of course, in the wet this means gently on the throttle, not the full boot one can use in the dry.
Secondly, you have to be more aware of the braking point. You brake on the straight (the most stable direction) but need to turn the wheel while the force is still acting on the front wheels (one of the reasons for moving the seat so you always have weight on the front). Then you use the offset effect of the outside rear wheel to power you round the corner.
you have to monitor very carefully what is happening and often have both brake and throttle going at the same time. You don't want wheelspin or slip on any wheel unless you are deliberately drifting the kart.
One of the mistakes the less confident make is to go into a corner too fast, brake too hard and then sit in a slide until the speed has dropped enough to allow the front to grip. Often just a trickle of power at that point will give them grip that much earlier.
Lastly, know the track. Even little ridges can give you the edge needed, and you have to be happy drifting along, confident that when you hit that ridge, you will get control back.
So at Clay, just after the kink, there is a tiny piece of worn track about a foot wide and 8 foot long. Hit that in a drift and accelerate at that point kicks you straight towards the braking point for Billys. Immediately you are straight it's hard on the brakes.
Do it right and you can take the kink nearly flat out, easing off in the drift so you have throttle for the kick. Doing it blind with a kart in front of you, proves the power of prayer.
Miss the patch, or try to brake, not accelerate and the track turns rapidly green.
It's not just front end grip that counts, it's knowing what you can do with what you have.
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HELP!! wet setup please by 'garycooper01' (10 Nov 2008 @ 18:43)
