when does anti lock brakes not prevent skidding
Anti-lock braking system In gravel, sand and deep snow, ABS tends to increase braking distances. On these surfaces, locked wheels dig in and stop the vehicle more quickly. ABS prevents this from occurring. Some ABS calibrations reduce this problem by slowing the cycling time, thus letting the wheels repeatedly briefly lock and unlock. Some vehicle manufacturers provide an "off-road" button to turn ABS function off. The primary benefit of ABS on such surfaces is to increase the ability of the driver to maintain control of the car rather than go into a skid, though loss of control remains more likely on soft surfaces such as gravel or on slippery surfaces such as snow or ice. On a very slippery surface such as sheet ice or gravel, it is possible to lock multiple wheels at once, and this can defeat ABS (which relies on comparing all four wheels, and detecting individual wheels skidding). Availability of ABS relieves most drivers from learning threshold braking.
GMC Syclone Both the Syclone and Typhoon trucks featured a Mitsubishi TD06-17C 8 cm² turbocharger[1] and Garrett water/air intercooler attached to a 4.3 L LB4 V6 engine with unique pistons, main caps, head gaskets, intake manifolds, fuel system, exhaust manifolds, and a 48mm twin bore throttle body from the 5.7 L GM Small-Block engine. All Syclones and Typhoons had a GM 700R4 4-speed automatic transmission. A Borg Warner all wheel drive transfer case split torque with 35% forward and 65% to the rear wheels.[1] Both trucks featured sport modifications to the standard suspensions. The Syclone was the first production truck to receive a 4-wheel anti-lock braking system. Output was 280 hp (209 kW) and 350 lb·ft (475 N·m).[1] The Syclone, when new, was capable of accelerating from 0-60 mph in 4.6 seconds and could do a quarter-mile run in 13.4 seconds at 98 mph (158 km/h) according to Car & Driver's comparison test.