What Will Speed Mean In Future?

It's no secret that people love speed. If you don't agree, then just take one look at the packed stands at any race track around the country (or around the world, for that matter) and you'll find true-blue race fans watching the race. There's something almost intoxicating about speed that drives us to push harder and harder to go faster and faster. Whether it's saving a fraction of a second off of an elapsed time at the local drag strip or attempting to break the land speed record on the Formula one, pushing the upper limits of man and machine is what it's all about. Around the world you'll find kids laboring over homemade go-karts to make them go just a little faster; playing NFS series to the full extent and even grown men and women are buying expensive high-performance parts from the local speed shop to achieve the same results (just on a slightly larger scale). some people even trick-out their lawnmowers so that they'll move at speeds that far exceed highway speed limits. To put it in simple terms, speed is addictive. So one must be careful while driving at exceeded speed limits. This addiction should not cost their lives.

New Valve Timing and Lift System "Valvematic" in Toyota Avensis

Toyota announced on occasion of a Technology Seminar in Berlin that the new Avensis will be equipped with the newly developed variable valve timing and lift system called Valvematic. The innovation that further improves both fuel efficiency and performance at the same time is a combination of the already known Variable Valve Timing intelligent (VVT-i) with a new mechanism that continually varies the lift of the inlet valves in order to better control the intake air flow. 

The Valvematic is a compact system that minimises energy losses. Its design makes the application in every engine possible. The compactness of the variable arm enables the rocker shaft being placed in the same height with camshafts. Because the height of the camshaft was the same as the height of a conventional one, by introduction of a cam carrier system, the same cylinder head could be used. 

The Valvematic system consists of an actuator, which drives the control shaft, the variable valve lift mechanism for each cylinder and the cam phaser VVT-i. The electrically activated system VVT-i varies air induction by automatically adjusting the pipe length according to rpm, thus working at lower rpm and engine temperatures than a conventional hydraulic system. The variable valve lift mechanism consists of four parts: the roller arm transmits the input from the camshaft, two oscillation cams contact the roller rocker arms and the slider, which contains the helical spline, transmits the rotating power of the roller arm to the oscillating cam. The slider is connected to the control shaft and links the movement in the axis direction of the control shaft. The phase of the roller arm and the oscillation cams varies with the action of the helical spline. Because the angle of rotation of the variable arm and cam is always uniform, the range in which the roller rocker arm comes in contact with the oscillation cam changes. The cam surface of the oscillation cam consists of a no lift part and a lift part. It can change the valve lift height from 1 millimetre to 11 millimetres. 

Valve lift and valve timing are determined based on best fuel efficiency. The target throttle valve angle is calculated for optimal airflow for high performance. In order to minimise the fluctuation of the intake airflow, the actuators are continuously functioning. Further, a technique to maintain a continuous airflow was developed using modelling of induction system parts including air cleaner, throttle valve, surge tank, intake manifold, and intake valve. 

According to a company's spokesman, using Valvematic, the valve lift for best fuel economy and power across each operating range can be chosen. During light load conditions (1 millimetre valve), the intake throttle is used to more precisely control airflow volume. For medium to high loads, the intake throttle is wide open, and airflow volume is controlled by the valve lift. Pumping losses are reduced across entire load range. When combined with variable valve timing, this mechanism allows the valve opening and closing event to be controlled independently. The valve timing mechanism is driven by hydraulic oil pressure, and so exhibits some delayed response compared to the electro-mechanical actuation of valve lift mechanism. While synchronisation between valve lift and valve timing is desired for some valve overlap, delayed timing response can cause too much overlap, which has negative impact on fuel economy and drivability. In such a case, additional throttle angle is used to maintain drivability. And using the output control by the valve lift, good response in transient situation could be given because no intake volume after control mechanism. 

When applied to a 2.0-litre straight-four Naturally-Aspirated gasoline engine, Valvematic provides according to a company's spokesman up to 10 percent of fuel consumption reduction, 10 percent power output improvement, enhanced transient response and reduces CO2 emissions. It will be available from the beginning of next year in the 1.8-litre and the 2.0-litre version of the new Avensis.

Audi Introduces Compressor Supercharging

The new 3.0 TFSI engine of Audi's V6 engine range combines two technologies: gasoline direct injection and compressor supercharging. The 3.0 TFSI develops 213 kilowatts and delivers its maximum 420 Newtonmetres at 2500 revolutions per minute and maintains this constantly until 4850 revolutions per minute. The crankcase of the three-litre version is made of cast aluminium/silicon, and tips the scales at 33 kilograms. The entire engine, including the compressor, weighs 189 kilograms. Later this year the new V6 will go into production.

The compressor of the engine is so compact that it fits inside the 90-degree V of the cylinder banks, in place of the intake manifold. Because it is driven by the engine via poly-V belt, its full thrust is available from idle speed upwards. The gas paths after the compressor are very short; this means that the torque is built up quickly, even more dynamically than on a naturally aspirated engine of the same displacement. The 3.0 TFSI revs up to the maximum of 6500 revolutions per minute, achieving its rated output of 213 kilowatts at under 5000 revolutions per minute.

The engine has a compression ratio of 10.5:1. The direct injection principle is once again the key, because the intensively swirled fuel cools the combustion chamber, reducing the tendency to knock. The compressor of the new 3.0 TFSI is what is known as a Roots blower. Inside it, two four-vane rotary pistons counter-rotate at a speed of up to 23,000 revolutions per minute, with an air gap between them measuring just a few thousandths of a millimetre. The rotors can deliver 1000 kilograms of air per hour and force it into the combustion chambers at a pressure of up to 0.8 bar.

Two water-to-air intercoolers made from aluminium and connected to a separate coolant circuit are integrated into the housing. Here, the compressed and therefore heated intake air is cooled down again in order to boost its oxygen content for the combustion process.

The crankcase of the three-litre engine is made of cast aluminium/silicon and tips the scales at 33 kilograms. The entire engine, including the compressor, weighs 189 kilograms. The bore measures 84.5 millimetres and the stroke 89.0 millimetres, producing a swept volume of 2,995 cubic centimetres. Also the crankcase has been adapted to the higher prevailing pressures, all components are frictionally optimised. The two intake camshafts can be adjusted through 42 degrees crankshaft angle. In the intake ports, tumble flaps induce movement in the incoming air to promote optimum mixture preparation.

The injection system is a new design also. A common rail system with six-hole injectors injects the fuel directly into the combustion chambers at a pressure of up to 150 bar. The injectors' dynamic response permits up to three fuel injections per operating cycle across an extensive range of the characteristic map.The new 3.0 TFSI will achieve an average fuel consumption of less then ten litres per 100 kilometres in virtually all longitudinally engined models of the car manufacturer, the concept for which it is envisaged. It is designed to run on either premium or regular gasoline and complies with the future emission standard Euro 5.

The car manufacturers technology of gasoline direct injection according to the FSI principle was what made this efficiency possible in the first place. Unlike conventional concepts, it allows the compressor to be located behind the throttle valve. In view of the low density of the intake air at loads below supercharging level and when coasting, its rotors are free-running and the amount of power required to drive them is low.

How Light will the Cars be in future?

ULTRA LIGHT CAR

Light, but not small. The Loremo prototype weighs no more than a Smart Car, thanks to its materials. In the past decade, automobiles in the United States have followed the same trend as Americans' waistlines, growing bigger and bigger. We're not just talking about enormous models such as the Hummer and other full-size SUVs. Even sedans and mid-sized cars have ballooned. For instance, the 2007 Honda Accord outweighs its 1988 counterpart by almost 600 pounds. Since fuel prices have risen as well, car companies and consumers alike are scrambling to find more efficient alternatives. Much of the mainstream attention has focused on different ways to power cars, rather than altering the body. But one promising solution that researchers and manufacturers have tossed around since the mid-1990s is the concept of an ultra light car.

The term started popping up in many places in 1993 with the kick-off of the Partnership for a New Generation of Vehicles. This agreement brokered by then-Vice President Al Gore and the executives of the Big Three auto makers Ford, Daimler Chrysler and General Motors) laid out a goal to build an 80-mile-per-gallon car by 2003. One cornerstone of the alliance was researching ultra light materials, such as carbon composites and lighter steels and plastics as a way to jolt fuel efficiency. Just how light are we talking? German car startup company, Loremo, which stands for low resistance mobile, will soon put its first models on sale in Europe that weigh around 1,200 pounds (544 kilograms). To put that in perspective, that 2007 Honda Accord we mentioned earlier is 3,197 pounds (1,450 kilograms). And it's even lighter than the pint-sized, 1800-pound (816-kilogram) Smart Fotwo model. In exchange for the more svelte body, the Loremo LS gets around 120 miles to the gallon. Why does weight make such a difference? And how safe are these fitter models?

Size and Safety of Lighter Cars

The average car uses only 15 percent of its energy to actually move the vehicle and drive. Most cars on the road today lose all but that sliver of power to braking, friction, idling and having to haul piles of accessories. By slightly altering the design, prioritizing function over luxury and using lighter materials, those issues can be minimized. In fact, according to the U.S. Department of Energy, every 10 percent of weight reduction translates to a 7 percent increase in fuel economy. Thanks to that significant exchange, one of the goals outlined by the Partnership for a New Generation of Vehicles was to reduce the weight of cars by 40 percent, or around 1,200 pounds (554 kilograms). But when thinking about ultra light cars like these, it's important to differentiate between mass and weight. The mass, or sizes, of ultra light prototypes car companies have revealed aren't smaller than the average compact. Rather, the weight of the materials involved makes the difference.

Cars weigh so much because many of them are made from steel parts and sizeable engines. Ultra light future cars will be made of lightweight products including plastics, aluminum and metal composites and other hybrid materials. By adjusting the weight of the car parts, companies don't have to sacrifice size and can also use smaller engines. But what about safety? If an ultra light car rams into the side of a building, won't it crumple like a ball of paper? Well, yes, it may crumble, but its impact absorption will protect the people inside. According to the State Department, "carbon fibre depodites can absorb 12 times the energy per kilogram as steel." Researchers at MIT also have discovered clay nanotech particles that could be used to make ultra light, yet ultra-strong auto parts. By adding these tiny particles to materials, it reinforces them and forms a strengthened network for incredible durability.

For Loremo, addressing safety concerns involved creating an entirely new type of car frame. While most cars are designed to distribute impact around the passenger, the Loremo passes it under them. It does so by using a longer chassis, the frame on which the car sits, that runs along the length of the car to spread the force impact linearly. The company compares it to the same effect as striking a nail. When hit the nail doesn't break because its impact is directed along its length rather than at an angle. Also, by keeping the body close to the ground and adding air shafts that funnel air through the bottom of the car, it adds driving stability in the same way as featherweight racecars. When will consumers start to see these ultra light phenomena on the car lot? The Loremo goes into production in 2010, and depending on its reception, it could set off a domino effect.

Is It Possible to Assemble a Car With Glue

When you imagine the assembly line at an auto plant, you probably picture welding machines, rivets, bolts and screws fastening all the parts of a car together. You might be surprised to learn that many automakers are using glue to bond some parts together on modern vehicles. This isn't the kind of glue you'll find in a school kid's backpack, or the kind of car glue that you might use to assemble a plastic model -- automotive structural adhesives are advanced materials called epoxies that can be customized to bond to almost any surface and endure a wide range of temperature extremes. Many automakers, including BMW, have used automotive structural adhesives in place of bolts or welds to attach plastic cladding to vehicles.

Using glue in auto manufacturing isn't a way to cut corners or make an inferior car. Modern adhesives offer a lot of engineering advantages over traditional methods of fastening two parts together. In fact, adhesives usually form a bond stronger than the materials they're bonding together. Adhesives could be the key to building lighter, more efficient cars, and when new materials such as carbon composites are used, adhesives might be the only way to bond them as carbon fiber panels cannot be welded together. Of course, auto adhesives aren't perfect -- there are a few environmental concerns and some applications for which they just don't work very well. Which adhesives work best for the many different parts of a car? And how will the use of adhesives change the auto industry? As a result, will we see less expensive cars? If so, will they be safe? Keep reading to find out. Several engine components, such as this valve cover, are commonly secured with just a few bolts and adhesive epoxies that act primarily as a sealant.

Auto Glue

To many people, automotive adhesive on a vehicle's body panels may not sound out of the question, but what about gluing the engine? Can an auto adhesive stand up to the heat and pressures that engines are capable of producing? Yes, adhesives can be and currently are used in engines. In fact, valve covers, intake manifolds and oil pans are commonly attached using just a few bolts and an adhesive material that forms a fluid- or air-tight gasket, or seal.

Epoxies - Chemicals That Stick Together

Applying adhesive in auto manufacturing is a slightly more complicated process than just slathering on some glue and holding the two parts together. For one thing, automotive structural adhesives are made from chemicals called epoxies. An epoxy comes in two parts, a resin and a catalyst. When the two components are combined, the catalyst starts a chemical reaction in the resin, and the resin develops its bonding properties as the mixture cures. Curing times for the epoxy can range from just a few minutes to a day or even longer. In some cases, curing may be aided by baking or some other form of applied heat. Some epoxies even cure with the application of ultraviolet light. This rear window will be coated with adhesive before it's placed on a Dodge Caliber.

There are two types of epoxies commonly used: polyurethane epoxies and glassy matrix epoxies. Glassy matrix epoxies are extremely strong and rigid, and they resist shearing -- lateral separation of the bonded parts -- at very high force levels. Polyurethane epoxies are more flexible, but they break under shearing forces at much lower force levels than glassy matrix epoxies. A newer two-stage application process called synergistic rubber toughening gives high-strength epoxies greater flexibility so they are less likely to fracture under stress.

Further complicating the adhesive application process are the unique needs of an automotive production line. In some cases, adhesives must be applied to an entire section of the car in a single batch. After some additional parts are attached and bonded, the section may need to go through a cleaning and painting process before the final pieces are attached. The adhesive needs the ability to stay in place when subjected to liquid sprays, electro deposition and other assembly processes. To avoid the use of expensive pre-curing ovens, this curing ability can be built-in to the adhesive, but it requires a lot of testing and some impressive chemistry. The best place to use a structural adhesive is in a location where the primary forces are either compression, where the joined pieces are pushed together, or shear, where the force tries to slide the joined surfaces against one another, like pressing your hands together and trying to slide them apart. Structural adhesives are typically not good to use if the force acting on the joint would pull the two pieces apart as most adhesives have poor peel strength. Another poor location for a structural adhesive would be one where there are forces that would bend the joint, which could allow the joint to cleave and then peel. In addition to the epoxies, urethane foams are also used in certain areas of a car. While they do have adhesive properties, these foams are used more for their properties as sealants than as structural fasteners.

Pros and Cons of Adhesives

Using adhesives has some major advantages over other fastening methods. An adhesive distributes loads better than a spot weld or a rivet. Imagine two body panels that are attached with a few spot welds. Every time the car hits a bump, the force of the bump travels through the car. When it passes across those two body panels, the spot welds carry all the force. This leads to stress fractures in the area near the welds. An adhesive would allow the panels to be attached across a wider surface area, distributing the force in a more efficient manner. A good seam weld would accomplish the same thing, except welds are so rigid they don't transfer force very well. Adhesives, especially polyurethane epoxies, have the ability to flex and absorb some of the force, and transmit the rest of it evenly across the surface area.

This is one of the reasons airplane manufactures have been using adhesives for years. Aircraft manufacturers began using structural adhesives long before the auto industry made good use of them. Adhesives also allow for the use of lighter structural materials. Welds and bolts require thick, heavy steel pieces to anchor them. With an adhesive, thinner-grade steel can be used, or the manufacturer can switch to alternate materials such as aluminum or carbon composites. These materials can't be welded the way steel can, so adhesives are often the best option. Indian automaker Tata reduced the weight of their ultra compact Nano in part by using adhesives to attach certain body panels. Temperature does affect adhesives, but the epoxies used to assemble cars don't melt until they are heated to 400 degrees Fahrenheit (204.4 Celsius) or more, and they don't crack until they are cooled to -40 degrees Fahrenheit.

The Tata Nano uses automotive adhesives to attach body panels -- and to reduce weight. That's not to say that adhesives are without their flaws. The auto industry doesn't have a lot of long-term data on the use of adhesives, and some question their ability to stand up to 10 or 20 years of use. Structural adhesives have been used by European manufacturers for several years, so confidence is growing in adhesives' longevity. There is one potential negative side-effect of adhesive use -- more expensive repairs. If an adhesive-bonded structural part breaks, most repair shops will not have the facilities necessary to rebound the adhesive. Instead, they would have to use a pre-bonded component sent by the manufacturer, possibly forcing the car's owner to pay for more than just the broken part. A good body shop can handle a cosmetic repair by cutting away the damaged section and patching in a new part with adhesives specifically designed for this purpose.

While adhesives are gaining wider use today, their use in auto assembly is not really new. Car windshields have been held in place by polyurethane epoxies for decades, and in the last ten years or so, manufacturers such as Saturn and even BMW have attached plastic cladding to their cars with adhesives instead of bolts or welds. As auto designers explore new technologies and new materials, we may see the use of adhesives skyrocket in the next few years. Even so, there will probably always be a place on the assembly line for a welder.

Fuel Stratified Injection

Homogeneous vs Heterogeneous mix.

In case of petrol engines the air and the fuel are already mixed in the carburetor and sent to the combustion chamber for combustion .so the air -fuel ratio is same at each and every point in the combustion chamber. That is a homogeneous air-fuel mixture is burnt in the combustion chamber. But in case of diesel engines, since fuel is directly injected in to the cylinder and only air alone is coming through intake, the mixing of air and fuel will not be proper .so a heterogeneous mixture is obtained with different air-fuel ratio at different points in the combustion chamber.

Evolution Of FSI

The term FSI denotes Fuel Stratified Injection .also called as direct injection stratified charge, a brilliant technical version of advanced engine technology. FSI deals with combustion of both homogeneous as well as heterogeneous air-fuel mixtures in the combustion chamber of petrol engines. How it is possible to have both homogeneous as well as heterogeneous mixtures at the same time in the combustion chamber? We’ll see now.

FSI technology uses a high-pressure direct-injection pump to create perfect synergy between power and fuel efficiency. It makes engines cleaner, more economical and delivers peppier, more dynamic performance. In direct injection systems, fuel is injected directly into the cylinder so that the timing and shape of the fuel mist can be precisely controlled. This allows higher compression ratios and more efficient fuel intake, which deliver higher performance with lower fuel consumption. Most of the petrol engines work on the principle that an even or 'homogeneous' - mixture of fuel and air at the correct proportion is ideal for combustion. Especially if full power is required, for example when accelerating. But how much of the time are we accelerating? What happens under a trailing throttle, for example when slowing down or holding in traffic?

Engineers discovered that under those conditions having a homogeneous fuel-air mixture could be wasting energy, and thus fuel. At such times the FSI engine switches to something called a ‘’stratified’’ charge, where the injector releases a precisely-timed and directed smaller charge of fuel, creating a variable mixture of fuel and air that is richest around the spark plug, for instantaneous combustion, but that becomes leaner further away from the spark. Result? Enough power for the situation and a clean, highly efficient burn. In simple terms, this means that the driver has all the power he or she needs, whenever it is needed, but the engine smoothly and seamlessly switches to a leaner burn mode whenever the car is in a steady-state cruise or is decelerating. 

Concept of FSI Engine Operation

Precise control over the amount of fuel injected and injection timings which are varied according to the load conditions is the norm in FSI engines. Basically, the engine management system continuously chooses between three different modes of combustion: ultra lean burn combustion, stoichiometric combustion and high power output mode. Each mode is characterized by the air-fuel ratio, the amount of fuel in the air-fuel mixture; the stoichiometric ratio for petrol is 14.7 to 1 by weight, but in ultra lean mode, it could be as high as 65 to 1. These leaner mixtures than those ever achieved in the conventional engines are desired because of reduced fuel consumption.

Ultra lean combustion mode is effective under normal running conditions, when little acceleration is required. The fuel is not injected at the intake stroke but rather at the latter stages of the compression stroke, so that the small amount of air-fuel mixture is optimally placed just near the spark plug. 　This stratified charge is surrounded by mostly air which keeps the fuel away from the cylinder walls for lowest emissions. The combustion takes place in a toroidal cavity on the piston's surface. This technique enables the usage of ultra lean mixtures with very high air-fuel ratio, impossible with traditional carburetors or even intake port injection.

Stoichiometric combustion mode is activated for moderate load conditions. In this mode, fuel is injected during the intake stroke. The air-fuel mixture is homogeneous with the stoichiometric rates necessary for the catalytic converter to remove the maximum number of major pollutants viz., CO and NO_X from the exhaust gas.

In full power mode, the air-fuel mixture is homogeneous as well but contains the maximum amount of fuel that is possible to ignite without knocking out, as defined by the compression ratio of the engine. The fuel is injected during the intake stroke. This mode is activated at high load conditions and provides maximum output and torque.

Mode of Operation of FSI 

The heart of FSI, lies in the adoption of a mode known as "stratified charge", which gives the fuel-air mixture in the cylinder an extra swirl to create an electric charge (much as a thunderstorm is created) at the point where it reaches the spark plug. This allows for a leaner fuel-air mixture, using less fuel, and the excess air forms an insulating layer in the cylinder to guard against heat energy losses. Exhaust gas recirculation systems divert some of the waste exhaust gases back up for re-combustion, working with catalytic converters which process the remaining surplus harmful nitrous oxides and convert them into inert nitrogen. Besides reducing such emissions, FSI technology can reduce fuel consumption by an estimated 15 percent². The fuel injector, which shoots fuel directly into the combustion chamber, can control injection to within thousandths of a second, at pressures of up to 110 bars. As a comparison, indirect injection operates at pressures of up to 8 bars. Higher the pressure betters the efficiency.

Pros and Cons of FSI

The Merits of FSI are reduced emission, reduced fuel consumption, power on demand and reduced heat loss. The only disadvantage is during ultra-lean combustion mode, the exhaust gas temperature is high enough to account for considerable NOx emissions. However, most of this is negated by adopting “Exhaust Gas Recirculation” technique.

Latest Brake Development

There's relatively less throughout for brake discs during the past 20-30 years. The most powerful disc brakes are still ventilated, cross-drilled and made of cast-iron, although larger wheels enable larger diameter of brake discs.  For calipers, road cars today still employ single caliper per disc. Each caliper is actuated by up to 4 pistons ("4-pot") or a few racing-biased cars may even employ 6-pot calipers. The caliper is made in a single piece - so called "monobloc" - and made of aluminium.

Cast-iron, aluminum and carbon-fiber discs Obviously, cast-iron disc is the heaviest part of a brake - about 8 kg each, or 32 kg per car. Aluminium alloy discs are used in the base Lotus Elise. Though light, they were less resistant to heat and fade, thus more powerful Elises still employ conventional cast-iron disc. In contrast, carbon-fiber disc is most heat-resisting yet is by far the lightest, however, it requires very high working temperature, otherwise braking power and response will be unacceptable. (it's expensive as well) It was first introduced in Formula One, but applying to road cars seems impractical (F1 cars have warm up lap to bring the discs into appropriate working temperature), although the short-lived French sports car specialists Venturi made history by applying it to its road cars in the mid-90s.

Porsche's ceramic disc brakes Recently, Porsche introduced a breakthrough to the 996 Turbo - ceramic disc brakes. Ceramic disc is highly heat and fade-resisting. Moreover, it is just 4 kg each, or half of a conventional cast-iron disc, thus save 16 kg per car. This benefit performance as well as ride quality (because of lower unsprung weight). The ceramic disc is based on specially treated carbon-fibers that are siliconized at 1,700°C in a high-vacuum process. Accompany with a new metallic brake pad, Porsche claimed it provides superior braking power yet requires less effort, thus does not require brake assist. The pad does not absorb water, hence excellent response under wet conditions.