16 VALVE Refers to the total number of intake and exhaust valves
in 4 cyclinder engine, 4 x 4 valves per cylinder; 2
intake valves and 2 exhaust valves. 4 valve per cylinder
engines have better efficiency. They can move more air
into the combustion chamber with smaller valve openings.
Lotus has offered 16 valve, 4 cylinder engines for use
in street cars since 1970.
ABS BRAKES Anti-Lock Braking System (ABS). Equipment that provides
skid-free braking during poor traction conditions.
ABS monitors rotation of the wheels and adjusts
hydraulic pressure automatically to the wheel(s) on
the verge of lockup. An important safety enhancement
because it controls wheel lockup and allows the
vehicle to be steered while braking.
ACTIVE SUSPENSION A computer controlled system of hydraulic rams and
valves that replaces springs and shock absorbers.
Lotus Active has been patented and has been proven in
Formula 1 competition, winning at the 1987 Monaco and
U.S. Detroit Grand Prixs. Lotus Active differs from
other systems in that there are no springs and shocks.
Hydraulic rams control all suspension movements. The
rams are controlled by a very advanced processor that
sends corrective signals to the rams about 25-30 times
per second versus 4-5 times per second on the less
ANTI-DIVE A geometry of the suspension which resists the suspension
compression under braking or cornering.
ANTI-LIFT Suspension geometry that minimizes body lift or jacking
under braking or accelerating.
ANTI-NOISE Part of the Lotus Active program. A computer controlled
sound generation system that audits and measures
cockpit background noise and produces an identical out
of phase signal to cancel the noise, thus quieting the
cockpit. Lotus has developed and patented this threshold
technology. Lotus is also the industry leader in using
passive anti-noise designs to reduce noise in vehicle
BACKBONE CHASSIS A form of aerospace monocoque chassis developed by Lotus
for passenger car use. In Lotus' street going version,
the monocoque is centrally located with space for
passengers on either side, hence the term backbone.
BALANCING The weighing and machining of major engine components to
matching tolerances, resulting in lower rotating inertia,
lower vibration levels and thus better power output. The
lack of stressing vibrations also leads to longer
BAR A measurement of absolute air pressure. 1 bar is the pressure
of air at sea level, approximately 14.7 pounds per square inch.
BLUEPRINTING Carefully matching intake and exhaust ports, and cylinder
capacities to insure maximum efficiency of airflow through
BONNET (English) The English term for the engine hood.
BOOST Refers to the increase in air pressure in the intake
manifold created by an engine driven air compressor,
such as a turbocharger or supercharger.
BOOT (English) The English term for the trunk of a car.
BRAKE HORSEPOWER (BHP) The power produced by the engine (as measured
crankshaft) that is available for driving the car. It
is called brake horsepower because the shaft power is
usually measured by an absorption dynamometer or "brake".
BUMPSTEER The tendency of a vehicle to suddenly steer towards a
bump that is encountered by one side of the vehicle. Lotus
has eliminated bumpsteer by careful placement of steering
components and by well designed suspension geometries that
nullify these effects.
CAMBER The angle of wheel as measured from the vertical plane.
A wheel with the top tilted inward has negative camber,
outward is positive.
CASTER The angle of the inclination of the steering axis of a
Cd (Drag Coeffient) Measurement of air resistance (drag). The lower the
number, the less drag that a vehicle or shape has. Lotus
designs feature good cd performance, but a small amount
of total drag is sacrificed for exceptional stability at
all vehicle speeds and conditions. The Lotus Type 14 or
Elite built first in 1957 had a cd of .29, which is still
state of the art today. This shows again how Lotus is
nearly always the pioneer in using advanced concepts in
CHAPMAN, COLIN Anthony Colin Bruce Chapman, the ACBC on the Lotus badge.
The founder of Lotus. 1928 - 1982. Considered to be the
most innovative engineer in automotive racing history.
CHAPMAN STRUT Chapman's adaptation of the strut type suspension for use
on the rear of a car.
CHARGECOOLER (Also Intercooler) A radiator that cools and therefor
recondenses the intake air that has been compressed and
heated by the turbocharger thus allowing a greater amount
of air into the engine. With more air in the combustion
chamber, the ECM can deliver more fuel and make more
power. This radiator can be either cooled by air (Elan),
or by water (Esprit).
CHASSIS The frame of a car to which the suspension, drivetrain,
and bodywork are attached.
CLARK, JIM Winner of 3 Formula One Championships, 25 Grand Prix races
and of the 1965 Indianapolis 500, driving for Lotus.
COIL SPRING A wound wire coil. Used primarily to hold the car off the
suspension. Lotus uses coil springs over shocks for their
COMPOSITE Refers to combinations of materials used to create a form,
usually advanced plastic resins and fibers such as glass, carbon
and aramid (kevlar).
CONNOLLY BROTHERS A well known and respected English Currier. This famous
company uses specially raised Swedish cowhides for their
fine leather. Lotus uses these aromatic vat-dyed hides
for their interiors.
CYLINDER LINER A cylindrical tube in which the engine piston moves up
and down. Lotus uses "wet" liners in the Esprit. Wet
liners are mounted in the block in direct contact with
the coolant. This gives improved heat transfer and thus
the potential for more power development.
DIRECT IGNITION An electronic ignition system which fires the sparkplugs
by attaching the ignition coil directly to the sparkplugs.
The ECM gives the coils the ignition signal with the
advance adjusted per engine parameters and monitored by
the knock sensor. This system eliminates the distributor
and therefore requires only periodic replacement of
DOUBLE OVERHEAD CAM A pair of rotating shafts in the cylinder head whose
(DOHC) contours, or lobes, bring about opening of an engine's
intake and exhaust valves arranged atop the combustion
chamber. A DOHC design offers optimal orientation of
valves, because the cam lobe works directly on the top
of the valve stem, eliminating slack due to pushrods
and rocker arms. Higher engine speeds are possible
with this system.
DROPHEAD COUPE (DHC) The English term for convertible. The head refers
ECLAT A 2+2 Coupe produced by Lotus from 1975 to 1982. This
vehicle was the basis for the current Lotus Excel.
ELAN The original Lotus Elan was introduced in 1962 and was
produced from 1964 to 1974. The Elan was a two seat roadster
with 4 wheel disc brakes, twin cam four cylinder engine,
4 wheel independent suspension and lightweight body. The
design brief was to create a lightweight roadster that
had excellent performance and was a fast A to B car, which
means that the Elan could cover a wide variety of roads
very quickly, with a high degree of ease and controllability.
The project code named M100 in 1987 had the same design
brief and met all parameters of the brief so brilliantly
that Lotus decided to revive the famous name and create
the 1991 Elan. According to automotive engineers, writers,
and The American Heritage Dictionary, the Elan is the
definitive sports car.
ELAN + 2 A 2+2 version of the original Lotus Elan. Produced from
1967 - 1974. Chapman's first "family sized" Lotus.
ELITE (orignal) The Lotus Type 14. A two seat coupe built by Lotus from
1957 - 1962. The Elite featured an all composite unit
body/chassis whose styling and aerodynamics are still
contemporary 30 years later. Designed by Peter
Kirwan-Taylor with an all composite monocoque, this is
the only monocoque design by Lotus not to have a
ELITE A 4 place coupe built by Lotus from 1974 - 1982. This
vehicle was the first Lotus to use the Type 907 2.0
Liter engine built by Lotus. This model won the DOM
Safety Trophy in England in 1975 for easily exceeding
all emmissions and crash regulations.
ENGINE CONTROL MODULE An advanced electronic computer which monitors
(ECM) conditions and then controls engine settings to optimize
the combustion of the air/fuel mixture. Current Lotus
cars use a very powerful Delco Unit with 32K memory.
The software (the chip) is developed by Lotus Engineering.
These Delco units are very reliable and have a self
diagnostic function that notices and stores any faults
for easy repair.
ESCORT WORLD CHALLENGE A SCCA racing series for slightly modified production
high-end sports cars. The two car Lotus race team won
4 of 8 races, two of which were 1-2 victories in 1990.
EUROPA A two place mid-engine coupe produced by Lotus from
1967 - 1974. These cars were very light and handled
brilliantly. Writers called the Europa the nearest
thing to a formula car for the street.
EXCEL A 2+2 two door coupe produced by Lotus to replace the
Eclat, built from 1983 to present. This is the first
vehicle built using the full VARI process. A normally
aspirated version of the 910S engine is used, giving
FRP Fiber reinforced plastic. Continuous mat or woven fibers
impregnated with plastic resins to form a lightweight
but extremely strong solid. These plastics are stronger
per pound than steel. Commonly used fibers are aramid
(kevlar), carbon fiber, nomex and glass. These fibers are
used alternatively to provide various levels of strength
FIBERFORM A patented process used in building composite bodies. The
process allows for the Lotus to produce extreme strong
composite forms with sharp edges by preforming the cloth
mats to their final shape before VARI molding the final part.
FIXED HEAD English term refering to a solid non-removable roof, or
FORGED ALUMINUM Here used in reference to a engine piston. A piston that
is forged is formed under tremendous pressure. Forging
creates a denser material that is much stronger but more
expensive to make.
FORMULA 1 An international racing series considered the pinnacle
of motor racing. When Chapman was directing Team Lotus,
they had the best record of any other Grand Prix Team.
FORMULA CAR A open wheeled single seat race car.
FUEL INJECTION A means of metering and distributing fuel very accurately
to an engine's combustion chambers. Fuel injectors may
inject fuel into a central housing, such as the throttle
body or directly into the manifold adjacent to each intake
port. Current Lotus models use multiport (an injector for
each cylinder) systems based on Delco components.
GROUND EFFECTS A term first coined by Colin Chapman in reference to the
use of the air flow beneath the Lotus Formula 1 race car
of 1978. The car used a specially shaped undertray to
produce incredible amounts of down pressure (vacuum) which
held the Lotus race car to pavement, and dramatically
increased cornering speeds.
HAND LAPPED VALVES Hand lapping valves assures that the critical contact
area between the valve seat and valve is perfect, thus
insuring optimum seal and gas flow.
HEADER (Equal Length) An exhaust manifold where the runners from each
are of equal length. Such a system allows exhaust pulses
to meet at the collector or single pipe in a controlled
sequence, thus enhancing cylinder evacuation and gas flow.
The Esprit Turbo SE also benefits in that the exhaust
header helps to accelerate the turbo faster, giving better
HEADLAMP (English) The English term for head light.
HEEL AND TOE A driving technique which allows the driver to downshift
and brake simultaneously. The left foot operates the
clutch and the right foot operates the throttle and brake
pedals by placing the toe on the brake and the heel upon
HOOD (English) The English term for a convertible top.
IMSA BRIDGESTONE A race series for high-end sports cars and exotics.
POTENZA SUPERCARS is the International Motor Sports Association.
INTERACTIVE WISHBONE The patented suspension system used on the front
new Lotus Elan. The system maintains precise suspension
geometry without transmitting undue road harness to the
passengers. The result is the elimination of torque steer
and bump steer, and a very comfortable ride.
INTERCOOLER See Chargecooler.
KEVLAR An advanced fiber made of aramid that has 10 times the
tensile strength of steel. Extremely strong and quite
KNOCK SENSOR Senses detonation or "ping" in the combustion
Engines run most efficiently with a small amount of
detonation. The knock sensor allows the ECM to count
the detonations and adjust the ignition advance to
an optimum level.
LATERAL ARM A suspension member connecting the upright to the chassis.
LIGHT (English) The English term for window. Rear light in English refers
to the rear window.
LOTUS OMEGA/CARLTON The Lotus Omega or Carlton is the fastest limited
four door sedan in the world. Lotus heavily modifies and
rebuilds the Vauxhall Carlton or Open Omega in sedans capable
of doing 0-60 in just over 5 seconds and with a top speed in
excess of 170 mph.
LOW PROFILE POLYESTER An advanced resin developed by Lotus Engineering
RESIN Chemical used on the Elan. Used in conjunction with
the fibreform process, it allows for sharp design creases
that were before impossible with composite parts. This resin
also allows VARI to produce parts that exhibit minimal shrinkage
during curing, giving a better quality part with better
dimensional stability and surface finish.
MID-ENGINE Refers to the location of the engine, between the front
and rear wheels. A classic placement for ultra-high
MONOCOQUE Aircraft technology, a structure where the outer skin is
carries all or the majority of the load. Modified monocoques
are used in most cars today and are called "unit body". The
Lotus version is the "backbone chassis"
NEUTRAL A term used to describe the handling of a car. Neutral means
that the front and rear wheels offer equivalent traction,
or grip, and neither is more prone to slide.
NIKASIL A permanent nickel and silicon treatment applied to aluminum.
Creates an extremely hard, wear-resistant and durable surface.
The Esprit Turbo SE has Nikasil coated cylinders.
NVH Noise, Vibration and Harshness. An aspect of vehicle design
and engineering that controls the production and transfer
of sound and vibrations through a vehicle. Lotus Engineering
is the industry leader in controlling noise and vibration
while still maintaining lightweight, efficient construction
techniques. Both the Elan and Esprit are very quiet and
powerful, while still being light and efficient.
OIL COOLER A radiator used to cool engine or transmission oil.
OVERSTEER A term used to describe the handling of a car. Oversteer
means that the rear tires of a car are more prone to slide
than the fronts. Often referred to as "Loose".
PASSENGER CELL The interior space of a vehicle where the passengers sit.
Vehicles are currently engineered so that in the case of
a crash, the engine and trunk cells will deform and absorb
the crash energy, thus protecting the passengers in the
passenger cell. Lotus uses composite bodies which enhance
this passenger cell protection, because the composte body
localises the damage and will not transmit any twisting
moment into the body. This greatly reduces the chance that
the passenger cell will be deformed and trap the occupants
in the vehicle. Lotus owners are surrounded with a cage
of kevlar, urethane, steel and aluminum.
PERIMETER FRAME The Lotus Elan was designed as a roadster. This meant
the chassis and body would have to be designed very
thoughtfully in order to provide a platform with the
proper amount of torsional rigidity. The final design
consists of the standard backbone chassis, and a large
one piece composite floorpan that incorporates the rear
wheel arches and trunk pan. To this large molding, Lotus
has bonded and riveted a series of sheet steel fixtures
that strengthen the floor and tie together the A and B
pillars, the chassis, the windshield frame and the side
door beams. This structure results in a very rigid platform
and a very safe passenger cell. The bonded steel pieces
that are attached to the floor molding and the chassis
are called the perimeter frame.
PITCH The change in attitude of a car relative to front and
rear height, for example a nose up or down attitude.
POLYMERS Refers to plastics created by chemically chaining
repeating molecules. The plastic resins in Lotus
composite structures are polymers.
PORTED The operation where the ports (intake and exhaust) of
an engine head are tuned to maximize gas flow in an
out of the combustion chamber.
RACK AND PINION A steering system with little play and very direct
steering feel. The steering wheel shaft rotates a gear
called the pinion and the rack is a cogged bar engaged
with the pinion. As the pinion turns the rack is driven
back and forth. The ends of the rack are connected to
the steering wheels via tie rods.
REVERSE LOCK A steering condition where the front wheels are pointed
in the opposite (reverse) direction of the turn. This
technique is used when rear wheel traction is exceeded.
ROLL The movement of the car as it rotates about its center
of gravity leaning to one side.
SEVEN A tube-framed aluminum-paneled 2 seat roadster produced
SUPER SEVEN by Lotus from 1957 to 1973. Subsequently licensed to
Caterham Cars, who is still producing a version of the
SHOCK ABSORBER A twin tube hydraulic unit that dampens the movement of
(DAMPER) body and suspension components.
SPORTS CAR An Automobile equipped for racing, especially an
aerodynamically shaped one - or - two-passenger vehicle
having a low center of gravity and steering and
suspension designed for precise control at high speeds
on curving roads. Ill: Original Lotus Elan (The American
Heritage Dictionary of the English Language)
SPORTS RACER Usually a 2 seat race car with enclosed wheels.
SUMP The engine oil reservior, often the oil pan.
SUPPLEMENTAL A safety restraint system which uses a inflatable bag
INFLATIBLE RESTRAINT activated by sensors placed in the front bumper.
inflated for a fraction of a second to prevent the
occupant from impacting the forward cabin. Must be used
in conjunction with a seat belt system for optimum
SUSPENSION RAFT Part of a Lotus patented suspension system used on the
Elan. Provides precise suspension location and yet provides
a comfortable ride, through the use of directional bushings.
TECH-1 TOOL A hand held electronic monitoring device to measure and
obtain data from the ECM used in current Lotus cars.
THERMAL INERTIA The water cooled chargecooler on the Esprit Turbo SE
the engine to provide a 280 bhp power peak for about 35
seconds after full throttle/boost is achieved. This is because
of the thermal qualities of the water mass in the chargecooler
cooling system. When boost is first applied and heat from
the intake is shed into the system, the water absorbs the
heat and the system gradually heats up until the heat
absorption/loss rate is equalized. Before this point is
reached, the chargecooler system has an enhanced cooling
capacity that allows a "spike" of 280 bhp. In fact, this
spike lasts for about 35 seconds in the Esprit's system,
while in an air-to-air system the spike is only a few seconds.
This gives the Esprit driver a practical 280 bhp at all
times, because 35 seconds at full throttle in an Esprit
Turbo SE translates to in excess of 150 mph, which is not
a speed used on public roads very often.
THROTTLE BUTTERFLY A flat circular plate in the intake system that is
to the accelerator pedal and controls the air flow into the
TORSIONAL STIFFNESS Usually measured in lbs-ft per degree. Refers to
of a chassis. The Elan uses the backbone chassis and perimeter
frame to provide exceptional rigidity of 6600 lb-ft/degree,
which is a new standard for open cars. The Esprit has the
kevlar and urethane rollcage that provides outstanding rigidity.
Torsional rigidity is very important in designing a chassis
with excellent ride and handling characteristics. The chassis
must be as rigid as possible and the suspension as soft as
possible. This allows the suspension to follow the road
irregularities faithfully, while maintaining good suspension
alignment. This principal is the central element to all Lotus
chassis designs and explains how Lotus vehicles exhibit world
leading handling characteristics and a highly comfortable ride
at the same time.
TRACK The measurement between the center line of the tires on
the same axle, or width of the stance.
TRAIL BRAKING A high performance driving technique where the driver tapers
off the brakes as he steers into a corner. This technique
is very valuable in high speed cornering as it allows the
driver to steer and brake simultaneously, and keep the forces
on the suspension and tires consistent at the point where
braking ends and steering begins.
TRAILING THROTTLE A handling situation usually associated with rear drive
OVERSTEER Closing the throttle applies engine compression braking and
alignment changes to the rear suspension causing the rear
tires to lose traction and slide.
TRUNION A mechanical pivot located at the lower end of the suspension
wheel upright. Known in the USA as a kingpin.
TURBOCHARGER An air compressor that forces the air/fuel mixture into
combustion chamber of an engine. The air compressor is driven
by the engine's exhaust flow acting upon a turbine. Thus the
turbocharger recaptures mechanical and thermal energy in the
exhaust that is wasted in a normally aspirated engine. Lotus
uses small displacement 4 cylinder engines with turbochargers
that produce power on demand while still being efficient.
UNDERSTEER A handling condition where the front tires are more prone
to slide than the rears. Often referred to as "Push".
UPPER BALL JOINT A mechanical pivot located at the end of the upper
VARI Vacuum Assisted Resin Injection. A patented Lotus process
for forming composite panels and bodywork with consisted
VEHICLE DYNAMICS A term used to describe the behaviour of a vehicle in
WASTEGATE An air valve used to control the boost of a turbocharger.
Controls the exhaust flow applied to the turbocharger
turbine to effectively alter the boost provided by the
WATER JET CUTTER Elan body parts are trimmed and openings are cut with
Fanuc robot that uses a computer directed water jet at
50,000 psi. This greatly reduces the time taken for these
operations and vastly improves accuracy. With the greater
dimensional stability afforded by the low profile polyester
and VARI process, this gives unmatched consistency for
composite body panels.
WEIGHT TRANSFER A shifting of gravitational force. When at rest a car's
weight is distributed over all four wheels. During braking
some of the car's weight is shifted to the front tires.
Under acceleration the weight is shifted to the rear tires
and under cornering to the outside tires.
WHEELBASE The distance between the centerlines of the front and
WINDOW LIFT The English term for the switch or mechanism used to raise
a passenger window.
WINDSCREEN (English) The English term for windshield.
YAW Yaw is a change in the direction that a vehicle is pointed
versus the direction that it is moving. High yaw rates can
become a spin, and are usually countered by steering into
the spin. A vehicle with high yaw rates can be very difficult
to control while cornering, as it will be very eager to spin.
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