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If you go out and do a track school, they'll teach you about the friction circle. Under deceleration, a car's weight transfers forward. Under acceleration, the weight transfers rearward. Turning shifts the weight side to side. Getting the car through a corner at the limit is a matter of getting the right amount of weight on the right corner at the right time, and getting the appropriate weight transfer is a matter of smooth application of steering, brakes, and throttle.
There are very good FWD cars and very bad RWD cars, but at the cornering limit, FWD is almost always traction-limited in its ability to apply power. Most powerful FWD cars cannot be throttle-steered at the limit, because attempting to apply more power turns the inside wheel into blue tire smoke.
Most FWD racers are set up with a lot of rear roll stiffness, so that they will balance better in corners without large amounts of throttle, but that makes them highly susceptible to lift-throttle oversteer, where an abrupt lift off the gas in a corner - which can be unsettling in any car - will bring the rear end around old-Porsche quick.
In road use where one isn't cornering at the limit all the time, FWD's limitations are less severe. Still, wheelspin is still a perennial problem particularly on slippery pavement, particularly in spirited road driving - where you need to leave more margin under braking than on the track, but want to be able to accelerate hard through corners when the coast is clear.
A limited-slip differential can help mitigate these deficiencies, but few production FWD cars have one because cheap friction-type LSDs are troublesome in FWD applications, and the designs that do work well tend to be expensive. The best, the Quaife/Torsen/Peloquin-style helical-gear torque-biasing diffs, provide a level of throttle-steerability that can rival RWD, but they can also create a certain degree of 'wheel fight' in the steering if the front suspension scrub radius, wheel offset, etc. isn't just right. In my experience the tradeoff is well worth it; a 300-350HP FWD sedan with a Quaife is a lot of fun if sometimes a little ragged, a 300-350HP FWD sedan with an open differential is just frustrating.
Traction control doesn't count for much. It's a safety feature, not a performance feature. Without a limited-slip it can be annoyingly intrusive. The widespread use of stability control systems in RWD vehicles has taken most of the 'safety' argument out of the RWD-vs-FWD discussion, and while many RWD stability-control systems are every bit as annoyingly restrictive as most FWD stability-control systems, some manufacturers are dialing enough 'slop' into theirs (Porsche PSM, the 'track mode' settings in the Cadillac CTS-V and C6 'Vette) as to be enormous fun.
posted by 209.172.1...
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