Modifications for a drift ready car

There are some standard modifications made to cars that are tuned for drifting.

1. After market intake system; increases the amount of air going into the naturally aspirated motor.
2. Clutch and flywheel upgrade; due to the extreme use the clutch and flywheel are upgraded to stronger aftermarket pieces.
3. Limited slip differential; Install a limited slip differential. A 2 way lsd is the preferred choice.
4. Suspension; Make sure your suspension is correct. A stiff set of springs matched with the right damper, like a coil-over system, will allow the rear tires to spin a lot easier than a satock cars suspension. tower bars, roll bars, and roll cages can improve vehicle response and safety.
5. Wheels and tires; Wheels should be light wieght, the rear tires should be cheap, as you'll go through a lot of them, but make sure to have good quality front tires that will last.
6. Cooling upgrades; less air is moving across your engine since you are sideways a lot of the time. Aluminum race radiators and oil coolers are designed to reduce engine heat.

Now you now what you will need to modify to make your ride ready for drifting.

Top Drift Cars

Usually drift cars are light to moderate weight, rear-wheel-drive coupes and sedans. In Japan and worldwide, the most common drift machines are the Nissan Silvia/180SX, Toyota AE86, Mazda RX-7, Nissan A31 Cefiro, Nissan C33 Laurel, Nissan Skyline (RWD versions), Nissan Z-car, Toyota Altezza, Toyota Chaser, Toyota Mark II, Toyota MZ20 Soarer, Honda S2000, and Mazda Miata.

Techniques for inducing drift

Beginner techniques
These techniques don't use weight transition, so are typically the first thing the novice drifter learns. However they are still used by the most experienced drifters, and require skill to execute properly. These techniques aim to induce a loss of traction on the rear wheels, either by locking the wheel (e-brake drift), or using enough power from the engine to break the traction force (power-oversteer and clutch kick).
Hand-brake or Emergency brake drift - While the clutch is depressed, the hand-brake is pulled to induce rear traction loss. As soon as traction is lost, the driver releases the clutch, depresses the accelerator, and countersteers. This technique is used heavily in drift competitions to drift large corners, or to trim the car's line mid-drift.
Power oversteer or Powerslide - This drift is performed when entering a corner at full throttle to produce heavy oversteer through the turn. The excess power causes the drive wheels to lose traction in a RWD or AWD car. This is the most typical drifting technique for all-wheel drive cars.
Shift lock (compression slide) - Initiated by downshifting (usually from third to second or fourth to third, and using a very fast shift) instead of braking, without rev-matching, causing the drive wheels to lock momentarily. Helpful for very tight corners, allowing the driver to approach the corner at a slower speed and lower revs, while allowing quick acceleration when exiting the corner. This technique can be very damaging to the engine if mis-used as the ECU is unable to rev limit when the engine is oversped by the rear wheels. Premature downshifters are called "Rod Stretchers".
Clutch kick - This is done by "kicking" the clutch (pushing in, then out, usually more than one time in a drift for adjustment in a very fast manner) to send a shock through the powertrain, upsetting the car's balance. This causes the rear wheels to slip. The foot should be at an angle so the brake and gas may be pressed as well, this being needed to control speed and stop from spinning out in the drift.

Weight transition techniques
These techniques employ a further concept of weight transition. When a vehicle has the load towards the front, the "lighter" back is easier to steer, causing an oversteer condition that can initiate a drift.
Braking Drift - This drift is performed by braking into a corner, so that the car can transfer weight to the front. This is immediately followed by throttle in a RWD car causes the rear wheels to lose traction. FWD cars can also use this technique as it does not depend on the rear wheels being driven.
Inertia (Feint) drift, or Scandinavian flick - This is done by transferring the weight of car towards the outside of a turn by first turning away from the turn and then quickly turning back using the inertia of the rear of the car to swing into the desired drifting line. Sometimes the hand-brake will be applied while transferring the weight of the car towards the outside to lock the rear wheels and help the rear swing outwards. This type of drifting causes the car to accelerate faster afterwards, because of momentum built up while drifting.
Kansei, Lift off, or Taking In - By letting off the accelerator while cornering at very high speeds, cars with relatively neutral handling will begin to slide, simply from the weight transfer resulting from engine braking. The drift is controlled afterwards by steering inputs from the driver and light pedal work, similar to the Braking drift.

Other techniques
Dirt drop - This is done by dropping the rear tires off the sealed road onto dirt, or whatever low-grip surface borders the road, to maintain or gain drift angle. Also colloquially called "Dirt Turbo".
Choku-Dori - This is done by swaying the car's weight back and forth on straightaways, using countersteer and throttle to maintain a large angle. This is a show maneuver that usually involves many cars following the same line.
Ski Drift - This extremely difficult and dangerous drift is done by drifting while the car is on two wheels. If not done perfectly, the car will likely roll over and crash.

Suspension Tweeks

The suspension in a drift car tends to have very high spring and damper rates. Sway bars are upgraded, particularly on the rear. Caster is often increased to improve the car's controllability during a slide. Most cars use an integrated coilover/shock (MacPherson strut) combination. This type of suspension allows the ride height to be adjusted independently of the suspension travel. There is no perfect height setting or spring/shock combo for any car, but each driver will have their own personal preference. Many suspension manufacturers offer suspension tuned specifically for drifting, allowing many people to enter the sport competitively.