I have mentioned the Road & Track 1/4 mile test of the 458: 11.0 @ 128.5. From R & T:
Acceleration
" The single most telling quantitative metric we use that displays effective power a car makes (or how well it uses that power) is acceleration testing. We report standing-start times to speeds of up to 130 mph and time-to-distance figures of 100 ft., 500 ft., 900 ft., and 1320 ft. (a quarter mile).
Although we record the ambient conditions at the time of testing, we do not adjust our figures to compensate for temperature, humidity, elevation and the like. We do, however, still follow the NHRA drag-strip procedure of a 1-ft. rollout, where the time it takes a car to travel 1 ft. is subtracted from the raw times (this ranges from 0.2 second to as much as 0.4 sec. depending on the amount of wheelspin a vehicle sees at launch). Why this 1-ft. distance? At NHRA drag strips, timing doesn't begin until the vehicle has traveled roughly one foot.
Many high-performance cars nowadays come with various built-in assist systems (like launch control) which help a driver achieve repeatable maximum acceleration from a standstill, and no-lift shifting, which allows you to maintain wide-open throttle while shifting a traditional manual gearbox. While we readily employ every helpful electronic aid a car offers, we test just about every configuration possible to achieve the quickest result. This often means turning off traction/stability control to prevent the computer from bogging the engine, and sometimes even ignoring certain "launch control" systems altogether if our right foot can do better.
The optimum amount of wheelspin we get at launch depends heavily on a car's engine characteristics as well as the number of driven wheels. Some cars that make gobs of torque down low benefit from little to no wheelspin (a Dodge Viper, for instance), while others that like to be revved to the stratosphere require copious amounts to stay within their powerband (think Honda S2000). This is typically a trial-and-error process that gets shorter once you begin to figure out what types of cars respond best to certain methods.
The test notes in every road test data panel typically outline the procedure we used to get the best performance, and includes launch rpm, the amount of clutch finesse, and optimal shift point if it occurs before redline. "
http://www.roadandtrack.com/special-report/how-we-test
3Likes
Threaded Mode
