Aerodynamics
The W8 had an estimated top speed of over 220 mph (354 km/h). However, in testing at the Bonneville Salt Flats, the W-2 reached 242 mph (389 km/h) with the less powerful Donovan block, as reported by Top Wheels magazine. This top speed was reached while still using the "high downforce" wing. Later aerodynamic testing further honed efficiency, bringing the car's drag coefficient (Cd.) down to just .32 prior to Department of Transportation crash testing in Ann Arbor, MI. The W8 design included subtle changes to the body during the production run, so that the initial car off the line looked slightly different from the last. These include the elimination of some gills, a lower front fascia and air splitter, revised rear wing, mirror intakes, and front grill. After the top speed testing was completed, no more Vector W8s were fitted with a removable glass roof, due to buffeting that occurred at those extreme speeds.
Read more about this topic: Vector W8