Motorsport Terminology - R

R

R.T.

Acronym for "Reaction Time." In drag racing, it refers to the time it took for the driver to leave the starting line after the green light. This time usually means the difference between a win, or a loss, especially in the highly contested Pro Stock division where a difference of one ten-thousandth (.0001) of a second can put a driver in the winners circle.

Race Director

A Race Director may be designated for the entire duration of a Championship or Series. If so, it is understood that, during the practices and races for that Championship or Series, the Clerk of the Course and safety operations are under the ultimate authority of the Race Director.

Racing line

The fastest path around a circuit.

Rainout

When a race is delayed or cancelled due to rain, or the threat of rain.

Rail (or rail job)

dragster (as distinct from bodied car or flopper). From the exposed frame rails of early cars. Usually refers to early short-wheelbase cars.

Rail (drag racing)

guardrail

Ramp run

In a practice lap, to rev the engine as far as possible without changing gears to allow engine management systems to take Lambda readings of the fuel to air ratio across a smooth engine revolution range.

Rattle gun

See Impact Wrench.

Reactive suspension

A system by which the suspension is controlled by computer to maintain an optimum distance above the racing surface, regardless of forces acting upon the car and changes in the racing surface, thus maximising the aerodynamic assistance that can be gained by running the car close to the ground. Developed originally by Team Lotus in Formula One.

Redlight(ed)

(drag racing) a.k.a. bulb(ed)—jump(ed) the start, left before tree turned green. This is a loss unless a more serious (opponent crossing the center boundary line) foul occurs.

Relief driver

A driver who fills in for another driver in case of injury, or during a race because of exhaustion or pain.

Restart

The race is started again after a caution or other condition that stopped the race. In the case of a restart from a caution period on an oval track and most road courses, this is accomplished by the safety car pulling off the track, the green flag/light being displayed, and cars simply accelerating back to race speeds.

Retirement (often Ret)

see Did Not Finish.

Reverse grid racing

when the starting order of a race is reversed, so that the driver on pole position, starts last. Occasionally reverse grid is limited to only part of the grid, for example, just the top ten positions may be reversed. Often used to increase the entertainment value of a race, mainly used when a category races several times over the course of a meeting.

Riding mechanic

an early term for a co-driver.

Ripple strip

Concrete kerb, usually placed on the inside of a corner, painted in chunks of colour, usually red and white alternately, hence the 'ripple'.

Road course ringer

(NASCAR) A driver who generally competes only on road courses as a substitute for a team's primary driver. Such drivers are no longer used by top teams in the Sprint Cup Series due to competition changes in the 21st century, but are still frequently used by lower-tier Cup teams and teams in other NASCAR series.

Roll cage

Network of metal bars that criss-cross the interior of production-based sedan-bodied racing cars. Originally created as a safety device in more recent times is has been used to connect suspension, chassis, engine to substantially increase the torsional rigidity of a race car.

Roll hoop

Looped bar protruding above and behind the drivers helmets in open wheel and prototype sports racing cars. The hoop is placed that in the event of a car rolling over in a crash the car lands on the roll hoop rather than the drivers helmet. It also makes a handy hook for cranes for removing stopped cars from dangerous positions on the circuit.

Rolling start

A starting method where moving cars start a race after the starter displays a green flag.

Roof flap

an aerodynamic piece designed to keep a car on the ground when it is traveling in reverse.

Rumble strip

Variation of ripple strip with an upward-pointed, rounded saw-tooth edge. The saw-tooth effect is to discourage competitors from kerb-hopping. The saw-tooth creates a rumble sound and feel for the competitor when driven over.

Run-off area

Areas off the track put aside for vehicles to leave the track in case of emergency without accident.