Chassis Engineering is a great introduction to race car design. In a practical and down-to-earth way, it covers the fundamentals of how race cars handle and the requirements for designing and constructing a car. The book includes chapters on chassis design, suspension design, frame construction, aerodynamics and tuning. Overall it provides the reader with the foundation of how the key components of a race car work and interact together. Herb Adam's " Chassis Engineering" is a holistic "Big Picture" guide to race car handling and design.
|Published (Last):||18 June 2015|
|PDF File Size:||6.74 Mb|
|ePub File Size:||4.92 Mb|
|Price:||Free* [*Free Regsitration Required]|
The Penguin. Group USA Inc. World Wide Web site address is www. Library of Congress Cataloging-in-Publication Data. Adams, Herb. Includes index. ISBN 1. Automobiles -Performance. Tampering with or altering any emissions-control device, or modifying an emissions-controlled vehicle is in violation of federal regulations. Author and publisher di sclaim all liability incurred in connection with the use of this information.
Cover design: Beth Bender. All right s reserved. This book , or parts thereof , may not be reproduced in any form without permi ssion. Printed in the United States of America. This book is printed on acid-free paper. One area of race car performance that still seems difficult to explain is suspension and handling.
Although many enthusiasts can t ell you what changes will produce what results, they may not be able to tell you why these changes produce these results. In order to. Since not all enthusiasts have an engineering or physics background , this book will attempt to discuss suspensions and handling in terms the layperson can understand.
Good handling could be described as going around corners faster while improving driver control. Because the tires are the only. Almost all of the suspension variables are related to how well a car's tires react to the ground. Just as in the case of engine tuning, where very small changes can have a dramatic effect on horsepower output, very slight changes in the suspension of your car can have significant effects on your handling. Even a one-degree change in camber can have a measurable effect on performance, so a high degree of precision is required to set-up a suspension properly.
If the tire operates best at 40 psi, increasing the pressure to 50 psi could actually reduce its performance. Every suspension adjustment and setting has an optimum value. We know that more valve timing in an engine can increase power up to a certain point and then further increases will lose power. The same concept is true in suspension tuning. This application of engineering to the automobile chassis is a very specialized field of study, so it is not widely practiced.
The information contained in this book was accumulated over many years, the result of numerous contributions by top engineers and racers. To help explain the handling concepts, I have organized this book using the "building block" approach. The first chapters present the most basic concepts. The later chapters use these basic concepts to explain the more complicated relationships and solve common problems. The study of chassis engineering is complex and can be difficult to grasp.
Hopefully , this book will make it easier. Herb Adams. Understanding how the tires work on your car is absolutely necessary in order to.
This type of analysis is called the b l a c k - b o x m e t h o d , because we do not concern ourselves with what is going on inside the "box," or tire in this case.
Vertical Load-The input for tire performance is the vertical load, or weight, on the tire. By tuning the chassts, it is possible to adjust how this vertical tire loading will change, and by knowing how the tire will respond to the change in loading, you will be able to predict the effect of the changes.
Traction-The output of a tire from a handling standpoint is its traction or how well it "sticks" to the ground. In other words , you need to know how changes in vertical load input affect the traction output.
This changing relationship is the major reason why the study of handling is often confusing. It is not. The shape of the tire performance curve is what is important. Different tires will have performance curves with different shapes or values, but they all will have a curve that results in a smaller incr ease in traction as the vertical load is increased.
Figure 1 This is a tire performance curve. The amount attraction available from any given tire is dependent on how much weight is on the tire. As weight is increased, the traction also increases.
The important thing that must be recognized however, i s that the increa se in traction becomes less and less as the weight i s increased. By making a chart of the tire performance curve Chart it is possible to see how the cornering.
Efficiency is output traction divided. A tire's cornering efficiency reduces quickly when it is asked to support more and more. Chart Vertical Load. Wh en a tir e i s perpendi cular to th e gr ound , it has z ero camb er angl e. Thi s co ndit ion p ro vides th e bi ggest tir e patch for. Equall y import ant is that th e unit -loading on ea ch part of th e tir e pat ch camb er an gle.
Tire Factors-When analyzing your car's handling, tire factors such as contact patch, tread depth, aspect ratio, etc. These factors raise or lower the traction curve and they can cause the shape of the curve to change. When the same size and type of tire is used at all four locations, these factors affect how much traction is available.
A tire will provide the maximum traction at any given vertical load when it is perpendicular to the ground. This is called zero camber angle Figure Contact patch is the area of the Ute in direct contact with the road surface. If a tire is tilted out at the top, it has positive camber. This condition reduces the tire contact patch and the tire will not provide as much traction as when it is perpendicular.
Negative camber, when the top of the tire is tilted inward, is often dialed in to compensate for the moving or bending known as deflection of suspension parts. When it is used, the result is to have zero camber angle when maximum tire traction is needed. The Circl e of Traction concept is based on the fact that a tir e has only a certain amount of traction at any giv en time.
The Circle of Traction concept says that the amount of cornering force available for a tire will be reduced by whatever amount of the total traction is also used for acceleration or braking.
How it Works-If you c ould view the tire contact patch as it moves along th e roadway , you could see how this Circle of Traction operates.
This arrow represents the available traction and it can be pointed in any direction Figure For example, if a sample tire had lbs.
This lbs. But unfortunately, it is not. Figure 1- 3. The Circle of Traction sh ows that any given tir e ha s o nly a certain amount o f traction. This am ount o f traction can b e dir ected. If some of the total Ibs. When exiting a turn , a car. As the. Acceleration Effects-The extreme example of this condition is a car making a wheel-spinning start. If there is enough power to cause both rear wheels to. As shown in the Circle of Tra ction diagram Figure , this condition results in zero cornering power available from the tires to restrain the car from side loadings.
The results of this lack of lateral force from the tires will cause the rear of the car to "fish-tail. Figure The car is driven around the circle as fast as possible, the time is measured, and the lateral acceleration , expressed in g's, is calculated from the tim e and s ize of the circle. Braking Effects The effects of braking are similar but opposite. We know that locking the front tires. When the front. On a moving car, the distribution of acceleration, cornering and braking forces is constantly changing.
Tire and handling performance is described in terms of g-force. One g is simply the force equal to gravity here on Earth. If an object is said to weigh. If this object is subjected to a second force of 80 pounds, we would say it has an. The same lb. Many magazine road tests include a measure of a car 's cornering power, or lateral acceleration.
It is measured on a skid pad and expressed in g's.
Chassis Engineering: Chassis Design, Building & Tuning
In most forms of racing, cornering speed is the key to winning. On the street, precise and predictable handling is the key to high performance driving. However, the art and science of engineering a chassis can be difficult to comprehend, let alone apply. Chassis Engineering explains the complex principles of suspension geometry and chassis design in terms the novice can easily understand and apply to any project.
Adams Herb Chassis Engineering
Excellent resources for the doityourselfer. The only resource I have found that gives you the precise calculations to configure your own suspension. Many books or magazine articles allude to this but only this gives you the info you really need. David Dyer grew up in a coastal town in NSW, Australia, and graduated as dux of his high school in
Chassis Engineering by Herb Adams
The Penguin. Group USA Inc. World Wide Web site address is www. Library of Congress Cataloging-in-Publication Data. Adams, Herb. Includes index.