Posts Tagged ‘1-topics’

Some of the Physics

We know from our school days that energy cannot be created or destroyed – it changes form – Einstein

The kinetic energy of the car in motion is transferred by the brake system into heat energy when brakes are applied.

Kinetic energy E = ½mv2 (m = mass, v = velocity)

So if the weight of vehicle A is twice the weight of vehicle B in order to stop over the same distance and time, twice the amount of braking energy is required to stop the vehicle. If both vehicles had the same weight but the speed of vehicle B is twice that of vehicle A then four times the amount of braking energy is required.

Modern vehicles have disc brakes where the disc is rotating with the wheel and these are slowed down by clamping a friction material against them (Pads). The friction creates a tremendous amount of heat energy that directly relates to the weight and speed of the car. The brake system for a car is designed around creating enough friction to get the job done; by a combination of the radius at which the pads act to give leverage, the size of the calipers (the pistons give the necessary pressure), the size of the friction area (size of the pad) and the pad material. Therefore for a big heavy car that is capable of high speed you need big diameter discs to allow for a lot of leverage acting against the rotation of the wheel, you need big calipers to be able to apply a large amount of force to create friction between the pad and the disc and of course you need a large pad to give the biggest frictional area.

Regardless of the car size and braking system there has to be a way of removing the heat from the system so that it does not become overwhelmed this is usually an air flow passing through and around the system while the car is in motion.

The Problems

Under normal road conditions the time that elapses between braking is sufficient for the disc and pad cool down, however on a track with a lot of repeated hard braking the heat builds up. Two things that are undesirable can then happen, both are known as brake fade.

Pad Fade

Is where the heat pushes the pad beyond its working temperature that will cause it to start to disintegrate. The brake pedal remains firm but the vehicle does not slow effectively and speeds must be reduced.

Pedal Fade

Is where the heat transfers from the pads into the pistons in the calipers. The pistons (normally produced from aluminum) in turn transfer the heat to the brake fluid, when the brake fluid overheats it loses effectiveness and can even boil. When the fluid boils the gas created is compressible, so when the pedal is applied it softens and in extreme situations can “go to the floor” – when this starts to happen it is best to back off and let your brakes cool or they might be lost completely.

The Solutions

There are a number of solutions to avoid brake pad and pedal fade; some are more expensive than others.

• Upgraded pads (will not reduce Pedal Fade)
• Upgraded Brake fluid (will not reduce pad Fade)
• Vented discs – upgraded calipers and Pads (Expensive)
• Ducting air towards the disc and caliper (can be tricky to get right)
• Installing Titanium Brake Shims – TiBrake – between brake pad and caliper

(low cost easy to fit, will work for Pedal fade, but will not solve Pad fade)

Titanium Brake Shims – TiBrake

By inserting a thin shim of titanium (titanium has a lower thermal conductivity than other suitable materials), between the back of the brake pad and the caliper, the transfer of heat from the pad to the caliper and the fluid will be greatly reduced, so that you reduce the chance of brake fade and your brake system will last longer.
TiBrake titanium shims are cut using EDM (Electro Discharge machining) this ensures the accuracy of the cut but also unlike other cutting techniques creates no burrs, making the shims safe to handle and install. The shims are cut to suit the size and shape of the brake pad, so that the maximum barrier between the Pad and the brake fluid is achieved.

Why Titanium is the right material for a Brake shim

It provides the ideal mix between strength vs. weight, corrosion resistance and thermal conductivity
It is well known that Titanium alloys have excellent strength to weight characteristics. In fact Ti-6Al-4v (the most widely used alloy) has greater tensile strength than high strength Steel but is 42% lighter.
Titanium is inert and therefore corrosion resistant, it does not react to salt water, sunlight, or any body chemistry. This means that it is safe to handle and it won’t corrode. It is used in the offshore oil and gas industries.

Titanium has a low coefficient of thermal conductivity and a high melting point +1600 Deg C, this enables it to perform as an effective thermal barrier in a brake system.

Material Coefficient of Thermal Conductivity

Titanium (Alloy Ti-6Al-4V) 7.5
Aluminium 130 – 220
Steel 30 – 50
Copper 300 – 400
Wood 0.04 – 0.4

This is why Pan handles are made of wood

Since 1986, millions of Ford Taurus models have been sold, a testimony to a midsize sedan that offers value, good styling, plenty of interior room and reliability. During the late 1990s, an unfortunate design change turned off thousands of customers, but in recent years the Taurus has been making a come back, currently in the form of a full sedan sedan for the Ford fleet.

The 2010 model is the most dramatic update for the Taurus since its inception. Larger than ever before, Ford decided to forgo mass volume in exchange for a full size sedan segment leader, one that the automaker hopes will shine the light on the rest of the Ford line up. Judging by its looks, the all new Taurus succeeds, but it may be under the hood where the new Taurus truly shines.

Reviving The Taurus Franchise

The Taurus nearly died in 2007 when the automaker decided not to maintain production of the sedan. For years, sales had been lagging and the Taurus name no longer represented design flair, cutting edge technology or value, attributes found in the first generation model. Instead, the bulbous shaped Taurus was ugly, outdated and no longer a contender to new segment leaders, the Toyota Camry and Honda Accord.

But Ford’s new CEO, ex-Boeing chair Alan Mulally, had a different idea. Instead of dumping a damaged, but still well known product line, Mulally convinced Ford executives to rename its larger Five Hundred model the Taurus. That move allowed Ford to keep the Taurus alive long enough to bring the next generation model to the market, a new sedan introduced Summer 2009.

The 2010 Ford Taurus will not ever match the sales levels of the late 1980s and early 1990s, when the Taurus was the best selling car in America, selling more than 400,000 units annually. Instead, Ford will be satisfied if the bigger and more expensive Taurus sells at least 50,000 units during its first year with hopes of eventually peaking at 100,000 units within a few years time.

Redefining The Ford Taurus

The change in the Taurus’ direction is significant as Ford seeks to redefine what it means to be a full sized sedan, let alone what it means to be a Taurus. A five passenger model, the cockpit of the Taurus is smartly designed for the second decade of the 21st century.

Ford SYNC, a hands-free voice-activated calling, MP3 and GPS system is standard across the Taurus line. A Sony stereo provides unmatched sound while push button start is standard. Ford’s MyKey technology, which is innovative technology to track and warn teen drivers whose driving habits may put themselves in danger is also included. And, to emphasize the sedan’s sport flair, shift paddles allow drivers to have a much more engaging driving experience.

Safety features in the Taurus are abundant and include a Blind Spot Information System (BLIS) which helps drivers avoid swerving into a lane occupied by another driver, rain sensing wipers, auto high beams, rear camera and power sunshade. Side impact air bags and a safety canopy with rollover sensor is also included. Indeed, a number of the features found in the Taurus are not offered by its direct competitors but are much like what Lexus, BMW and Mercedes might offer in its similar sized sedans.

Introducing EcoBoost Technology

The Ford Taurus also helps to introduce EcoBoost engine technology which is being rolled out in select Ford and Lincoln models beginning with the 2010 model year. That optional engine, a 3.5L EcoBoost™ 24-valve DOHC V6, delivers V8 power but maintains V6 fuel economy. Indeed, with 365 horsepower and an amazing 350 lb.-ft of torque, the ginned up Taurus has power numbers rivaling some of the top sport coupes on the market. Standard engine is a 3.5L Duratec V6; both engines are paired with six-speed automatic transmissions which helps the Taurus achieve class leading fuel economy levels. Front wheel drive is standard; all wheel drive is optional.

The 2010 Ford Taurus offers so many more improvements over the 2009 and earlier models. With Ford sales now on a roll, the Taurus should contribute to Ford’s success, helping the renowned automaker find its way in a rapidly changing automotive market.

The new Bugatti Veyron can reach 200 and 300 kilo meters per hour in 7.3 seconds and 16.7 seconds respectively. The car can achieve the top speed of 407 kilo meters per hour. The starting price of the model is around $1.2 million. The 2010 Bugatti Veyron 16.4, which is yet to be released, will be the most expensive and fastest car ever produced.

Performance is the heart of the current generation Bugatti Veyron. It is equipped with array of features that include an aerodynamic monocoque body structure with rear spoiler and paneled under tray and a specially designed seven-speed gearbox. The rear spoiler in the vehicle changes the gear position automatically with respect to the speed of the car.

With the powerful engine in the vehicle, the race car can achieve fuel economy of 24 miles per gallon in the city premises, while it can achieve 35 miles per gallon on highway roads. The model is offered in full time all wheel drive.

Some of the noteworthy features in the current generation Bugatti Veyron include -

• Locking hub control,
• Front anti roll bar,
• Front springs,
• Flat performance front tires,
• Stability control,
• Front and rear vented disc brakes,
• Rack and pinion steering, and
• Bilstein rear shocks

Apart from the sporty features equipped in the car, it is also provided with the interior and exterior features like heated front seats, sport front seat, dome light, climate control, overhead console, glove box, dashboard insert, tachometer, instrument display, MP3 player, remote keyless entry, and remote fuel flap release.