The condition that exists when a turbocharger is producing power. When exhaust pressure is sufficient, the turbine spins, and the turbo is on boost. Read More »
Pretensioner
Device that retracts the seat belt to tighten or take up slack in the wearer’s belt. When a collision occurs, a seat belt with a pretensioner detects the incident, or that the brakes have been applied, and tightens the belt before the wearer is propelled forward. This holds the occupant more securely in the seat. Read More »
Red Flag
A solid red flag is used to stop the race immediately. Generally races are stopped for bad accidents or weather. Occasionally, a multiple car pileup will halt a race. Wreckers and fire marshals clear the track of cars, debris and fluids. Alternatively, rain makes the surface of the race track dangerous. Once NASCAR officials authorize the race to start again, ... Read More »
RPM
Revolutions Per Minute — a unit of measure used to express the rotational speed of an engine. Read More »
Straight-Line Speed
The highest speed obtainable by a vehicle driving in a straight line. Read More »
Struts
A metal bar or rod that provides the suspension system with structural strength. Read More »
Traction Control
An option on many cars today, especially sports models. When engaged, this device “senses” when a driving tire has no traction, and attempts to compensate by slowing the wheel movement. This is good for getting traction in an area where it may normally be hard to do so (i.e. snow, gravel, rain). Traction Control was developed in Formula One racing ... Read More »
Upright Seating Position
Sitting straight up on a motorcycle with raised handlebars, where your hands are level with the bend in your elbows. It is the easiest and most comfortable position in which to ride a bike because no part of your body is faced with undue stress based on position. On motorcycles where the rider is leaning forward or backward, backs and ... Read More »
X-Valve
There are two kinds of valves in a car, intake and exhaust. The intake valves allow oxygen and fuel into the cylinder head and the exhaust valves allow the used-up gases to exit. Read More »
Active Safety Features
Those that interact with, or are controlled by, the driver. For example brakes, Anti-lock braking system and traction control Read More »
