A spoiler is a device attached to an automobile whose purpose is to ’spoil’ unfavorable air movement across a body of a vehicle, when it is in motion. This can result in improved vehicle stability by decreasing lift (force pushing the car upwards when in motion) or decreasing drag (force pushing the car in a direction opposite to that of its motion) that may cause undesirable handling in a car at high speeds. Some spoilers are fixed on cars primarily for looks and styling purposes which have little or no aerodynamic benefit. In some cases, an improper after market spoiler might interfere with the car’s aerodynamics resulting in a decrease in the vehicle’s performance in terms of mileage and stability.

The main aim of a spoiler in passenger vehicles is to increase fuel efficiency and reduce drag. Vehicles can be fixed with both front and rear spoilers. Front spoilers, found beneath the bumper, are 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/the trunk and the rear, act to minimize the turbulence (flow of air which is chaotic in nature) at the rear of the vehicle.

Spoilers meant for racing cars also work on the same principle of disrupting the airflow over a moving vehicle. This disruption’s primary purpose is to reduce the amount of lift naturally generated by the shape of the vehicle while it is moving and to increase the contact between the tire and the road surface, thereby increasing traction (road grip). The increase in traction improves the stability of the vehicle when turning, braking or acceleration. Spoilers of this kind which increase downforce are majorly used in racing cars where road grip is essential.

Whenever a car purrs rather loud, or even gives an energetic note from the silencer for that, most earthlings (or Muggles as the HP fans know it) think that the car has nitrous oxide in it… only a handful of us really know about its working.

The basics: The air/fuel mixture that enters the engine (regardless of the volume) is in the ratio of about 14:1 to 15:1(14 or 15 parts of air to 1 part of fuel). Exceptions are during starting/rapid acceleration, when the amount of fuel going into the cylinder is more(16:1 or 18:1). Now, if the fuel supplied is increased for the same quantity of air, then there wouldn’t be enough oxygen for all the extra fuel to be burnt completely, which means there is wastage of fuel. The oxygen content in the air is what supports the combustion of fuel and for a given kg of fuel, there only 210 grams of oxygen(21%) and that is very limited. Where as on the other hand N2O contains about 33%. If both combine, then there would be 51% oxygen. With 51% oxygen, the amount of fuel that can be combusted completely is more than 2 times which means there is almost twice the power from the same engine.

Nitrous oxide(N20) is non-reactive with most substances. However, once the temperature or pressure is raised, nitrous oxide can become a very volatile substance. When sufficiently heated(to around 300 degrees centigrade), N2O decomposes into nitrogen gas (N2) and oxygen gas (O2). When this decomposition occurs it is a highly exothermic reaction(chemical reaction that produces a large amount of heat). Thus the liberation of oxygen is made use of to give extra power by injecting extra fuel into the cylinders and thus more oxygen = more power.

To expand the explanation a bit… Nitrous oxide is an oxidizing agent which increases an engine’s power output by allowing more fuel to be burned than would normally be the case.
(Fact: N2O can be used to increase the power from as little as 0.5 hp to as much as 3,000 hp.)

Ok, we’ve talked enough of the basic working.

Let’s talk about the nitrous purge we all drool upon… Remember the scene in ‘The Fast and the Furious’ or in ‘NFS Underground’ where the car seems to spit out gases… An electrically operated valve is used to release gaseous nitrous oxide all the way up from the storage tank to the solenoid valve or valves that will release it into the engine’s intake tract. When this happens, for a moment the liquid N2O flashes to vapor as it is released… that’s purging.

Purging is not just for show off… Purging also has a purpose.. when the engine is purged, the N2O in the bottle is exerted on to the engine air intake tract to provide just the right amount of N2O in the engine to keep the combustion uniform when the N2O system is activated. Otherwise, when the system is suddenly activated the engine tends to bog a bit until the liquid N20 reaches the air intake. How cool is that!

Nitrous (as N2O is commonly or more popularly known) comes in two types…

1. Dry system
2. Wet system

In a dry nitrous system, the manifold is kept dry, the fuel is sprayed in through the injectors and nitrous is sprayed through the mass airflow sensor (MAF). This gives the vehicle’s ECU a signal that more fuel is required as the air is colder and denser than it should be, thus fooling the system to give in some extra fuel which is burnt more efficiently through the ‘extra air’ (the 1/3 mole of extra oxygen). This is how a Dry shot System works.

The wet system, on the other hand, gives out a spray of fuel along with air to maintain the proper air-fuel mixture, thus wetting the upper intake manifold - hence its name. Wet systems are difficult to install as any intake disorder can cause a backfire and can damage the engine. They are more expensive too.

Equipments such as these can be very harmful too… if you fit it on to an incapable engine or if a novice mechanic fits it into a capable engine it can only spell ‘Disaster’ with a capital ‘D’…

You can end up breaking your (car’s) pistons or ruining its camshaft or even worse… detonating your engine altogether!

You also destroy the poor, innocent Mother Earth and all your fellow-drivers with nitrogen… a very harmful green house gas, it has 270 times the effect of carbon dioxide on producing global warming

Anyway N2O rocks…

The accelerator is a control, usually a foot-operated pedal, used to control the flow of fuel into the engine. In petrol engines, it is done either by linking it to the throttle body (fuel injected engines) or carburetor (carbureted engines). The throttle body can either be mechanically or electronically controlled.

The mechanically controlled version employs a butterfly valve which is housed in the throttle body. The butterfly valve is connected directly to the accelerator pedal by means of a cable. Thus the valve regulates the amount of air entering the engine with respect to the position of the accelerator pedal which is controlled by the driver. There are no electronic components involved.

The electronically controlled version employs a sensor that is connected to the accelerator pedal. Once the gas pedal is depressed, it converts this mechanical movement into an electronic signal and sends it to the vehicle’s computer, which in turn controls the throttle using an electronic actuator. This setup ensures optimized engine performance as the fuel metering is more precise and also results in lower emission levels. The idle control and cruise control systems are controlled by the vehicle’s computer using the same electronic throttle actuator.

In the case of diesel engines, there are no throttle plates involved. Instead, the accelerator pedal is linked to a fuel injection pump which delivers fuel into the engine by means of a fuel injector.

Any vehicle suspension that uses contained air for vehicle springing can be called air suspension. This system uses air rather than metal springs to support the vehicle on its axles or wheels.

A compressor driven either electrically or by the engine supplies pressurized air to a tank. The pressure inside this tank is maintained at a particular level. Air flows from the tank to both the front and rear suspensions through a leveling valve. The leveling valve is actuated by an arm and link rod attached to the axles. Thus the air pressure is increased or decreased accordingly by the leveling valve and thus the chassis height from the axle is varied.

The air suspension system consists of the following items

- Compressor: It compresses the air and feeds it into the tank

- Reservoir tank: It stores the compressed air.

- Unloader valve: Air passes from the compressor to the the reservoir tank through this valve.

- Isolator valve: They split the air supply to the left and right springs.

- Pressure regulator valve: It regulates the pressure of air delivered to the suspension.

- Leveling Valve: They reduce or raise the chassis height by varying the supply of air to the air springs.

This is what you should do to prepare your car for the winter:

1. Check whether the headlights, fog lights and tail lights work properly.

2. Check if the windshield does not have any minor cracks or scratches. A windshield could crack up if the heater is turned on for a long duration and it is cold outside.

3. Make sure to top up/change the oil and coolant. Check transmission, power steering, brake, radiator, and battery fluids. Change the anti-freeze after every winter.

4. Keep an emergency kit inside the car at all times and ensure that the items are replaced if used. According to experts an ideal emergency kit should have: slave, aspirin, bandage, scissors, savlon, drinking water, hard candies, food, ice scraper, a shovel, tool kit, jumper cables, prescription medicines, paper towels, and crepe bandage.

5. Top up the windshield washer fluid and ensure that the wipers work properly.

6. Get a mechanic to check the door and window linings, radiator, heater, vacuum hoses, various belts and seals. When the cold sets in, be sure to open and shut the car doors every day. This will prevent them from freezing shut.

7. If needed, put some petroleum jelly on the hinges to prevent them from shutting. If the lock on the door freezes, use a lighter to heat the key slightly and insert it in the lock.

8. Always have a map, torch light, a match box, and a candle in the glove box. Also keep a few spare blankets and towels in the back seat or the boot. Make a list of emergency numbers and keep them in a safe place inside the car.

9. Check the air in your tires frequently and maintain it as per the manufacturers specification.

An airbag, a.k.a. a Supplementary Restraint System (SRS), is a flexible membrane or envelope that prevents impact of the driver’s chest and face colliding with the steering wheel in the event of a collision. An airbag might also be installed in various other parts of the cabin to protect the passengers from severe injuries. Analysis of accidents has concluded that, in 68% of cases, an airbag provides a significant safety measure.

The system uses a number of deceleration sensors installed at the front of the vehicle to sense the beginning of a frontal impact. When there is a moderate to severe frontal crash that requires the air bag to deploy, a signal is sent to the inflator unit. An igniter begins a rapid chemical reaction generating nitrogen gas (N2) to fill the air bag making it deploy through the module cover. Airbags inflate and deflate in about 0,05 seconds. The speed of the airbag coming out of the steering wheel hub or dashboard is roughly about 220 mph.

The entire system consists of the following parts:

- A thin bag made of nylon fabric, which is folded into the steering wheel or dashboard or anywhere else in the car.

- A sensor, which instructs the bag to inflate. The sensors receive information from an accelerometer built into a microchip and thus in the event of rapid deceleration(event of collision), it informs the airbag to inflate.

- The airbag’s inflator unit. Sodium azide (NaN3) and Potassium nitrate (KNO3) react in here produce nitrogen gas. This Nitrogen gas inflates the airbag.

Derived from the German word ‘anti blockier system‘, an anti-lock braking system (ABS) is a system which prevents the wheels from locking during braking. The main aim of this system is to allow the driver to maintain steering control under heavy braking. In some cases, ABS helps to shorten braking distances.

The ABS consists of an electronic controller unit, speed sensors (either one for each wheel or one common sensor for both wheels on the same axle), hydraulic valves and a pump on the brake circuit. The controller unit monitors the rotational speeds of the individual wheels and when it senses a lock up in a particular wheel(when any of the wheels is rotating significantly slower than the others) it reduces the hydraulic pressure in the brake line of that wheel alone by the use of the valve. Thus the flow of brake fluid being delivered to the brake calipers of the locked up wheel is regulated. Now, the brakes rapidly alternate (at a rate of 15 to 30 times per second) from full pressure to full release (rapid pumping) controlled completely by the electronic controller unit and hence the driver is able to steer and keep the vehicle under control even when the brakes are fully applied.

Anti-lock braking systems were first developed for use in aircrafts and the first car they appeared on was the Ford Zodiac.

This article is the second part of a series about buying used cars. Read the first part here: Buy used cars: check list before the test drive.

Test drive things to check

1. Check if the engine is cold or not (touch the hood). If the car was parked in the same spot for a longer period of time, check for oil spots on the floor.

2. Does the engine start easy? Do you notice and strange sound when starting the engine?

3. Let the engine run for 5-10 minutes and listen to the sound. Do you notice anything weird?

4. Check the evacuation smoke while starting the engine and while the car is moving. If the smoke is black then it uses too much fuel, if it is blue (sort of), the car has an oil problem. When the engine is warm, no smoke should be clearly visible.

5. Check the oil (the oil level, carter gas) - if the is gas or you can see oil around the oil cap the engine must be repaired (it might not be worth it).

6. Check oil pressure (maximum is the best).

7. Test the acceleration. Is it linear, bumpy, and not powerful enough? Accelerate to 60km/h (40miles/h) then keep it in the 600-100km/h (40-60miles/h) for about 15 minutes. Check the engine temperature while the engine is working in full. It has to be right in the middle, not above. When the temperature goes too much above the middle then you have a problem with the cooling system.

8. Test the brakes (sudden brake and see the reaction of the car).

9. Check the gearbox: is it easy to change gears (with a stick or automatic), does it enter reverse easy, do all the gears work? Do you hear any strange noises, feel vibrations?

10. Check unusual sounds while driving (wheel bearings, poking sounds when in tight turns, vibrations, gritting sounds).

11. Check electric accessories: lights, radio, windows.

12. If at night, check if the luminosity of the lights is increasing when accelerating.

13. Look at the battery, the driving belt, cables, hoses (no cracked belts, old hoses or anything like it).

14. Check the tires to be of the same type/dimensions (they should be used the same amount on both sides of the care and of the tire. If there are different degrees of usage on the interior and exterior of the tires, the car has been involved in an accident).

15. Look at the body - hits, color variations, the line of the car seen from behind, the sides in the engine compartment should not be deformed).

16. Check if the doors shut tight and check the joints, too. If the car was hit, the doors should slam shut, they need to rise before getting shut, you can see welding, crinkling at the joints.

17. Check the serial numbers on the engine, the body, to be similar with the ones in the papers. Check any sign of welding, paint or something similar on the serial number plates that would show any change.

18. Check if the radiator is not broken.

Don’t forget, the first part of this post can be found here: Buy used cars: check list before the test drive.

What is an Accumulator:

1. An accumulator is an apparatus by means of which energy can be stored, such as a rechargeable battery or a hydraulic accumulator. Such devices may be electrical, fluidic or mechanical and are sometimes used to convert a small continuous power source into a short surge of energy or vice versa. Other examples of accumulators include capacitors, compulsators, wave energy machines, pumped-storage hydroelectric plants. The most common type of accumulator is the lead-acid battery (wikipedia)

2. A tank located in the outlet of the evaporator to receive the refrigerant that leaves the evaporator. A component used to store or hold liquid refrigerant in an air-conditioning system. This device is constructed to ensure that no liquid refrigerant enters the compressor.

3. A device that cushions the motion of a clutch and servo action in an automatic transmission.

4. A container that stores hydraulic fluid under pressure. It can be used as a fluid shock absorber or as an alternate pressure source for an ABS system.

Most common use: Car battery.

A car battery is a type of rechargeable battery that supplies electric energy to an automobile. Usually this refers to a SLI battery (Starting - Lighting - Ignition) to power the starter motor, the lights and the ignition system of a vehicle’s engine. This also may describe a traction battery used for the main power source of an electric vehicle.

Every Tuesday, you can read some interesting things from around the Web about the auto industry.

Some interesting things about Toyota

Toyota Motor Corporation was started in 1937 by Kiichiri Toyoda, under the encouragement of the Japanese government, which needed domestic vehicles.

Toyota headquarters are located in Toyota, Aichi and Bunkyo, Tokyo, in Japan.

Toyota is the world’s largest seller of cars in the first part of 2007, for the first time in over 75 years when General Motors is not the first.

Toyota, though world renowned for the cars, is still involved in textile business, making automatic looms and electric sewing machines.

Toyota is one of the companies that started the “Japanese invasion” in the auto market in the United States with small and fuel efficient cars. Among other companies there are Honda and Nissan.

Toyota produces one of the most renowned trucks/SUVs in the world: Toyota Land Cruiser. Another well-known car is, of course, the best selling hybrid car: Prius.

In 2002, Toyota entered Formula 1. The drivers for the 2007 edition are Jarno Trulli and Ralf Schumacher.

The Toyota production system:

1. Base your management decisions on a long-term philosophy, even at the expense of short-term goals
2. Create continuous process flow to bring problems to surface
3. Use “pull” systems to avoid overproduction
4. Level out the workload
5. Build a culture of stopping to fix problems, to get quality right the first time
6. Standardized tasks are the foundation for continuous improvement and employee empowerment
7. Use visual control so no problems are hidden
8. Use only reliable, thoroughly tested technology that serves your people and processes
9. Grow leaders who thoroughly understand the work, live the philosophy, and teach it to others
10. Develop exceptional people and teams who follow your company’s philosophy
11. Respect your extended network of partners and suppliers by challenging them and helping them improve
12. Go and see for yourself to thoroughly understand the situation (genchi genbutsu)
13. Make decisions slowly by consensus, thoroughly considering all options; implement decisions rapidly
14. Become a learning organization through relentless reflection and continuous improvement

Source: Wikipedia

Toyota philosophy: Zeronise consists in reducing pollution, traffic deaths and road congestion.

If you know any more interesting things about Toyota, please, let us all know by writing them in the comments below.