The corkscrew left/right, often referred to as cork l/r, is a typical stunt track element. The standard driving line around a cork l/r requires spiralling along the track direction axis in order to avoid crashing at a wall separating the left and right halves of the track. Rounding it properly requires significantly more from the driver than a regular loop, and thus the cork l/r is often a daunting challenge for newbies. Corks l/r can be driven through in a variety of ways, the differences in effectiveness between them often being quite subtle. For that reason, they can go a long way in adding spice to a track section.
Ways around a cork l/r
The standard line around a cork l/r consists in following the yellow line, starting from the right side of the track then going upside down as one drives above the wall and finally re-emerging at the left side of the road. Such a line is enforced by IRC rules and most other OWOOT rule sets. However, even under free rules driving the cork l/r the regular way is occasionally useful. At moderate speeds (at which the line can be completed without braking), the time saved by one of the various cuts is not as large to rule out the standard line entirely (as it happens with loops and loopcuts). That is specially true when the cork l/r is immediately preceded or followed by corner combinations, which may cause the standard line to actually become faster than a cut. For Indy and Acura, power gear must be accounted for as well.
Right-side cork cut
One of the elementary shortcuts in Stunts, the basic form of cork l/r cutting is often discovered early on by newbies, out of frustration with the standard line. It consists in simply driving straight through the cork, climbing on the right side of the cork surface while swerving a little to the right in order to avoid hitting the wall. That cut often allows for saving a few tenths while actually being easier to pull off than the standard line. Useful small jumps can also be attained both at the entrance and exit of the cork.
Left-side cork cut
The idea of this cut is the same of the much more common right-side variant, except for being done at the left-side. That makes it quite a bit harder, since the car must be driven through a much narrower gap at the cork entrance. Completely avoiding driving on grass tends to be more difficult as well. Still, the left-side cut is occasionally advantageous depending on the track combos the cork is placed at.
Driving over the cork
Now this is a much more advanced line, which usually requires some RH to be effective. Attempting to coast along the outside of right edge of a cork l/r or, occasionally, landing a jump at the top of the cork may make it possible to drive over it on its outer surface. Keeping the car stable at such a precarious position can be difficult, and collision bugs involving the cork surface are almost sure to happen (such bugs can be a nuisance, but they can be exploited for surviving the trick as well). The possible gains with this trick usually involve being able to pull off longer/higher jumps at the exit of the cork, or managing to drive through it at speed after a slide.
Corks l/r are sometimes used to pull off long jumps, through not nearly as often as loops or banked road segments. Common ways to do so include climbing the outer surface and exploiting the resulting instability of the car and driving straight into the cork at speed and at a right angle to the track direction, which (thanks to surface and collision bugs) allows one to use it as a launch platform. Long cork jumps starting from the drivable inner surface are extremely rare, even in top class competition racing. A remarkable example is the trick combo which gave Ayrton victory with ZCT86, which started with such a jump.