Top speed German inspection officials recorded an average top speed of the original version of 408.47 km/h (253.81 mph)[5] during test sessions on the Ehra-Lessien test track on 19 April 2005. This top speed was verified by James May on Top Gear in November 2006, again at Volkswagen Groups private Ehra-Lessien test track. May noted that at top speed the engine consumes 45,000 litres (9,900 imp gal) of air per minute (as much as a human breathes in four days). The Veyron at the time had the highest top speed of any street legal production car. Back in the Top Gear studio, co-presenter Jeremy Clarkson commented that most supercars felt like they were shaking apart at their top speed, and asked May if that was the case with the Veyron at 407 km/h (253 mph). May responded that no, the Veyron was very controlled, and only wobbled a tiny bit when the air brake deployed.[25] The cars everyday top speed is listed at 343 km/h (213 mph). When the car reaches 220 km/h (140 mph), hydraulics lower the car until it has a ground clearance of about 9 cm (3.5 in). At the same time, the wing and spoiler deploy. In this handling mode, the wing provides 3,425 newtons (770 lbf) of downforce, holding the car to the road.[21] For top speed mode the driver must, while stationary, toggle a special top speed key to the left of the drivers seat. A checklist then establishes whether the car and its driver are ready to attempt to reach 407 km/h (253 mph). If so, the rear spoiler retracts, the front air diffusers shut, and normal 12.5 cm (4.9 in) ground clearance drops to 6.5 cm (2.6 in). Braking The Veyrons brakes use cross drilled, radially vented carbon fibre reinforced silicon carbide (C/SiC) composite discs, manufactured by SGL Carbon, which have a much greater resistance to brake fade when compared with conventional cast iron discs. The lightweight aluminium alloy monobloc brake calipers are made by AP Racing; the fronts have eight[21] titanium pistons and the rear calipers have six pistons. Bugatti claims maximum deceleration of 1.3 g on road tyres. As an added safety feature, in the event of brake failure, an anti-lock braking system (ABS) has also been installed on the handbrake. Prototypes have been subjected to repeated 1.0 g braking from 312 km/h (194 mph) to 80 km/h (50 mph) without fade. With the cars acceleration from 80 km/h (50 mph) to 312 km/h (194 mph), that test can be performed every 22 seconds. At speeds above 200 km/h (120 mph), the rear wing also acts as an airbrake, snapping to a 55° angle in 0.4 seconds once brakes are applied, providing an additional 0.68 g (6.66 m/s2) of deceleration (equivalent to the stopping power of an ordinary hatchback).[21] Bugatti claims the Veyron will brake from 400 km/h (250 mph) to a standstill in less than 10 seconds, though distance covered in this time will be half a kilometre (third of a mile)
Posted on: Tue, 01 Apr 2014 10:55:58 +0000