One of the things that I find most interesting about automotive technology is how it advances and changes. It is also interesting that ideas from many years ago often return to favour. In this book I have therefore concentrated on core technologies, in other words how the technology works, rather than giving too many examples from specifi c vehicles. However, I have included some examples of Formula 1 technology, arguably the pinnacle of automotive engineering. Did you know that the 2011 McLaren MP4-26 F1 car is made of 11 500 components? And that’s counting the engine as one! This book is the first in the ‘Automotive Technology: Vehicle Maintenance and Repair’ series: Automobile Mechanical and Electrical Systems Automobile Electrical and Electronic Systems Automobile Advanced Fault Diagnosis The first of its type to be published in full colour, this book concentrates on essential knowledge and will cover everything you need to get started with your studies, no matter what qualifi cation (if any) you are working towards.
I have written it to be accessible for all, by sticking to the basics. As you want more detailed information, you can move on to the other two books. I hope you fi nd the content useful and informative. Comments, suggestions and feedback are always welcome at my website: www.automotive-technology. co.uk. On this site, you will also fi nd links to lots of free online resources to help with your studies. Good luck and I hope you fi nd automotive technology as interesting as I still do. This section is a general introduction to the car as a whole. Over the years many unusual designs have been tried, some with more success than others.
The most common is, of course, a rectangular vehicle with a wheel at each corner! To take this rather simple idea further, we can categorize vehicles in different ways. For example, by layout ( Figs 1.1–1.4 ), such as: front engine driving the front wheels front engine driving the rear wheels front engine driving all four wheels rear engine driving the rear wheels mid-engine driving the rear wheels mid-engine driving all four wheels. The following paragraphs and bullet points highlight features of the vehicle layouts mentioned above. Common abbreviations for these layouts are given in Table 1.1 . This is because a design with the engine at the front driving the front wheels has a number of advantages: It provides protection in the case of a front-end collision. Engine cooling is easier because of the air fl ow. Cornering can be better if the weight is at the front. Front-wheel drive adds further advantages if the engine is mounted sidewayson (transversely). There is more room in the passenger compartment. The power unit can be made as a complete unit.
The drive acts in the same direction as the steered wheels are pointing. Rear-wheel drive from a front engine was the method used for many years. Some manufacturers have continued its use, BMW for example. A long propeller shaft from the gearbox to the final drive, which is part of the rear axle, is the main feature. The propshaft has universal joints to allow for suspension movement.
This layout has some advantages: Weight transfers to the rear driving wheels when accelerating. Complicated constant velocity joints, such as used by front-wheel drive vehicles, are not needed. Four-wheel drive combines all the good points mentioned above but makes the vehicle more complicated and therefore expensive. The main difference with four-wheel drive is that an extra gearbox known as a transfer box is needed to link the front- and rear-wheel drive.
The rear engine design has not been very popular but it was used for the best selling car of all time: the VW Beetle. The advantages are that weight is placed on the rear wheels, giving good grip, and the power unit and drive can be all one assembly. One downside is that less room is available for luggage in the front. The biggest problem is that handling is affected because of less weight on the steered wheels. Flat-type engines are the most common choice for this type of vehicle. Fitting the engine in the mid-position of a car has one major disadvantage: it takes up space inside the vehicle. This makes it impractical for most ‘normal’ vehicles. However, the distribution of weight is very good, which makes it the choice of high-performance vehicle designers. A good example is the Ferrari Testarossa. Mid-engine is the term used to describe any vehicle where the engine is between the axles, even if it is not in the middle.
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