The further development of the engine 10A were 2-rotary 12A and 13A. The former was remarkable for its longevity – it was used for various models up to the middle of the 80s.

Its power for different models made from 120 hp to 130 hp at 7000 rpm and the torque – 160 -165 Nm. 12A was installed on Capella RX-2, Luce RX-4, Luce 929, Cosmo of the 3rd generation (from 1981) and the first RX-7 (Savanna). For this very engine, due to the exporting to the USA where there is a law that limits pollutant emissions, Mazda had developed a system that increased fuel efficiency and 2-component catalytic neutralizer. Later, in 1974, the exhaust system got 6 ports instead of 4 which enabled to increase the efficiency of the engine without the loss of power.

In 1982 12A was the first rotary engine to be equipped with a supercharger. Such an engine was installed on the models Cosmo RE and Luce 929. Moreover, Cosmo RE was the first model to feature admission and 2 injectors for each work chamber.

The engine 13B (power - 135 hp, torque – 190 Nm) was installed on Roadpacer (Luce) AP, Luce Legato (929L) and Parkway 26. The last model was the first bus with a rotary engine. Afterwards 13B got a supercharger and its power increased to 180 hp and torque – to 250 Nm. These engines were installed on Cosmo, Luce 929 until 1991. In 1989 there appeared a turbo-compressor with 2 independent admissions – the prototype of the modern turbine with variable geometry. The power increased to 185 hp and the torque increased on low turns. This engine was installed on RX-7 of the second generation.

In 1990 Mazda was the first company to apply a pair of sequentially installed turbo superchargers (the system Sequental Twin-Turbo) to the engine 13B-REW (REW – Rotary Engine Twin-Turbo) and to the 3-rotary 20B-REW. On low turns only one turbine functioned, and on high both the turbines increased the power of the engine. Besides, 2 working turbines decreased the backpressure of exhaust gases – this increased the smoothness of the engine immensely. The first serial 3-rotary engine in the world - 20B-REW – was installed on the coupe Eunos Cosmo and handed the unbelievable for Japan 280 hp at 6500 rpm and 410 NM at 3500 rpm. The cult, incredibly beautiful Mazda RX-7 of the third generation was equipped with 13B-REW. It was a little weaker – 255 hp and 300 Nm, but after modernization in 1998 the power increased to 280 hp.

The idea of a multi-rotary engine got its application in auto sports. June 23, 1991 the prototype Mazda 787 B equipped with the 4-rotary engine R26B won one of the most prestigious races in the world – the Le-Mans race. This was the triumph of a rotor. Nevertheless, the following year the organizers banned a rotary engine (there is an opinion that the decision had been made under pressure from the “whales ” of the automotive industry who stood apart from Wankel’s scheme).

The next stage of the development of Mazda’s rotary engines – 2-rotary Renesis, which is installed on the modern RX-8. This engine is considerably different from the one installed on RX-7. The top variant of Renesis features 6 admission ports with side placement.

Moreover, Mazda has invented sealing with sharp edges, that prevents gas penetration between the admission and exhaust ports. This engine is remarkable for its smoothness of work up to the highest turns, efficiency and low pollutant emissions. At 2×654 cm3 the engine gives out from 192 to 250 hp and 211-222 Nm (depending on the modification). It goes without saying that for average 1.30liter piston engines such characters are unachievable.

The History of Mazda Rotary Engine. Part 1

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Last year Mazda celebrated the 40th anniversary of the release of the first serial automobile with a rotary engine. This engine is also called the Wankel engine.

Felix Wankel, a German engineer and inventor, was born in the town of Lare on August 13, 1902. He was brought up in a poor family and had to leave school to become a pupil of a bookseller. He read a great number of books on engineering, mechanics and car-building. However, entering a university afterwards, Wankel was dismissed due to poor progress in physics.

There is a version that the idea of a rotary engine was born in Wankel’s head in his sleep when he was 17. He dreamed that he was driving to a concert in his own car and boasted to his friends that the car was equipped wit an engine invented by himself. The engine was of a new type – half piston half turbine. Wenkel got up with a scheme of a completely new engine in his head. He intuitively felt that 4 strokes of an engine - admission, compression, combustion and exhaust – could be carried out through rotation. This idea was the base for the creation of the rotary engine.

In 1923 Felix Wankel got down to work in his own lab. During WWII his engines got support from the government, and right after the war Wankel founded the Technical Institute of Application-Oriented Research, where he continued working on his engine. Later he was joined by the motorcycle company NSU, which even before the collaboration with Wankel had created a rotary engine for a motorcycle. The first automotive rotary engine DKM was created by the engineer in 1957. The basic parts of the engine were a trigonal rotor and a trochotron body which is used in this type of engines even today. Still, the construction with a rotating body was too complicated and one year later there appeared the new model KKM 400 with a stationary body, fluid cooling system. This very model is the prototype of the modern rotary engine.

In 1959 NSU decided to reduce the rotary program. But the idea had already possessed the minds of people all over the world – over 100 companies were eager to buy the groundwork of NSU (including 34 Japanese companies). Mazda was represented by Zunezi Mazuda. The negotiations ended up by signing the agreement in 1961. Here is the point where the rotary history of Mazda starts. Mazda is the only automotive company that produces serial cars with rotary engines. A group of engineers was sent to NSU where it got KKM 400 into possession.

At the beginning of the 60s Mazda constructed 3 types of rotary engines – 2-, 3- and 4-rotor. The NSU prototype worked well only on high turns. On low turns the vibration was very considerable which lead to fast wearing of engine case. Moreover, the engine had a very modest torque and was extremely oil-consuming due to bad sealing of the top of the rotor.

The first bi-rotary engine L8A was installed on the specially designed prototype Cosmo Sport L402А (capacity – 399 cm3). In December 1964 another engine was created – 3820 (2 x 491 cm3). This engine was the base of the first serial bi-rotary engine L10A.

In May 1967 Mazda started selling its model Mazda Cosmo Sport with 100 hp at 7000 rpm. The engine was equipped with new sealing made of pyrolitic graphite. Each work chamber featured 2 ignition sparks. In 1968 the model Cosmo Sport took part in the endurance race Marathon de la Route in Nurnburgring where it took the 4th place. The engine 10A in the deforced mode (to 100 hp) was installed on the model Familia R100, and in the 105-hp – on Savanna RX-3.

Let’s Belt Up! What for?

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Once, the Canadian hockey players played without helmets scaring their opponents with their “hot heads.” Today, though, passengers scare us with their “unbelted” sight - moreover, both passengers and drivers do their best.

But let’s find out whom they try to scare? The employees of hospitals or morgues?

It looks like motorists have split into several groups:

1. The ones who always belt up no matter where they seat (I mean either a driver or a passenger)
2. The ones who never belt up. They usually motivate it by the high class of their driving mastery and the silly legend that safety belts are the only dangerous thing in an accident
3. The ones who belt up time after time – in town – never, out of town – seldom

If we look a little closer we will easily find out that under these groups fall certain types of people. Or even vise versa – certain automobiles.

Let’s take, for instance, old cars. People seldom belt up in them for 2 basic reasons: the safety belts are definitely out of order due to the age of the car or they are so dirty that it is disgusting even to touch them not to speak of making them touch the clothes.

In new cars in $12-20 000 price range, passengers belt up more frequently – moreover, here you can encounter belted up youth. Life is beautiful, job – amazing, why risk it all? The situation is even more peculiar in the more expensive auto market segments. The owners of SUVs feel safe and rarely belt up and the owners of extremely expensive sport cars are completely sure that any situation is under their control – so they hardly ever belt up.

A number of manufacturers who fight for the safety of their clients make up special reminders for drivers in the form of annoying beepers and buzzers. But the thought is ahead of the progress: a safety belt is behind a seat – looks like a real way out. The electronics is calm and nothing rubs the belly. Of course, there are cars like Volvo, the drivers of which are simply “bound” with belts, but they are more of an exception.

The cars with the sticker “Street Racing” stand out in a crowd – the brave bodies of their owners hidden behind tinted glass reject all the safety features.

The Secret is in a Gear-Box. Gear World. Part 2

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Automatic with Positive Blocking

The more advanced automatic transmission learned to “lock” the hydraulic coupling at the higher gears and gave all the controlling functions to the electronics. The fast electronics and hydraulics were able to restore that old “steel” link in an automatic transmission inherently repeating the ancient algorithm of a simple mechanic transmission. This is the way many modern Mercedes transmission work. This was the first attempt to return to the “mechanic” algorithm.

Automatic with positive shifting

Automotive sportsmen and just “hot heads” who didn’’t want to “pull the lever” all the time demanded a more lively shifting from an automatic transmission. So there appeared automatic transmission with positive shifting. Initially – with a special sector of the lever, later – with levers and buttons on the steering wheel. In substance, it is the same automatic transmission, but with a possibility of the driver’s interference into the work of the system.

Stepless transmission

Stepless transmission (continuously variable transmission (CVT) or progressive transmission) means constantly shifting gear ratio. Pay attention to the fact that it shifts steplessly. It just means that such a scheme enables not to change the engine turn from the beginning of the acceleration to the max speed. The fist serial CVT transmissions were introduces by DAF in 1958. A dozen years ago such a technology was quite rare. But at the end of the 90s – looked like a real “burst-out”. A CVT under the cowling of Honda, Audi A6, Nissan Murano or Mercedes B-klasse is no longer a wonder.

Robotic Mechanics

With the development of the automatic transmission, the mechanics hasn’t been forgotten. There appeared a real mechanic gear-box with high-end hydro- (like in Audi A2) or electric drive (Peugeot 1007) and the “brain” automatically calculated all the algorithms and torque. The majority of robotics are slow. The only exceptions are AllShift by Mitsubishi and extra-fast SMG by BMW (M5 and M6).

DSG (now S-Tronic)

It seems quite strange why such a progressive idea has been realized only recently by the engineers of VW and Audi. DSG stands for Direct Shift Gearbox (German: Direkt Schalt Getriebе). The idea is as simple as possible: two gear-boxes and two clutches in one body. However, the double DSG works in oil like the automatic transmission. Moreover, DSG has one obvious disadvantage – it cannot “jump” over the fixed gears.

Hybrid Transmissions

The surprise sprang up in the serial Toyota Prius and Lexus RX 400h. Two types of fuel – petrol and electricity – unifying into a single stream just before the driving axle of these cars simply displaced a gear-box. There is no gear-box as there is no clutch. The only thing that remained is a simple planetary differential (redirecting the power stream like a bathroom mixer). The electronics rules the process and all the possible “skidding” is killed by a electromagnetic field.

The Secret is in a Gear-Box. Gear World. Part 1

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Transmission. What is it for? And what kinds of transmission there exist? And in your car what that stick with a comfortable knob between the front seats is attached on the other end?

Instead of a rubber belt, the modern devices are equipped with a chain. The force is transmitted through steel in special oil.

The conditions of work of the modern transmissions are so diverse that sometimes there are more than one kind of grease inside a single aggregate.

The smallest and the most reliable were and are simple mechanic transmissions.

Everything is so simple, you say. Transmission can be either mechanic or automatic. Accordingly, there are three or two pedals in the car. And you will be correct, but only partly. Due to the modern technologies these two “branches” of transmission that seem to be different in the essence, nowadays are almost molded into one single device. Automatic, by the way of controlling, but, at the same time, mechanic by construction. Moreover, there appear new types of mechanisms where there is no actual shifting process as there are no usual gears. They are replaced by a belt or a variation chain.

But the real opponent of a gear-box are the cars with alternative energy source. Electromobiles don’t need transmission, but even hybrid schemes that transmit the power of the engine with electro-power don’t need additional speed changers (which is a gear-box). It is obvious.

Does it mean that transmission is on its way out? And the entire struggle to create such masterpieces as DSG, SMG and CVT are in vain? No way! It just means that each car for a definite market niche (in strict accordance to the demand) has its own transmissions line.

Simple mechanics

In mechanic transmission, besides the moments of fully pressed clutch and “neutral” there is strict and “naturally steel” connection of the transmission from the engine to the tires. To cut the long story short, there is only a primitive gear shifting mechanism and all the work of shifting gears is laid upon your shoulders. Nevertheless, such a simple construction has 3 obvious advantages. They are:

• Reliability
• Cheapness
• Fuel Economy

Simple Automatic

In this type of transmission there is no steel connection. Instead of clutching from your foot there have appeared hydraulic coupling. All the procedures are carried out there. Moreover, the car got not that vulnerable to accelerating teaching its owner to “tap” on the pedal. At the same time, an automatic transmission has always meant less “liveliness” of the car and higher cost and weight. The more powerful the car was, the more these features were obvious.

What’s Going on in the Automotive Word

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