Pro Stock Drag Racing is a class of drag racing featuring 'Factory Hot-Rods'. The class can be known as "all motor", as the cars cannot use artificial induction such as turbocharging, supercharging or nitrous oxide, and there are very strict rules governing the modifications allowed to the engines and the types of bodies used.
Supercharging hardware is included in the 85 kWh, 70 kWh, and 60 kWh battery packs; in both the 85 kWh models and 70 kWh models, the payment for the car includes supercharging by default, but in the 60 kWh, supercharging was software-disabled and one must pay an extra fee to enable supercharging.
The National Hot Rod Association Pro Stock class emerged from the production-based Super Stock class in 1970 with a more liberal set of rules and an absence of handicaps. Rules initially favored big-block V8s but by 1972 (after the Sox & Martin Hemi cars captured the first two prostock titles handily) had changed to favor small-blocks to factor out the Chrysler Hemi cars.
In 1982, the NHRA implemented a new engine formula that allowed the big-blocks to return, due to the popularity of the Mountain Motor IHRA Pro Stocks with unlimited displacement in the late 1970s.
However, NHRA still limits the size of the engine to no more than 500 cubic inches(about 8,194 cubic centimetres) in displacement.
The GM small-block engine family is an engine design intended as the only V-8 engine used in General Motors' line of rear-wheel-drive cars and trucks. The GM small-block series was a "clean sheet" design with only the rod bearings in common in terms of shared parts with the classic Chevrolet small block V8.
The basic layout owes a good deal to the essential concept of Ed Cole's original small-block design of 1954-55, though the small-block engine also uses design cues from Buick, Oldsmobile, and Pontiac engines.
Some small-block engines are all-aluminum, especially the performance oriented engines, while others are cast iron. *note: to be perfectly clear, Gen I v-8 engines are Chevrolet while Gen II and up are GM small-block engines.
The rules that forbid forced induction of any sort, plus allowing head modifications, have resulted in Pro Stock heads being the most sophisticated in any drag racing category, with valve lifts in the 1" region.
There are a total of 52 km (32 mi) of ski runs with 14 ski lifts (six cable cars, seven chair lifts, three railways, and two drag lifts). There is also off-piste skiing, but guiding is often needed and should be used.
Pro Stock engines generally produce around 2.5 hp/in³ (114 kW/L).
A complete NHRA Pro Stock engine costs more than $250,000.
In addition to all of these specifications, each car must:
This makes for some incredibly tight racing; the front runners in the class can reach speeds over 213 miles per hour (343 km/h) in 6.47 seconds (approx). The qualifications rounds are separated by less than a tenth of a second across all competitors. In a particularly tight qualifying roster, the difference from #1 to the final #16 qualifier may be only .05 seconds.