PJ1 TrackBite

PJ1 TrackBite, formerly known as VHT TrackBite or simply VHT, is a custom formulated synthetic resin, typically black in color, used in drag racing to either increase the traction of a car's tires or as a sealer for newly ground and/or resurfaced race tracks. It stays sticky for weeks, has fire-retardant properties and is hydrophobic. It is generally sprayed onto the track from either a 55-gallon (208-liter) drum or 1 gallon, 2.5 liter and 15 liter plastic jug. It has been used in professional racing since 1972.
It can also be sprayed from specialized VHT spraying tanks. The TrackBite that the NHRA uses, commercial "VHT TRACKBITE CONCENTRATE" is yellowish in color and per NHRA regulations is diluted with methanol for optimal effect. Trackbite contains no petroleum distillates and is biodegradable when dry.
Oval tracks also use TrackBite to provide extra traction in the corners of what would otherwise be a "one groove racetrack". 
Its use was prohibited by NASCAR in 2010 to reduce the amount of chemicals used at its events. However, it was used at Bristol Motor Speedway in 2016, 2017, and 2018, as well as Charlotte Motor Speedway and New Hampshire Motor Speedway in 2017 for races in NASCAR's top series (Cup, Xfinity, Trucks). Due to its frequent use in recent years at Bristol, TrackBite is often called "Bristol Bite." At Bristol it is used on the bottom of the track in an attempt to restore racing in the bottom groove that has been lost with changes to the banking in 2007 and 2012. Bristol and Charlotte both have regular Trackbite treatment trucks for their drag strips to prepare their tracks for their regular NHRA regional events along with their national events. Bristol's concrete surface uses the treatment similarly to the launch pad for the drag strip, which is concrete.
History.
The compound originated as a high temperature coating made for NASA by the Sperex Corporation. VHT, a brand owned by Sperex, began offering it for sale commercially. It was taken up by drag racers, and Sperex soon began producing formulations specially made for the sport. Sperex was purchased in 1989 by businessman P. J. Harvey and is now part of PJH Brands.