We often get many questions on what a lot of our terminology means, so we've decided give you a peak into the "racer's circle" with this handy glossary. If you have something for us to add, or just have feedback, please drop us a line.

AMPS- Amperage:
The ampere, in practice often shortened to amp, (symbol: A) is a unit of electric current, or amount of electric charge per second. The ampere is named after André-Marie Ampère, a 17th century French dude who was one of the main discoverers of electromagnetism.

Armature:
The central part of an electric motor, usually carrying the windings and the commutators. The pinion gear) is usually attached to the armature shaft.

ATVor EPA:
Adjustable Travel Volume or End Point Adjustment features on better radio transmitters control the maximum travel of the servo on both sides of neutral position.

AWD:
All four wheels are powered by the motor through a drive train. The use of four wheel drive allows a car to obtain better traction and greatly improves handling.

BEC:
Battery Eliminator Circuitry; a circuit that eliminates the need for a separate receiver battery by using the battery pack that powers the vehicle also powers the servos.

BDC:
Abbreviation for Bottom Dead Center. When a piston is at the very bottom of it's stroke.

Brushless Motor:
A motor that has a rotating center permanent magnet & a fixed outer electromagnet driven by a special ESC that changes AC pulses to DC pulses.

CA Glue:
CA stands for "Cyanoacrylate" (commonly referred to as "super glue" outside the hobby). This glue is fast drying and works well on wood, most plastics and other building materials. It can destroy foam surfaces.

Camber:
Camber is the angle of the wheel relative to vertical, as viewed from the front or the rear of the car. If the wheel leans in towards the chassis, it has negative camber; if it leans away from the car, it has positive camber.

Camber:
The angle of the tire in relationship to a vertical 90 deg plane. If the tires are closer to each other on the top (leaning in towards the chassis at top), this is called negative camber. If it is opposite, then it is called positive camber.

Carbon Fiber:
An extremely strong thin fiber made by pyrolyzing synthetic fibers, such as rayon, until charred. Very light and strong.

Carburetor:
The carburetor on a glow or gas engine mixes fuel and air into just the right proportions as to cause an efficient "burn" or explosion in the combustion chamber of the engine. To "lean" a mixture means there is insufficient fuel. To "rich" a mixture means there is too much fuel for the motor to efficiently burn.

Caster:
Caster is the angle to which the steering pivot axis is tilted forward or rearward from vertical, as viewed from the side. If the pivot axis is tilted backward (that is, the top pivot is positioned farther rearward than the bottom pivot), then the caster is positive; if it's tilted forward, then the caster is negative.

Center of Gravity:
This is the point at which the model balances for the best balance of maneuverability and stability.

Chicane:
A chicane is a sequence of tight serpentine curves, usually an S-shape curve.

Choking:
The Engine Choking the engine refers to placing an object over the carburetor in order to create suction that will draw fuel from the tank into the combustion cylinder of the engine. This is also known as "priming" the engine. On some older setups, one can squirt fuel directly into the carburetor to accomplish the same result.

Dampening:
The action of slowing down the suspension through use of friction or viscous fluids.

Dampening Disks:
Disks pressed by spring tension against a pressure plate used to create friction-based damping.

Dampening Fluids:
Viscous fluids, usually silicon based, used to slow down suspension action.

Differential:
A drivetrain element that transfers the power down to the wheels assisting in the distribution of such. There are two types at this scale, Gear Differentials and Ball differentials. Gear differentials feature planetary-type conical gears, mated to to ring gears on each output side, these differentials are adjusted by using different grade viscous fluids or greases to aid in power delivery. Ball differentials use a pressure plate to ball bearing system in which the plates "sandwich" small ball bearings to engage drive power to both output sides. Differentials essentially assist in power delivery to the ground by distributing the power between the two wheels they are driving, this is necessary since the outside wheels on a corner are traveling a longer distance than the inside ones, therefore needing to accelerate to a higher speed. Differentials allow for this to happen.

Damping:
Damping describes the lessening of impact on a car through its shock absorbers. Damping can be accomplished by changing the stiffness of a shock absorber. A "soft" damping shock can provide more traction in a turn but limits responsiveness because the car must "recover" after the turn. On the other hand, "stiff" damping increases responsiveness, but compromises traction in severe turns.

Differential:
A differential is a gearing mechanism that permits the drive wheels (powered wheels) to spin at different rates while turning. Since wheels on the outside diameter of the turn must travel a greater distance than those on the inside, the differential eliminates slippage on the turn.

Direct Drive:
The pinion and motor drive the wheels directly on the vehicle.

Diving In:
This is a racing term and is the ever important skill of cutting inside of someone who makes a wide turn.

Dogbone:
A part of the drivetrain connecting the out-drive to the axle. This allows the differential to transfer power from the engine out to the axle and tires of the car or truck.

Drafting:
Drafting is the action of following a vehicle closely enough to shield your vehicle from the wind that would normally cause drag on your vehicle.

Drag:
The force that resists movement of any object through the air. Can apply to surface or air vehicles.

Droop:
Droop is the distance the wheel drops from normal ride height when the car is lifted off the ground. Adjustment is either via droop screws in the wishbones that rest on the chassis; or spacers under the shock piston inside the shocks. Droop is another tuning aid and can have a dramatic effect on handling.

Dual Rates:
Dual rates are simply transmitter switch inputs that allow the user to program two sets of control parameters that the user can switch to instantly.

ESC; Electronic Speed Control:
This device controls the throttle function on electric vehicles and aircraft. Some ESC's come with an automatic shut-off feature that simply shuts the motor down if the voltage in the battery becomes too low. This is done to conserve power for servos that operate the control surfaces.

Fail Safe:
A separate device that communicates pre-set "safe" transmitter positions to the receiver in case communication between receiver and transmitter is interrupted for a specified period of time (usually a short period).

FET:
Field Effect Transistor; these are used in the speed controls to control the amount of power delivered from your batteries to your motor .

Fish Tail:
Your car's rear end slides out, causing it to possibly spin around completely. Also known as being "loose".

Flooding:
Happens on nitro cars. This is where there is too much fuel in the combustion chamber of an engine, causing it to choke and not fire, due to increasing pressure.

Frequency Board:
A system used for multiple Drivers to determine what Frequencies are in use within his or her driving area. Each Drivers Radio frequency will be announced or posted in a designated area to let other Drivers know what frequencies are in use to prevent Radio interference between Radio systems.

FRP:
Abbreviation for fiber reinforced plastic which is molded with synthetic fibers to add rigidity and strength into existing shapes and parts

FWD:
Abbreviation for "front wheel drive" where only the two front wheels are powered by the engine/motor through the drivetrain.

Gear Ratio:
The relationship between spur and pinion on a car. This is Calculated by dividing the amount of teeth on a spur by the number of teeth on the pinion.

Glitch:
Sometimes called a "hit", a glitch is a temporary interruption in the radio signal being transmitted from your transmitter to your receiver. With the advent of PCM transmission standards and synthesized modes of transmission, glitches are becoming more rare.

Glow Igniter:
A device that attaches to a "Glow Plug" in order to heat the plug to a sufficient temperature to cause combustion to begin in the cylinder of a glow engine. A glow ignitor is powered by a 1.5 volt battery in most instances.

Glow Plug:
Similar to a spark plug in a car's internal combustion engine, the glow plug is a filament that literally glows in order to ignite the fuel inside the engine cylinder. When a glow engine is first started, a "Glow Ignitor" is attached to give the filament a very high temperature. Once the engine is running, the combustion keeps the temperature of the filament high enough to sustain the engine.

Inserts:
Rather than inflating tires with air, some 1:18 scale and up R/C tires use foam inserts that give cushion to the tire.

HSN:
High speed needle. This needle found on nitro engines controls the maximum amount of fuel that can enter the engine at ANY throttle opening. It also serves to adjust the fuel/air mixture from part throttle to full throttle. In vehicles, proper adjustment of this needle will allow an engine to attain maximum rpm and horsepower without causing a lean condition. Adjustment of this needle should be done BEFORE adjusting the low speed needle.

Hub Carrier:
The parts of the suspension system that hold the axles and bearings on which the whiles of the vehicle rotate. Also called "uprights".

KPH:
Kilometers Per Hour is a metric unit of speed

Lean Mixture:
This refers to the air/fuel mixture on an internal combustion engine. A "lean" mixture means that there is not enough fuel compared to the amount of air entering the combustion chamber.

LHS:
A common abbreviation for local hobby shop.

Low End Valve:
A valve for tuning a 2 stroke engine in the lower band of its RPM range. Properly adjusting the low end helps ensure a smooth transition from low to high speed.

Loser:
That would be Rob, as he will likely finish dead last in any race he enters.

LSN-Low speed needle:
This needle found on nitro engines controls the idle and just off idle air/fuel mixture. In vehicles, proper adjustment of this needle will allow a consistent idle as well as immediate and explosive acceleration. Adjustment of this needle should be done after the high speed needle is properly set.

Needle Valve:
Found on Nitro engines. A needle valve is a threaded screw with a finger grip that permits the user to regulate the flow of fuel into the carburetor of a motor. Many larger glow motors have two needle valves to control flow rates at different motor speeds (e.g. medium and high range valves).

mAh
Stands for Milliamp Hour. This is a measure of a battery's total capacity. The larger the number of milliamps, the more power the battery can store. Batteries for today's electric Cars typically run 3,300 mAh packs. Do not confuse milliamps with volts!

Marshal, Corner Marshal or Turn Marshal:
A person who fixes cars due to a crash or pile-up during the race.

MPH
Are you daft? It's a unit of speed; Miles Per Hour...

Newbie:
A beginner in the hobby. Can be used as a humble self-description (I'm just a newbie...), affectionately (I just helped a newbie make his first lap!) or sarcastically (What are you, a newbie???).

Nitro Fuel:
Nitro fuel is used in nitro engine applications and can contain 5-50% nitro methane

PCM:
PCM stands for Pulse Code Modulation. PCM in R/C is actually no closer to an accurate description than PPM! PCM is another encoding scheme, not a modulation scheme.

Peak Battery Charger:
A peak charger automatically ceases charging when your battery is fully charged.

Pinion Gear:
A gear that fits over the drive shaft of a motor. By adjusting the number of "teeth" in the pinion gear, you can increase the torque or overall drive speed of the output device (be it a propeller or wheels). An increase in torque will result in a decrease in speed and visa versa.

Polycarbonate:
A type of glass reinforced plastic used in R/C car bodies and various applications due to its high performance use and tough design- Flexible.

Potentiometer:
The potentiometer (or 'pot' for short) describes an electronic component which has a user-adjustable resistance. Usually, this is a three-terminal resistor with a rotating contact in the center. In R/C it is often used to determine the steering servo position.

PPM:
PPM stands for Pulse Position Modulation and is a term describing the concept for encoding using the scheme that came into being in the early 1960�s.

Pre Load:
Is the distance a spring is compressed from its free length at full extension. This is usually done with different sized pre load clips inserted between the spring and shock.

Pressure Plate:
Static plate usually made of Carbon Fiber, Fiber Glass or Titanium, which is used to create friction dampening by forcing spring-loaded Dampening Disks against its surface.

Proportional:
Usually refers to an R/C car that has proportional steering or throttle. This means the wheels turn in proportion to the amount that you have turned the steering wheel on the transmitter and same for the throttle. A non proportional system would turn the wheels either all the way right or all the way left and the throttle would be all on or all off.

Racing Heats:
Heats are specific to category. You have several different categories at an event (F1, AWD Stock, Touring Modified, 2WD Stock, amongst others), heats are break downs of the specific categories. Most big events have more than 6-8 cars in a specific racing category, so it is necessary to break them down into different heats in order for everyone to get a chance to run in that specific category.

Racing Rounds:
Rounds are specific to heats. Every heat race gets to run 3 or 4 times. The first time the specific heat qualifies is round one, the second is round two, and so on.

Racing Qualifier:
At any organized racing event, qualifying is the initial part of the race in which drivers battle against the clock, to find where they rank versus the other drivers in the same category. Qualifying usually consists of 3 or 4 rounds, in which drivers compete in 5-8 minute runs to see who can run the most laps in the time allotted. Whoever runs the most laps in the time specified becomes the TQ (Top Qualifier) and gets to start first on the grid on the A Main.

Racing Staggered Starts:
At many events this is the choice for qualifying format. What happens here is every driver in the specific heat, gets to start on his own clock while running together with other cars on the track. This enables the drivers to actually race the clock instead of each other while they are together on the track. This is also known as an IFMAR start.

Racing Mains:
The Mains could also be called The Finals. This is where racers go heads up in a battle for the title of the event. Depending on the size of the track there can be anywhere from 6 to 8 cars in a specific final. The larger the track the more drivers making it into the "main". The 6 or 8 Top drivers in Qualifying For the specific category in which they are competing get to go head to head in the A-Main, which decides the title. Remaining qualifiers ranked below that fill up the lower mains according to where they finished in qualifying (B-Main, C-Main, etc, and lower, until all drivers fill up a spot on a final). In certain events, "Triple A-Mains" can be run. Triple A-Mains is defined as the A Main being run 3 times. Kind of like a small race- off. At the end of the Three mains, the competing Driver's finishes are averaged out to determine the winner. The highest average finish (highest being closer to first place) takes the title. Two wins automatically clinches the title for the person who does it. The reason for triple A-Mains is to eliminate the element of luck in a specific race, this way the top racer (s) gets to come out on top even if he is struck by bad luck in one of the specific A-Mains.

Receiver:
An electronic device designed to receive radio transmissions from the transmitter and translate the commands into servo movements or electronic signals for electronic speed controls, gyros and other electronic equipment connected to the receiver.

Roll Center:
is the virtual pivot point in space that a car rotates around when subjected to cornering forces.

RPM "Revolutions Per Minute":
The number of times a wheel, motor shaft or other rotating part will turn in one minute.

RTR "Ready to Run":
These vehicles come ready to go out of the box. Most only require the installation of batteries.

RWD (rear wheel drive): Only the two rear wheels are powered by the engine/motor through the drivetrain

Servo:
A small electrically powered motor encased in plastic or metal (typically plastic) with an arm protruding from the side or top. The servo takes control input from the receiver and is used to translate transmitter control changes into movement of control rods, levers or other mechanical linkages on the radio controlled vehicle.

Servo Reverse Switch:
Most transmitters have switches that permit the user to reverse the direction of the servo controlled by the applicable channel reversing switch.

Shock Absorber:
A device that softens the shock that occurs when a car wheel runs over an obstacle, turns sharply or drops sharply into a rut in the road. Shock absorbers can be made using a coiled spring assembly or by using a piston and oil setup that uses the viscosity of the shock oil to regulate the stiffness of the shock absorber. This is also called a damper.

Slipper Clutch:
Typically found on monster trucks and other off-road vehicles, the slipper clutch regulates how much engine power is transmitted from the drive gears to the wheels. The device is used to maximize a vehicle's traction.

Spread Spectrum:
A new generation of radio systems operate in the 2.4GHz range and send digital signals back and forth between the radio and the car. These are virtually immune to interference and allow you to place sensors in the car and monitor things like RPM, Speed, Temperature and voltage.

Spring Rate:
The stiffness of a spring measured by a unit of length over weight or by overall rigidity. This determines how much a spring compresses under load.

Stack:
The armature in an electric motor is made up of a stack of plates that are joined together to form the wiring into the appropriate shapes. Stack length can be varied to change performance properties.

Slippage (Differential Slippage):
Amount of slipping the pressure plates have in relationship to the ball bearings inside a differential before it engages.

Springs:
Coiled metallic wire used to adjust tension on different parts of a suspension.

Spring Rate:
Amount of force necessary to compress a spring. Usually measured in lbs/in or g/mm.

Spur Gear:
Gear, which Pinion spins that delivers the power coming from the motor to the drivetrain.

Toe In /Toe Out:
Angle in which the tires are either pointing in (toe-in) or pointing out (toe-out) in relationship to a straight line parallel to the car.

In simple terms in the front Toe in gives you less entry steering and more exit, also makes the car more stable in a straigh line. Reverse the effects and that is what toe out does.

In the rear more to in gives you more entry steering, and the car has a lot more traction through the middle and exit part of a turn. Usually takes away a little corner speed in exchange for driveability. You NEVER use toe out in the rear.

Timing System:
Timing systems are employed at most clubs and sanctioned events. These systems consist of a transponder on the car and a coil or bridge that the car will pass over or under. The information is passed to a PC which tracks the cars with software written for the purpose. There are a few common types of timing systems on the market as detailed below:



Tire Shore:
Hardness of the the tire, usually measured in degrees. Higher degree is a harder tire, lower degree is a softer tire.

Tire Tread:
Pattern molded into Rubber tire, that aids in increased traction on surfaces.

Toe Angle
The toe angle of a car is the angle of the tires from 0 degrees when viewing the car or truck from above. A "toe in" refers to wheels that are angled slightly in when the steering mechanism is neutral. Slight toe angles provide stability, but too much creates friction and is inefficient. Toe-out on front wheels provides more responsive steering but less stability. Toe-in on rear wheels provide stability and most cars are manufactured that way.

Touring Car
Touring cars are standard street cars that are modified for racing (e.g. Skyline). There are hundreds of R/C touring cars available on the market. Most R/C versions are all-wheel drive.

Track Width
The distance between the midline of each tire measured on either the front or the rear set of wheels.

Understeer
The opposite of oversteer (duh), this condition results when the car or truck's front tires have less grip than the rear, causing it to "push" through turns.

Volts
The three most basic units in electricity are voltage (V), current (I) and resistance (r). Voltage is measured in volts, current is measured in amps and resistance is measured in ohms. If we compare an electrical system to a water system, it would shake out like this:
The voltage is equivalent to the water pressure, the resistance is equivalent to the pipe size and the current is equivalent to the rate at which the water is flowing. The relationship between these three can be stated as follows: I = V/r (Current in Amps is equal to voltage divided by resistance)

Wheel Offset
Wheel offset is the additional distance from the center of the wheel to the inside part of the wheel that attaches to the axel. If a vehicle has a 2mm wheel offset, the axel will meet the wheel hub before it gets to the midline of the wheel, effectively lengthening the track width of the vehicle.

WOT
A abbreviation for Wide Open Throttle