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A skirt that replaces the front stone-shield of a car. The air dam helps
to redirect the flow of air around the car at high speeds which in turn
helps to create a type of suction to the road.
The amount of pressure that builds up in an exhaust system due to a restrictive
Referred to the amount of extra air (compressed air) pumped into the intake
manifold by a supercharger or turbocharger. Usually measured in psi (pounds
per square inch), inches of mercury, or bar.
Refers to the size of your piston (or bore) as compared to the length
the piston travels (stroke).
Typically rubber or polyurethane pieces that fit between two metal parts.
Bushings are used to absorb friction and noise as well as provide a cushion
between metal parts to prevent wear or breakage.
/ Adjustable Cam Gear:
The cam gear is connected to the end of the camshaft. The timing belt
connects the cam gear to the crank. An adjustable cam gear allows you
to adjust the cam without removing the timing belt.
The shape of each lobe on a camshaft. Measured in Degrees.
The angle along the vertical axis of the tire/wheel when looking at the
car directly from the front or the rear. Camber is affected when cars
are raised or lowered from stock. Negative camber is when the top of the
tire is tilted closer to the car and the bottom of the tire is tilted
outward (when looking from the front or the rear). Up to a certain degree
(no pun intended) negative camber is ok and may even be desirable.
A long thick bar in your motor (for OHC's it is located in the head of
the motor) with lobes that control the opening and closing of your valves.
Found in the exhaust system after the headers and before the muffler.
It takes hot exhaust and eliminates or reduces the harmful gases by means
of chemical reaction.
The part of the exhaust system that comes after the catalytic converter.
C/R is the difference in the volume between the combustion chamber (area
at the top of the piston when it is at TDC) and the
displacement of the piston. The higher the ratio, the more power the combusted
Connecting Rod (Conrod):
Metal rod that connects the piston to the crankshaft.
Constant Velocity joint -- a type of universal joint used in the transaxle.
They ensure that the input and output shafts are rotating at the same
The part of an engine that houses the valve train, exhaust and intake
ports, combustion chamber, distributor, spark plugs, etc. It sits on top
of the engine block.
Occurs when hot spots (caused by engine deposits) in the combustion chamber
ignites the air and fuel mixture prematurely. Also occurs after combustion
if any unburned fuel is left in the combustion chamber. Also known as
engine knock. Places great stress on the engine and leads to the destruction
of the engine if ignored.
A gearbox that allows the transfer of power from the engine to be split
into two outputs (axles) that can spin at different rates. During turns,
the outer wheel needs to spin more than the other. Without a differential,
turning would not be a pleasant experience.
Do it yourself
Double Overhead Cam -- engine designed to use two camshafts; one for intake
and one for exhaust.
All the car's parts that make it move including the engine, transmission,
differential, hub, shafts, etc.
Electronic Control Unit
Electronic Fuel Injection
The computer that receives signals from various sensors and determines
how much fuel to inject into the engine under various conditions.
A large, heavy disc that is attached to the end of the crankshaft. It
adds inertia to the engine which results in smoother power flow.
A unit of measure that is equivalent to a twisting force of one pound
placed on a one foot long lever. Used to measure torque.
The process of forcing more air into your intake which is return provides
more power. Forced Induction refers to such engine add on's as Turbo Chargers,
Super Chargers, or Nitrous Oxide.
Regulator or FPR:
An FPR is a devise that maintains a steady flow of fuel to your engine.
With out the FPR, your car may suffer leaning (not enough fuel) upon hard
acceleration which requires larger amounts of fuel than a regular steady
Pipes that direct the flow of your exhaust ports to the exhaust system.
Work such as PnP (pot and polish - not plug and play!)and 3 angle valve
jobs being done to your engine head.
A technique used by racing drivers that involves the use of all three
pedals in a manual transmission equipped automobile. During shifting,
the toe of the right foot controls the brake, while the heel of the same
foot depresses the gas pedal. The left foot, of course, depresses the
clutch. When executed properly, the effect is a smooth and efficient transfer
of power between shifts.
A unit of measure used in representing the amount of energy or power produced
by a device -- one horsepower is equal to the energy required (work) to
move a 550 pound object one foot in one second. Also equivalent to 746
(in automotive terms):
A word usually used to describe a car that has undergone an engine swap,
from a lower model to a higher model. However, a hybrid turbo can describe
a T03/04 turbo is which the T04 housing is used with the T03 turbo internals
or vise versa. Any part can be a hybrid once it has been modified by interchanging
parts to achieve a desired result.
The mixture of air and fuel that flows into the intake manifold.
A device that helps to cool a forced induction intake charge. In example,
the turbo sends the charged air to the intercooler where it cools off
then flows to the intake manifold. The purpose for cooling the intake
charge is that cool air compresses better and helps to prevent detonation.
Refers to an air/fuel mixture that has more air than fuel -- may lead
A specially designed differential that not only allows the left and right
axles to spin independently, but also has the ability to distribute the
power to each axle evenly, even if one is slipping due to the loss of
A differential that locks the two outputs (axles) together , so there
is no differential action giving you maximum traction.
The bearings in the engine block that supports the crankshaft.
Manifold Absolute Pressure sensor
Refers to an engine that does not use any form of forced induction to
achieve more performance.
A condition in which the slip angle of the front and rear wheels are the
Nitrous oxide is a compound that is made up of two parts oxygen to one
part nitrogen. A gas at room temperature and a liquid under pressure.
When heated, it breaks down into its two elements.
Brand name/logo for Nitrous Oxide Systems
A gear set in which the output shaft rotates faster than the input shaft.
Where the slip angle of the rear wheels are greater than that of the front
wheels. The rear tires lose grip before front tires do. Happens more often
in rear wheel drive cars.
Anything that robs power from the engine via pulleys (air conditioners,
alternators, power steering, water pump, etc.) and direct connection.
-- To Polish (Polished):
Smoothing an engine's interior surfaces, usually the cylinder heads, to
improve flow characteristics and/or to prevent hot spots.
-- To Port (Ported):
Resizing an opening so it is matched with a mating surface.
Usually measured in horsepower, power is proportional to torque and rpm.
An rpm range where the majority of the engine's peak power is achieved.
Usually starts at engine's peak torque and ends near the engine's peak
Shift Or Power Shifting:
Refers to shifting gears without lifting the foot off the gas pedal. Shifting
must be done quickly or the engine will rev too high. Don't let the engine
rev more than 500 rpm between shifts. Not for the uncoordinated!
Includes the engine and the transmission.
A spring that is designed to be stronger as it is compressed. If it takes
50 pounds of force to compress the spring one inch, it would take more
than 100 pounds of force to compress it an additional inch and so on.
Pounds per square inch -- used to measure pressure. The measurement process
of forced intake on forced induction cars. The higher the PSI, the more
air being forced into your intake, the faster your car will go. Also known
as boost. Normal atmospheric pressure at sea level is 14.7 psi.
The maximum recommended rpms for an engine. Refers to the upper limits
of the rpm scale where engine damage will most certainly occur -- indicated
on the tachometer by a red sector.
Refers to an air/fuel mixture that has more fuel than air -- may cause
loss of power.
Revolutions Per Minute -- how many full turns the crankshaft makes in
Abbreviation for Society of Automotive Engineers.
Honda abbreviation for Sport Induction. Si models are (with the exception
of the R-Type) the top of the line cars.
Honda abbreviation for Sport Induction Racing. SiR models are the top
of line in Japan. Once in awhile, a select number of SiR's make it to
The difference in angles between the plane of the wheel and the rolling
direction of the tire.
Single Overhead Cam -- engine designed to have one camshaft control both
intake and exhaust valves.
A wing placed on the rear hatch or trunk of a car that helps to hold down
the rear end of a car during high speed drive by creating down-force,
thus preventing the rear wheels from losing contact with the road (most
effective on cars where the rear wheels are the drive wheels).
Pipe: an exhaust system that flows from the exhaust ports to the muffler
without any interference in between such as a catalytic converter.
A condition in which you have an ideal mixture of fuel and air -- between
lean and rich. Correct stoichiometry is reached when you have 14.7 parts
of air to 1 part fuel (gasoline). Perfect combustion.
These are bars or braces that extend from one strut/shock tower to the
other above the car. The purpose is to prevent body flex during cornering.
These are bars mounted beneath the car from left wheel to right wheel,
both in the front and most cars the back. The purpose is to prevent body
roll on hard cornering which may cause you to lose control of the car.
All cars come stock with swaybars, however, upgrading to swaybars of a
thicker diameter helps to improve performance.
A method of forced induction in which air is forced into the intake manifold
via a turbine attached to the crank pulley. Although the term supercharger
describes the above, it can also be used to describe any method of compressing
air into the engine, including turbochargers!
Top Dead Center -- when a piston is at the top most position during the
compression stroke. TDC can also refer to the top most position of the
piston in the exhaust stoke, but "true" TDC is on the compression
A tendency for a car to steer to one side when power is applied. A condition
that is particular to front wheel drive vehicles.
Throttle Position Sensor. Measures the angle of the throttle plate and
sends the information to the ECU.
traction is process of your tires gripping the road. Also referred to
as "hooking up." When people say "I have no traction"
it means that when they take off from a dead start that their tires spin
instead of catching the ground and putting the car into motion
A unit that houses both transmission and differential.
The time it takes for the turbocharger to start taking effect.
A method of forced induction in which air is forced into the intake manifold
via a turbine that is powered by the exhaust from the engine.
Where the slip angle of the front wheels are greater than that of the
rear wheels. The front tires lose grip before rear tires do. The angle
of the steering wheel is greater than normal -- requires more steering
by driver. Happens more often in cars equipped with front wheel drive.
Slight understeer is actually a desired condition.
When the valves in your engine are no longer controlled by the valve springs
-- your engine is more or less toast if this occurs.
Refers to all the components that operate the valves (including the valves)
in the engine's cylinder head.
Variable Valve Timing and Lift Electronic Control
A Honda proprietary system in which cam timing, valve duration and lift
is varied according to the needs of the driver -- fuel economy (normal
driving) and power (pedal to the metal). Each cam has two profiles and
rpm determines the shifting from one profile to the other.
A device that limits the boost in a turbocharger via a valve. The waste
gate bypasses the exhaust under certain conditions. Without a waste gate,
a turbocharger will destroy an engine by over boosting the intake charge.
Wide Open Throttle - throttle is open all the way as in pedal to the metal,
let as much air into the intake manifold as possible.
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