PRESELECTOR GEARBOX

-preselector gearbox is a type of manual gearbox


- manual shift lever is used to "pre-select" the next gear to be used, then a separate control (a foot pedal) is used to engage this in one single operation, without needing to work a manual clutch.


-Most pre-selector transmissions avoid a driver-controlled clutch entirely, some use one solely for starting off.

advantages:

• Fast shifting, with only a single operation. This requires less skill to learn than techniques like double declutchingand it offers faster shifts when racing.
• Ability to handle far more engine power, with a lighter mechanism.

The Wilson gearbox offers these:

• Their friction components are brakes, rather than clutches. These are simpler to engineer, as the wear components can be arranged to not be the rotating parts.
• The friction wear components can be mounted on the outside of the mechanism, rather than buried within it. This makes maintenance and regular adjustment easier.

They were common on Daimler cars and commercial vehicles, Maybach, Alvis, Talbot-Lago, andArmstrong Siddeley cars as well as on many London buses


They have also been used in racing cars, such as the 1935 ERA R4D,^[1] and hillclimbing cars such as Auto Union "Silver Arrows".


Military applications included tanks such as the German Tiger I and Tiger II in World War II, through to the current tanks such asChallenger 2.

NON-SYNCHRONOUS TRANSMISSION

-A non-synchronous transmission is a form of transmission based on gears that do not use synchronizing mechanisms.

-found primarily in various types of agricultural, and commercial vehicles.

-Engineered to pull tremendous loads, often equal to or exceeding 40 tons

-Non-synchronous transmissions are engineered^[4]with the understanding that a trained operator will be shifting gears in a known coordination of timing. 

-Commercial vehicle operators use a double-clutching technique that is taught in driver's trade schools.

-The most skillful drivers can shift these transmissions without using the clutch by bringing the engine to exactly the right rpm in neutral before attempting to complete a shift, a technique called "float-shifting."

-some heavy haulers have over 24 gears that an operator will shift through before reaching a top cruising speed of 70 mph (113 km/h).

SEQUENTIAL MANUAL TRANSMISSION

- type of manual transmission used on motorcycles and high-performance cars forauto racing, where gears are selected in order, and direct access to specific gears is not possible.

- A true sequential transmission will very often use dog clutch engagement 

-Engagement using dogs only requires a very brief interruption of engine torque to complete a shift into any adjacent gear.

-This allows shifting between gears without the use of the clutch. The clutch would normally be used only for standing starts.

-On a true sequential gearbox, the shift lever operates a ratchet mechanism that converts the fore & aft motion of the shift lever into a rotary motion.

-rotary action turns a selector drum (sometimes called a barrel) which has three or four tracks machined around its circumference. 

-Running in the tracks are the selector forks, either directly or via selector rods. 

-Tracks deviate around the circumference and as the drum rotates, the selector forks running in the tracks are moved to select the required gear. 

-an additional benefit of sequential manual gearboxes is that use of the clutch via foot pedal or hand control can be minimized or completely obviated, with the clutch only used for starting from a complete stop.

-Pulling on the right-hand paddle makes an up-shift and pulling on the left-hand paddle makes a down-shift.

-paddle-shift. Instead of a manual gear lever, the driver is provided with (usually) a pair of flipper paddles on the steering wheel, rally cars often utilize just a double-acting single paddle.

- many road-car-driving enthusiasts prefer a standard manual transmission, which—with a clutch pedal and the ability to skip gears—allows more driver input and a more traditional driving experience.

MANUAL TRANSMISSION

- also known as a manual gearbox or standard transmission (informally, a "manual", "straight shift", "stick (shift)" (US), or "straight drive")

- Manual transmissions are characterized by gear ratios that are selectable by locking selected gear pairs to the output shaft inside the transmission

-Contemporary automobile manual transmissions typically use four to six forward gears and one reverse gear, although automobile manual transmissions have been built with as few as two and as many as eight gears.


-Transmission for heavy trucks and other heavy equipment usually have at least 9 gears so the transmission can offer both a wide range of gears and close gear ratios to keep the engine running in the power band.


-Some heavy vehicle transmissions have dozens of gears, but many are duplicates, introduced as an accident of combining gear sets, or introduced to simplify shifting. 


-To shift to a higher gear, the transmission is put in neutral and the engine allowed to slow down until the transmission parts for the next gear are at a proper speed to engage.


-To shift to a higher gear, the transmission is put in neutral and the engine allowed to slow down until the transmission parts for the next gear are at a proper speed to engage.


-To shift to a lower gear, the transmission is put in neutral and the throttle is used to speed up the engine and thus the relevant transmission parts, to match speeds for engaging the next lower gear.


- For both upshifts and downshifts, the clutch is released (engaged) while in neutral. Some drivers use the clutch only for starting from a stop, and shifts are done without the clutch.


-Other drivers will depress (disengage) the clutch, shift to neutral, then engage the clutch momentarily to force transmission parts to match the engine speed, then depress the clutch again to shift to the next gear, a process called double clutching. 

RADIAL TIRES

-Within the rubber are a series of plies of cord that act as reinforcement.

-made of layers of rubber and cords of polyester, steel, and/or other textile materials.

Radial tires lay all of the cord plies at 90 degrees to the direction of travel (that is, across the tire from lip to lip):

-This design avoids having the plies rub against each other as the tire flexes, reducing the rolling friction of the tire. --This allows vehicles with radial tires to achieve better fuel economy than vehicles with bias-ply tires. 

-It also accounts for the slightly "low on air" (bulging) look that radial tire sidewalls have, especially when compared to bias-ply tires.

-To add stiffness, the entire tire is surrounded by additional belts that are oriented along the direction of travel, made of tire cord.

-these belts can be made of steel (hence the term steel-belted radial) orPolyester or Aramid fibers such as Twaron and Kevlar.

-low radial tires separate the tire carcass into two separate systems:

• The radial cords in the sidewall allow it to act like a spring, giving flexibility and ride comfort.
• The rigid steel belts reinforce the tread region, giving high mileage and performance.

Each system can then be individually optimized for best performance.

ALLOY WHEEL

-made from an alloy of aluminium or magnesium.

-They are typically lighter for the same strength and provide better heat conduction and improved cosmetic appearance.

-Lighter wheels can improve handling by reducing unsprung mass, allowing suspension to follow the terrain more closely and thus improve grip

-however not all alloy wheels are lighter than their steel equivalents.

-Reduction in overall vehicle mass can also help to reduce fuel consumption.

-Better heat conduction can help dissipate heat from the brakes, which improves braking performance in more demanding driving conditions and reduces the chance of brake failure due to overheating.

-Alloy wheels are prone to galvanic corrosion if appropriate preventive measures are not taken, which can in turn cause the tires to leak air.

-alloy wheels are more difficult to repair than steel wheels when bent, but their higher price usually makes repairs cheaper than replacement.

-Most alloy wheels are manufactured using casting, but some are forged. Forged wheels are usually lighter, stronger, but much more expensive than cast wheels

SPOILER

-A spoiler is an automotive aerodynamicdevice whose intended design function is to 'spoil' unfavorable air movement across a body of a vehicle in motion.

-Spoilers on the front of a vehicle are often called air dams, because in addition to directing air flow they also reduce the amount of air flowing underneath the vehicle which reducesaerodynamic lift.

- Spoilers are often fitted torace and high-performance sports cars

-diffusion is accomplished by increasing amounts of turbulence flowing over the shape, "spoiling" the laminar flow and providing a cushion for the laminar boundary layer.

-The main design goal of a spoiler in passenger vehicles is to reduce drag and increase fuel efficiency

-Front spoilers, found beneath the bumper, are mainly used to direct air flow away from the tires to the underbody where the drag coefficient is less.

-Rear spoilers, which modify the transition in shape between the roof and the rear and the trunk and the rear, act to minimize the turbulence at the rear of the vehicle.

-Adding a rear spoiler makes the air "see" a longer, gentler slope from the roof to the spoiler, which helps to delay flow separation. This decreases drag, increases fuel economy, and helps keep the rear window clean.

-A front spoiler, or air dam, is positioned under the front bumper. shaped to reduce the airflow under the car.  Air dams increase the airflow to the radiator, reduce aerodynamic drag and reduce lift. 

LED HEADLAMPS

Automotive headlamp applications using light-emitting diodes (LEDs) have been undergoing very active development since 2004.

 Low beam, front position light and sidemarker functions are performed by LEDs; high beam and turn signal functions use filament bulbs. 

As LED technology continues to evolve, the performance of LED headlamps is predicted to improve to approach, meet, and perhaps one day surpass that of HID headlamps.^[48]

The limiting factors with LED headlamps presently include high system expense, regulatory delays and uncertainty, and logistical issues created by LED operating characteristics. 

LEDs are commonly considered to be low-heat devices due to the public's familiarity with small, low-output LEDs used for electronic control panels and other applications requiring only small amounts of light.

 However, LEDs actually produce a significant amount of heat per unit of light output. 

Rather than being emitted together with the light as is the case with conventional light sources, an LED's heat is produced at the rear of the emitters. 

Unlike incandescent and HID bulbs, LEDs are damaged by high temperatures; prolonged operation above the maximum junction temperature will permanently degrade the LEDs and ultimately shorten the device's life. 

The need to keep LED junction temperatures low at high power levels requires thermal management measures such as heatsinks and/or cooling fans which are typically quite expensive.^[49]

SNOW CONDITIONS

Not only must heat be removed from the rear of the headlamp so that the housing does not deform or melt, but heat must in addition be effectively applied to thaw snow and ice from the front lenses, which are not heated by the comparatively small amount of infrared radiation emitted forward with the light from LEDs.^[50]

LEDs are increasingly being adopted for signal functions such as parking lamps, brake lamps and turn signals as well as daytime running lamps, as in those applications they offer significant advantages over filament bulbs with fewer engineering challenges than headlamps pose.

SWING-AWAY STEERING WHEEL

-Introduced on the 1961 Ford Thunderbird


-Made available on other Ford products throughout the 1960s


-Swing-away steering wheel allowed the steering wheel to move nine inches to the right when the transmission selector was in Park, so 

as to make driver exit and entry easier.

TILT & TELESCOPIC WHEEL

TILT WHEEL-

-The tilt function helps to adjust the steering wheel by moving the wheel through an arc in an up and down motion. 


-Tilt Steering Wheels rely upon a ratchet joint located in the steering column just below the steering wheel.


-By disengaging the ratchet lock, the wheel can be adjusted upward or downward while the steering column remains stationary below the joint. 

TELESCOPIC WHEEL-

- Telescoping wheel can be adjusted to an infinite number of positions in a 3-inch range. 


- The Tilt andTelescope steering wheel was introduced as an exclusive option on Cadillac automobiles in 1965.




TILT & TELESCOPIC WHEEL -

ADJUSTABLE STEERING COLUMN

-An adjustable steering column allows steering wheel height to be adjusted with only a small, useful change in tilt. 


-Most of these systems work with compression locks or electric motors instead of ratchet mechanisms.