colin chapman and automotive mass properties

COLIN CHAPMAN AND AUTOMOTIVE

MASS PROPERTIES

Brian Paul Wiegand, PE74TH SAWE International Conference on Mass Properties Engineering

Alexandria, VA, 18-22 May 2015

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THE RACE BEGINS……1928 – BORN ANTHONY COLIN BRUCE CHAPMAN.1944 – MET FUTURE WIFE HAZEL WILLIAMS.1945 – ENTERED UNIVERSITY COLLEGE OF LONDON (PART OF U of L).1946 – STARTED USED CAR BUSINESS WITH CLASSMATE COLIN

DARE.1947 – BEGAN MAKING COMPETITION CARS (LOTUS MK I) &

RACE DRIVING (ENGLISH “TRIALS”).1948 – LEARNED TO FLY, SERVED IN THE RAF, WON 2 CLASS

VICTORIES. 1949 – B. SC. DEGREE IN STRUCTURAL ENGINEERING, BUILT LOTUS

MK II.1950 – EMPLOYED BY BRITISH ALUMINUM COMPANY, WON CLASS AT

SILVERSTONE (INTERNATIONAL RACE TRACK).1951 – BUILT LOTUS MK III, PARTNERED WITH THE ALLEN BROTHERS.1952 – BUILT LOTUS MK IV, FOUNDED LOTUS ENGINEERING CO. WITH

THE ALLENS, DESIGNED MK V, BUILT FIRST “PRODUCTION” CAR: LOTUS MK VI (QUANTITY 110).

1953 – STARTED MK VII (CLAIRMONTE SPECIAL), BOUGHT OUT THE ALLENS, HIRED AERONAUTICAL ENGINEERS, STARTED LOTUS MK VIII.

1954 – WED HAZIL WILLIAMS, FINISHED MK VIII, DROVE FASTEST LAP AT OULTON PARK, WON CLASS AT SILVERSTONE.

1955 – QUIT JOB TO BE LOTUS DIRECTOR FULL TIME, BUILT MK IX & MK X.

74th SAWE International Conference

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WHY MASS PROPERTIES…

THE LOTUS ENGINEERING COMPANY WAS FOUNDED BY CHAPMAN ON 1 JANUARY 1952 WITH VIRUALLY NO CAPITAL. ENGINES, GUAGES, TRANSMISSIONS, DIFFERENTIALS, AND MOST OTHER COMPONENTS WERE PURCHASED. THE MAIN WAY THAT LOTUS VEHICLES COULD BE DIFFERENTIATED FROM OTHER VEHICLES AND GAIN A COMPETITIVE EDGE WAS THROUGH MASS PROPERTIES, AND IN PARTICULAR THE RUTHLESS PURSUIT OF MINIMUM WEIGHT.


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BESIDES MASS PROPERTIES…1. SUSPENSION

IFS & IRS SOFT SPRINGING HARD DAMPING ANTI-ROLL BARS MINIMUM CAMBER CHANGE MINIMUM UNSPRUNG WEIGHT & MINIMUM

ROTATIONAL INERTIA (MINIMUM GYROSCOPIC REACTION)

2. AERODYNAMICS MINIMUM DRAG (REDUCE Cd & FRONTAL AREA) NEGATIVE LIFT (WINGS, BODY, GROUND

EFFECT )74th SAWE International

Conference

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INITIAL WEIGHT ESTIMATE…

SINCE ENGINE WAS USUALLY PURCHASED IT WAS A “GIVEN WEIGHT”:

FOR EXAMPLE, THE LOTUS MK IX WEIGHT:

Lotus Mk IX Weight = 5 × Coventry Climax 1098cc

1080 lb = 5 × 215 lb 1080 lb ≈ 1075 lb


First Estimate of Weight = 5 × Engine Weight

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FUEL BURN EFFECT ON CG… CHAPMAN WITH REGARD TO THE

1957 MK XII F2 RACE CAR:


“Fuel comes from a 12 gallon fuel tank mounted amidships over the driver’s legs in the usual Lotus practice of minimizing the handling changes which can take place as the fuel level drops. With only this tank in the car the weight distribution is 53% on the rear wheels and 47% on the front. An [additional, for endurance races] 10 gallon tank can be mounted in the tail, which if used gives a 60/40 [rear/front] weight distribution.”

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GYROSCOPIC REACTIONS… CHAPMAN WITH REGARD TO THE

1957 MK XII F2 RACE CAR:


“I realized that the high-speed F2 car would produce a further increase in gyroscopic loading if the swing axle were retained, and as I feel that the limit must nearly have been reached I decided to adopt a fairly conventional wishbone layout. We now have double wishbone location with the front member of the top wishbone doubling as an anti-roll bar; the springing and damping still being effected by one direct acting unit.”

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MINIMUMIZING VERTICAL CG…


LATER REAR ENGINE DESIGNS OBVIATED SUCH CONTORTIONS, BUT ALLOWED CHAPMAN TO RECLINE THE DRIVER’S POSITION AS MUCH AS 55 DEGREE FROM THE VERTICAL…

…REDUCING VCG & FRONTAL AREA.

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EXTREME SEATING POSITION “I remember having great difficulty

adjusting myself to that [seat] position. The front wheels seemed much higher than eye level…”

“It was a great benefit for the designers from an aerodynamic point of view, but…it held some difficulties for the driver.” Jim Clark


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FRONT ENGINE TO REAR ENGINE


The 1960 Eighteen, the first mid-engine Lotus, represented a reluctant break with earlier Chapman design philosophy:“The rear-engine (sic) layout

offers several advantages for Formula 1…low frontal area, low center of gravity, no propeller shaft problems, and minimum power loss…The chief disadvantage…is a low polar moment of inertia.”

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LOW POLAR MOMENT OF INERTIA


By 1970, when the radical wedge-shaped Lotus 72 was introduced, the desirability of a low polar moment of inertia had been long incorporated into Chapman’s design philosophy:

TBD

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LOTUS TYPE 72


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BUT CHAPMAN’S MAIN FOCUS WAS LIGHT WEIGHT…

“Weight saving is a process which…is open to criticism if it results

in unreliability, or breakages under normal use, but there is no doubt that a well-designed and properly constructed light-weight car can stand up to very hard use.”

“Instead of reducing weight, however, it is better to design light in the first place, modifying any components which may show signs of stress during development…”

“The total weight of a racing car…is…determined by the weight of the engine; if this can be decreased by one pound then the rest of the car can be made four pounds lighter.”

“…tyres and wheels are…critical factor and their weight has a considerable influence on the car as a whole…The job of the designer is to keep the right relationship between sprung and unsprung weight…”


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WHICH WAS OBTAINED BY:


1. SIMPLEST AND MOST DIRECT DESIGN.

2. MINIMUM BODY & STRUCTURE.

3. INDIVIDUAL COMPONENTS SERVE MULTIPLE FUNCTIONS.

4. MINIMUM FUEL & OIL.

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AND RUTHLESSLY PURSUED


“A racing car has only ONE objective: to WIN races…it does not matter how clever it is, or how inexpensive, or how easy to maintain, or even how safe; if it does not…win it is NOTHING!”

“…increasing the surplus of power…over total resistance…is BY FAR the most paramount item of performance…every other consideration MUST be secondary to achieving absolute minimum dead weight.”

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CHAPMAN WOULD FREQUENTLY OVERRULE THE

JUDGEMENT OF HIS OWN STRESS ANALYSTS:…

“Designing as light as possible, then waiting for things to fail in use (there was virtually no budget for pre-production testing) so that those specific pieces would then be appropriately strengthened, was the traditional Lotus (Chapman) way of obtaining an optimum structure.”

Karl Ludvigsen


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WITH THE CONSEQUENCES…


“I was becoming unhappy about the reliability of the car. Vital bits kept falling off, like the steering wheel! He cut a lot of corners, did Colin, and made things lighter than they probably should have been.”

Cliff Allison “In one car at Monza… the mechanics found

fourteen major breaks in the chassis. I had breaks in the steering, wheels fell off, wishbones breaking, anything that could happen to a car.”

Innes Ireland

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CONSEQUENCES…


“When we first got together, Colin said ‘Mario, I always want to make a car as light as possible’. I said ‘Well, Colin, I want to live as long as possible. I guess we need to talk’.” Mario Andretti

“Did I think the Lotus way of doing things was good? No. We

had several structural failures in those cars. But at the time I felt it was the price you paid for getting something significantly better.” Dan Gurney

“I always reckoned that Colin had the ability to design a winning car. But what worried me was that it might kill me before that happened! I had all sorts of problems with Lotuses. They were all very, very light…” Cliff Allison

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…AND COST:


Stirling Moss (twice badly injured, 1960 and 1962), Alan Stacey (d. 1960), Ricardo

Rodríguez (d. 1962), Gary Hocking (d. 1962) Mike Taylor (severely injured in 1960 when Lotus 18 steering column broke in two, he

sued Lotus for damages and won), Jim Clark (d. 1968), Mike Spence (d. 1968), Bobby

Marshman (d. 1964), Graham Hill (injured in 1969, but died piloting his private plane in 1975), Jochen Rindt (d. 1970), and Ronnie

Peterson (d. 1978).

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CHAPMAN’S SUCCESS…


DUE TO:1. RUTHLESSNESS

2. CHARM AND MANIPULATION3. SELF-PROMOTION

4. FINANCIAL CHICANERY5. TECHNICAL INNOVATION

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FINANCIAL CHICAINERY


American automotive exec John Z. DeLorean established the DeLorean Motor Company with British government backing as a means to revive the impoverished Belfast area of Northern Ireland. The design errors and mismanagement regarding the production of the subsequent DMC-12 would become the stuff of case histories for business students. The prototype vehicle appeared in 1976, production began in 1981, and the company was out of business by 1983.

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FINANCIAL CHICAINERY


In 1978 Chapman agreed to partner with DeLorean and have Lotus redesign the DMC-12 vehicle. By 1981 the redesign work was finished, but an embezzlement scandal was to begin. Some $17 million (£11.5 million) in UK government funding had disappeared. Fred Bushell, Lotus CFO, would serve four years imprisonment for his role. John DeLorean would ultimately lose his personal fortune to multiple civil suits.

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TECHNICAL INNOVATION


PARTIAL LIST OF “INNOVATIONS”:

COIL-OVER-DAMPER UNIT WOBBLY-WEB WHEELS

CHAPMAN STRUTBELLCRANK SUSPENSIONALL COMPOSITE CHASSIS

BACKBONE CHASSISVARI (VACCUUM ASSISTED RESIN INFUSION)

NON-AUTOMOTIVE SPONSORSHIP IN F1GROUND EFFECTS

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NEARING THE RACE’S END…


1956 CHAPMAN CRASHES IN PRACTICE @ FRENCH GP; QUITS RACE DRIVING. 1957 LOTUS XI WINS INDEX OF PERFORMANCE @ LE MANS, MARKETS FIRST ROAD CARS LOTUS SEVEN &

LOTUS ELITE.1958 FIRST F1 RACE @ MONACO GP, LOTUS XII PLACES FOURTH @ BELGIAN GP.1960 FIRST “REAR” ENGINE DESIGN LOTUS 18, 1st LOTUS (PRIVATE ENTRY) F1 WIN @ MONACO GP.1961 INNES IRELAND SCORES FIRST TEAM LOTUS F1 WIN @ WATKINS GLEN.1963 JIM CLARK IN LOTUS 29 PLACES SECOND @ INDY 500. CLARK WORLD DRIVER’S CHAMPION, LOTUS

WORLD CONSTRUCTOR’S CHAMPION .1965 JIM CLARK WINS INDY 500. CLARK WORLD DRIVER’S CHAMPION, LOTUS WORLD CONSTRUCTOR’S

CHAMPION .1968 LOTUS IPO MAKES CHAPMAN MULTI-MILLIONAIR. WEDGE SHAPE, TURBINE POWERED LOTUS 56

DEBUTS @ INDY. JIM CLARK KILLED.1970 CHAPMAN NAMED “COMMANDER OF THE BRITISH EMPIRE” (CBE). LOW YAW INERTIA LOTUS TYPE 72

DEBUTS. JOCHIM RINDT KILLED BUT POSTHUMOUSLY WINS WORLD DRIVER’S CHAMPIONSHIP. LOTUS WINS WORLD CONSTRUCTOR’S CHAMPIONSHIP.

1971 CHAPMAN ACQUIRES MOONRAKER BOATS &TECHNOCRAFT COMPANIES.1972 EMERSON FITTIPALDI WORLD DRIVER’S CHAMP, LOTUS WORLD CONSTRUCTOR’S CHAMP.1973 FITTIPALDI & PETERSON 2nd & 3rd FOR WORLD DRIVER’S CHAMP, LOTUS WORLD CONSTRUCTOR’S

CHAMP.1976 CHAPMAN’S FATHER KILLED IN ROAD ACCIDENT.1978 LOTUS SIGNS ON TO REDESIGN DeLOREAN DMC-12. MARIO ANDRETTI WINS WORLD DRIVER’S

CHAMPIONSHIP , LOTUS WORLD CONSTRUCTOR’S CHAMP.1980 CHAPMAN BEGINS MICROLIGHT AIRCRAFT COMPANY WITH BURT RUTAN.1981 DeLOREAN WORK FINISHED, BUT DeLOREAN EMBEZZELMENT SCANDLE BEGINS.

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AT 4 AM ON THE CHILL DARK

MORNING OF 16 DECEMBER 1982

COLIN CHAPMAN WOULD CROSS LIFE’S

FINISH LINE, HIS HEART NO LONGER UP TO

THE PACE…

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Q&A

FIVE MINUTES ARE ALLOCATED FOR ASKING QUESTIONS OF THE AUTHOR

74TH SAWE International Conference on Mass Properties EngineeringAlexandria, VA, 18-22 May 2015

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Q&A: DEVELOPMENT


“Development is the last refuge of an incompetent designer” Colin Chapman

“Colin was totally uninterested in a car five minutes after it had been launched. He was a great man for proving that something could be done, but that was that.” Graham Arnold, Lotus Cars Sales Director

“Chapman wasn’t very interested in development. He would find the current situation totally boring. It was new ideas that kept him going, trying to stay ahead.” Nigel Bennett, Team Lotus Engineer

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Q&A: ENGINES


“I don’t think I want to get involved with engines, I’m not an engine man, really. Mr. Ferrari himself was an engine man; Carlo Chiti is an engine man; Tony Vandervell is an engine man, but I am a chassis man, loosely speaking. And I think good engine men don’t necessarily make good chassis men, and vice versa. Engine men feel that the way to win races is to get more power from the engine. That’s what they understand, what they like doing. I’d rather have a nice, reliable, standard engine just like everybody else and try to build a better chassis.” Colin Chapman

“Colin really didn’t know anything about engines. I sometimes think he knew less than me.”

Walter Hayes

“He (Colin Chapman) realized that until Lotus created its own engine it was never going to be recognized fully as a member of the automotive world.” Mike Warner

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Q&A: QUALITY


“We allowed the electrics to be developed on the line by the electrical fitters that were making the harnesses, fitting the lights. We never actually had a competent electrical engineer…look at all the various loadings on the circuitry and design it…We never had what I would call the correct facilities for doing our own inspection.” Mike Warner, Lotus Q/C

“Engines leaked oil prodigiously. Frames cracked apart in everyday use. Due to the car’s dense packaging and tiny footprint…service access was nightmarish. Early Elans flooded when it rained and overheated in traffic, the Webers leaked fuel directly onto the ignition system, and electrical problems were legion.” Road & Track

“Lotus engineering is the worst.” Zora Arkus-Duntov

“Lotuses are all rubbish. They always fall apart.” Tony Vandervell

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Q&A: CHAPMAN


“Colin’s mind was going 24 hours a day. He was always thinking, always probing, always asking questions. He was in a category of his own.” Mario Andretti “I think of them (concepts) in the bath, and also in the wee small hours of the morning, lying in bed…I need about five and a half to six hours sleep a night, and when I’m thinking about something I usually spend an hour or so just mulling it over.” Colin Chapman

“I think that progress comes…from a cross-pollination of ideas from other engineering fields…I like reading on a lot of subjects other than racing…I get my ideas because I take in…information and design philosophies from other fields. You got to have a pretty general sort of knowledge.” Colin Chapman

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Q&A: LIGHT WEIGHT


“The modern sports/racing car such as the Lotus is designed to be as light as possible…In this way less power is needed…With less power the engine is lighter, the transmission is lighter, and the frame that has to support those components can be made lighter. Lightness can be said to breed lightness. As opposed to the…vicious cycle we…call this the ‘benevolent cycle’, and no designer…used this technique with more success than Colin Chapman.” Colin Campbell

“I believe in getting light weight from elegance of design rather than from exotic materials…it isn’t only weight but cost as well.”

Colin Chapman

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Q&A: EFFECTIVE MASS


Wt = Weight of the vehicle (lb, kg).g = Gravitational constant, “g” = 32.174 ft/s2.I1 = Rotational inertia about front axle line (lb-ft2, kg-m2).I2 = Rotational inertia about the crankshaft axis (lb-ft2, kg-m2).I3 = Rotational inertia about transmission 3rd motion axis (lb-ft2, kg-m2).

I4 = Rotational inertia about rear axle line (lb-ft2, kg-m2). TR = Transmission gear ratio (dimensionless). AR = Axle gear ratio (dimensionless). RD = Dynamic rolling radius at drive wheels (ft, m).

colin chapman and automotive mass properties

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