CHAPARRAL 2C - work leading to:-


HAP SHARP'S VICTORY at Nassau in a Chaparral 2 capped the most successful season any modern sports racing car has ever enjoyed. Having met and soundly thrashed the best European and American combinations that could be aligned against them, won almost everything in sight, and made it all look astoundingly easy besides, the men at Chaparral Cars of Midland, Texas.USA , could afford to be a little smug. But the men at Chaparral Cars; though perhaps justifiably smug, are too astute to be complacent and you may be sure their development program will be continued to assure they maintain their lead.

The remarkable racing record (see below) of the Cnaparral 2s, combined with some unusual features of the cars, has stimulated all kinds of controversy and speculation over just what the "secrets" of their success are, and Chaparral bosses Jim Hall and Hap Sharp have given all the talk additional stimulus by being reluctant to give straight answers to any but the most superficial questions about their cars and their operation. Thus has a legend grown up around these cars and their talented designer-drivers.

Like any story of real people in real places doing real things, the success of the Chaparral isn't owed to a simple secret or trick. But there are real and recognizable elements of success-making in the story.

The basic Chaparral 2 is a relatively conventional racing car in general layout: midships engine of large displacement driving through a transaxle to the rear wheels; unequal-A-arm suspension front and rear large disc brakes and a light, structurally rigid chassis enclosed by an aerodynamic body shell. Features that set it apart from its contemporaries include a chassis made up of boxes or shells, bonded to each other - there are 11 boxes in all. All Chaparral 2s have had this structure made of fiberglass, but the 2C has the same basic structure fabricated from aluminum. A fiberglass body shell has been used on all cars, its shape evolving as more has been learned about air flow and cooling requirements. An automatic transmission has been the most unusual feature of the car, and recently a driver-controlled movable spoiler has been added at the rear.

The Organization

One of the most important elements in any success story is the management personnel. Let's look at the principals:

Jim Hall.

The most important thing to know about Hall is that he is a combination of engineer and driver. Generally considered to be the No.1 driver, he also makes a very good one-man design-development team. He has been racing for almost 10 years now, and has owned and driven most of the representative sports jracing cars from Europe. He, has also raced Formula I cars on occasion and in 1963 campaigned a car for the independent British Racing Partnership team. Before building the Chaparral 2 (and Jim says it's an Arabic 2, not a Roman II), he commissioned the construction of the original Chaparral, a front-engined, Chevrolet-powered car built by Dick Troutman and Tom Barnes in Southern California. As a driver he is sensitive to the car's feel, handling, engine tune, and so forth; as an engineer (ME, Cal Tech), he is able to translate his driving impressions into logical diagnoses of what's wrong and evaluate the practical possibilities for improvement. His engineering background (plus a certain disgust for the way too many others do it), enable's him to plan a businesslike, continuing development program that is much like a scaled-down version of a passenger-car development by a major manufacturer, minus the cost considerations. He is 30.

Hap Sharp.

Sharing what appears to be equal responsibility with Hall in running the Chaparral business, Sharp seems to be the backup driver, although he has been winning most of the races lately. Of the two, Sharp is the inventor. Hall says of him, "Hap is the guy with ideas. Always has ideas. Ten a minute, nine of them bad-but one real good. And let's face it, one good idea a minute is pretty, damned unusual." Hap, who studied petroleum engineering at the University of Oklahoma (his home state), says emphatically, "I'm not an engineer." He has a broad background of racing experience and, has owned and raced both formula and sports racing cars. He is also the extrovert of the two, noisy and brash where Jim is quiet and thoughtful, but on the track he is the more conservative. A measure of the confidence he has in the Chaparral 2 is demonstrated by the fact that he drives one. And he drives on circuits he previously refused to race because he "didn't feel safe on them." He seldom dents a car, rarely puts a wheel off the road and almost never crashes. Sharp is 37 and owns two oil well drilling companies, one in Midland and the other in Louisiana.

Sandy Hall.

Jim's pretty, blonde wife Sandy figures strongly in the Chaparral organization, too. She came out to the shops a year ago to organize things. "I came out just to try to straighten out the office- Jim's desk was absolutely covered with mail-some of , it a year old. It took a while, but I managed, to get things in order. And it looks like I'm here permanently." Sandy's duties range from receptionist, to going for coffee and lunch on those pre-race days when "the boys" don't want to leave the test track, to running stopwatches on race days. And she is an excellent public-relations representative for Chaparral Cars.

The Chief Mechanics

The Chief Mechanics are a vital part of the Chaparral operation. Each is fully responsible for one of the cars, and each takes a great deal of pride in his particular car being properly prepared. Under their direction is a team of staff mechanics. The chief mechanics and their cars are: Troy Rogers-Chaparral 2, No.1 Wesley Sweet-Chaparral 2, No.2 (presently wrecked, being rebuilt) Franz Weis-Chaparral 2, No.3, Carl Schmid-Chaparral 2C Randy Gilbert-Chaparral 2B (development car, not raced. Sweet, Weis and Schmid are all ex-VW mechanics. Sharp says that VW mechanics have the most thorough training of any to be found in car dealerships. There are no prima donnas in this group, just competent men who know who the boss is.

The Facilities

Well-trained and directed as they are the Chaparral people couldn't accomplish half of what they've done without the fine physical facilities they have for testing and developing the cars. My reaction to the whole layout upon visiting the Midland plant was "This is the way it should be done, obviously. Why don't they all do this?"

Of course, not everybody can afford to run an operation like Chaparral Cars on the mere hope of winning races. Hall and Sharp had the money in the first place to set up the whole thing. By now they may be approaching a break-even point, but it took a great outlay to get it all going. A necessary addition to the mere fact that these men had money was that they wanted, in the worst way, to win. Perhaps for the glory of Texas, perhaps for their own, maybe just for fun.

Supplementing the winning monies, which, great as they are, probably don't go very far toward offsetting the costs of the operation, are direct funds and development assistance from such substantial sponsors as Firestone tires, Bosch ignition, Cox models, Shell gasoline and Koni shocks.

There are three small aluminum buildings, unmarked' but for a small label on the mailbox, just off the Rankin Highway six miles south of Midland. These are exceptionally clean and well equipped for the work done there on the cars. Building No.1 (headquarters of the plant) is used for work on the complete cars. No.2 is used for construction of components, and 3 contains the engine dynamometer.

This dynamometer is one of the finest available: a Froude, made by Heenan-Froude of Gloucester, England. Its capacity is 1000 hp, which can be absorbed at any speed from 6750 to 12,000 rpm. The adjoining instrument and control room is very neat and well set up too. Instrumentation there includes pyrometers for reading the normal test temperatures-sump oil, engine water out of block, carburetor air-plus additional instruments for nine more temperature readings that might be needed for certain tests. To have such a dynamometer room on the premises is an asset. Fine engine tuning becomes a very orderly process with this kind of equipment, not to mention the possibility of running extended durability tests on engines.

The most important, and most unusual, of Chaparral facilities is the test track, Rattlesnake Raceway. Other builders must rent a nearby track and do last-minute sorting out at the actual race scene, but not Chaparral Cars. The track is two miles around, paved, fairly smooth, and has been used for local club racing, though it was a bit narrow for that. Land around Midland is relatively flat, so there's not much in the way of elevation changes. But there is a good assortment of bends which can be negotiated by a Chaparral at speeds from 55 to 130 mph, a couple of mild grades, and a straight which permits speeds of over 160 mph.

Adjacent to the main straightaway of the track is something perhaps even 'more unusual in the sports/racing car business: a skid pad. This is a flat concrete area approximately 140 ft in diameter. On this are marked, with a white line, two .circles-one of 108-ft dia. on smooth concrete, the other of 125-ft dia. with concrete bumps of varying, but not random, heights. A sprinkler system can wet the skid pad to duplicate rain conditions.

The main purpose of the smooth 108-ft circle is to test and calibrate the suspension. It's done this way: the car is driven around the circle at full tilt about 10-12 times in one direction. This number of laps gives the driver a chance to get the feel of the car and reach an optimum cornering speed for that state of the car. He is timed by mechanics. Then the process is repeated in the opposite direc~ion around the circle.. After that, 'adjustments are made to the suspension by the mechanics. And alJ this is repeated until the best speed around, the circle is reached, for both directions.

The bumpy 125-ft circle is used for evaluating the suspension's behavior under both cornering and bump loads; it's also useful for running durability tests on the suspension and other components that might be affected by road irregularities.

The Engineering Approach

The combination of a logical, painstaking development program run by a trained engineer with adequate. and appropriate testing facilities is the best way to describe the Chaparral approach to racing cars.

Since the inception of the Chaparral 2, most of the development work has been concentrated, of necessity, on durability. Naturally, other work has continued to make the car faster and better-handling, but the bulk of the job has been the much less exciting work of making the cars live long enough to finish races. Another side of the development work, a side even less glamorous than the durability side, has been directed toward making the car as easy as possible to assemble, repair, adjust and service. Fine-tuning the suspension can be quickly carried out, for example, because of the calibrated adjustments that have been designed in. Balancing the brakes is a job that takes seconds on the Chaparral but takes minutes and sometimes hours on other cars. Anyone who has had any experience in development work will appreciate that simplicity is the most difficult characteristic to build into a basically complicated mechanism. And the Chaparral 2 has that kind of intelligent simplicity.

The Original Chaparral 2.

We asked Hall who was responsible for the design concept and execution of the original Chaparral 2. It was the result of multi-bull sessions between Hap and myself, he says. "About the time we had any reliability in the Chaparral 1, it wasn't fast enough any more. We knew we had to have a lightweight car with lots of horsepower, and that we would have to have most of the weight over the driving wheels if we were going to accelerate at 0.7 G-and we were. We didn't know much about front-wheel drive, so we decided on a rear-bias, rear-drive car. We picked Lotus-type suspension-or did Broadley have it first on his l100-cc car?-because we didn't think we could do any better than that."

The original car was designed, then, by Hall and Sharp-and built with little drafting-room work in between. In Sharp's words, "We told the mechanics to build us a piece like this-about so big-to do this job-and they'd build it." It wasn't intended to be an assembled car, Qut they did decide to use available parts wherever such parts suited the purpose. Among the purchased components used in the first car were: Chevrolet engine, Colotti gearbox, Lotus hubs, knuckles and wheels, Cooper steering, Girling brakes, modified Lotus front suspension, Lotus rear suspension.

The Chaparral Frame

The basic frame of the Chaparral 2 is a most interesting and unusual piece of engineering. It was conceived jointly by Hall and Andy Green of PlasTrend, Fort Worth. The design requirements laid down by Hall called for a maximum frame weight of 150 Ib, combined with an' axle-to-axle torsional rigidity of at least 3000 Ib-ft deg.

These weren't easy requirements to meet and, combined with the geometrical limitations imposed by such considerations as ground clearance, the provision for doors, and clearance for suspension linkages, called for a new approach to frame design.

The solution was an unusual one and certainly successful-and it's as hard to give a simple name to categorize this frame as it was to design the thing. Green, in presenting a paper on the frame to a meeting of the American Society of Mechanical Engineers, paused to define "monocoque" (literally one shell): A pure monocoque consists of shell only with no longitudinal or transverse stiffeners attached to the cell walls. The skin by itself carries all shear and bending loads. It is usually a closed tube of some sort, but there aren't many of these in actual practice." From this it is evident that there aren't any true monocoque cars. Green went on to say that if the frame must be categorized, it should be considered a set of monocoque boxes bonded together. "

The frame consists of pairs of torque boxes running down each side, connected by bulkheads at each end of the cockpit and extending at the rear to the suspension mounting points.

Made of fiberglass-reinforced plastic (FRP') in the Chaparral 2, it extends right to the car's outer contours for its outside and bottom, up to form the bottom of the door openings, inward to the engine sides and to the driver's elbow and knee in the cockpit. Thus it takes full advantage of the car's overall size to get maximum rigidity from the torque boxes (the stiffness of a torque box is proportional to its cross-sectional area) and does double duty as part of the car's outer skin.

At the time of its introduction, this frame achieved a weight saving over any other type of frame known, and in meeting the 3000 lb-ft deg requirement it was the stiffest radng-car frame in existence.

The FRP frame has also proved to be quite strong when it comes to impact: because it breaks locally and does not bend, a damaged frame can be repaired successfully. The most dramatic demonstration of this fact came at Sebring last year when Hall won the 12-hour race. with the same frame that he had crashed at Mosport the previous September.

For the 2C, an aluminum version of the same frame has been built and a further weight saving has been realized-but this does not necessarily indicate that plastic will not be used in the future.

Automatic Transmission

The idea of using an automatic transmission was concurrent with the conception of the car, but naturally this became a development program in itself and use of the automatic in racing was deferred until there was sufficient experience gained in testing. Hall and Sharp aren't saying how many failures occurred in testing, but there have been three in races. They also didn't reveal just what qualities of an automatic transmission appealed to them at the time, but we would judge that its potential reliability was one of the. most attractive characteristics. With the automatic, the drastic reduction of shock loads 'on other drive train components and the elimination of some disastrous. (to\the drivetrain) driver errors, plus the reliability of the transmission parts themselves, were important. Similar considerations have led taxi operators to make an almost complete switch to automatics-an unlikely but not ridiculous parallel.

The automatic was first used at Laguna Seca in May 1964, and then at Kent and Mosport shortly after. Nobody noticed it at first, and nothing was said to Sharp or Hall about it until Mosport, its third race. "A lot of scribes are smart-alecks-saying they can tell what kind of ignition points we're using by the sound of the engine but I never heard a word from any of them, quips Sharp, Dave MacDonald had a dice with Jim at Kent and realized something didn't sound quite right; mentioned it to Dan Gurney, and at Mosport Gurney came over and asked me what kind of transmission we were using."

By the way, the automatic (the builders still won't talk much about it) in our judgment is of an extremely simple type. It's quite compact, has a 2-speed pJanetary gearbox and what seems to be a very simple torque converter,no switch-pitch vanes or auxiliary geared turbines, and is shifted by a 2-position lever in the cockpit except when an ,automatic override forces an upshift at the engine redline. The driver generally releases the throttle momentarily for upshifts, probably to make things easier on the clutches.

Hall and Sharp like the automatic transmission from the driver's viewpoint as well as for its durability. The obvious advantage of allowing the, driver, more concentration on his cornering and maneuvering is augmented by it's desirable effect on braking: Hall says that not only is the driver able to brake more accurately because he's not shifting too, but the car's braking balance front-to-rear is easier to achieve. The reason for this latter is that, having to decide upon a braking balance that will avoid rear brake lockup under all conditions,it's easier to get a good balance with only two gearbox speeds than with four. or five, because each-change in ratio affects the rearwheel braking force quite independently of the front. And any change in braking effect from the torque converter is continuous, not stepped. Hall also says that the transmission doesn't cost him any fuel economy.

Body Shape Development

The original body design was based on some wind tunnel data, but when it was first tested qtMidland the nose got light at about 120 mph. Hence the "snowplow"modiflcation first seen at Riverside in October 1963. The Chaparrals were the first to have something like this, and it was the result of what Hall and Sharp call "fooling around" with various fixes at the test track. It did its job well under ideal, smooth-road conditions; but it was found that its effect was highly sensitive to its height from the road. Apparently it worked by keeping the air from going under the car, and with a nominal clearance of 2.5 in. from the ground, a variation of only 1 in. was too much for it to work properly.

The first major redesign of the body was a new front end, and this took care of the front-end lift problem. Then as is often the case with development programs, the elimination of one problem revealed another: now rear-end lift became a problem at speeds which couldn't be obtained before the front lift was eliminated! The solution to the new problem was a vertical lip attached to the rear of the car, in effect an air-flow spoiler.. Not an original solution, to be .sure, as Ferrari had already been using spoilers on their sports jracing cars since Sebring In March 1961. The spoiler has become a familiar appendage on contemporary sports racing cars and has already led to a styling fad in production cars. The functional spoiler is a crutch, however, and nobody building racing cars likes it; it counteracts rear-end lift but doesn't cure it at its source-not to mention the drag it induces. But until someone learns how to build a rear that doesn't lift, it will be with us in one form or another.

As speeds continued to go up, some front-end lift was encountered again, and once again. there appeared appendages on the front end this time very small tabs at the lower edge, one on each side. These were seen first on the car Sharp drove at Riverside in May 1965. At Mosport the next month there were much larger versions of the same front tabs on bothcars entered-now looking very much like pieces. of a cowcatcher on an old steam locomotive. These vanes trim tabs whatever have remained the same since then.

The subject of aerodynamics in these 150-mph-plus racing cars is still one of question marks and guesses: Hall thinks very few people know much about automobile aerodynamics, especially in the range of 150-200 mph, though many have strong opinions because, as he says, "They held their hand out the window of the family car once." Wind tunnel tests furnish some information, but unfortunately don't accurately reproduce what is happening under the car. In a tunnel there's no relative speed between the car underside and the road surface and the wheels are usually not turning in an aerodynamic test. Hall proceeds on what data he can get by running tests at his track, and no doubt he has access to some kind of wind tunnel though he is not specific about this.

There have been revisions to the rear section, too, actually too many to delineate in detail. The latest one, as seen on the 2C, eliminates the large ducts high on the flanks which were there for direct engine-compartment cooling; it was found that this cooling wasn't needed after all and the ducts were adding drag.

Driver-controlled Spoiler

The most discussed feature of the new rear end is the movable spoiler (also adapted to car No.3, which still has an older-style rear end). The movable spoiler was a natural for the Chaparral, because a spoiler's drag makes it desirable to get it out of the airstream when its downward force isn't needed; the relatively-free left foot was available to operate another pedal, so why not? An extra master cylinder, a small pedal off to the left and a hydraulic piston comprise the actuating mechanism for the spoiler. In cross section, the spoiler is somewhat like an airfoil. When the spoiler is in the "down" position (parallel to the body of the car), the frontal area is appreciably reduced. There also appears to be some "trim" built in to contribute downward force to the rear end without adding the amount of drag that results from, a conventional fixed spoiler. Prom watching the spoiler in action at Riverside and Las Vegas, it would appear that the spoiler is moved "down" (horizontal) on high speed sections of the circuit where it could be expected that top speed could be increased by the reduced frontal area and then moved "up" (nearly vertical) before applying the brakes. In the "up" position, the spoiler increases the amount of downward force on the rear of the car, in effect pushing the back end down so that the brakes, when applied, are more effective than they would be otherwise. Much of the time the spoiler is carried in the normal spoiler (vertical) position.

Suspension & Wheels.

Suspension development has been and is, continuous. The major part of it, however, took place in the first year of the Chaparral 2. Increased speeds have meant increased loads, and many pieces have been either completely redesigned or beefed up from their original Lotus form. For instance, the present front steering knuckle is a complete redesign job, weighs more than the original one, and is 4 times as strong. We're not saying that the geometry hasn't been refined, either-the cars are currently cornering at 1.2 G.

Another example of design refinement is the redesign of the hubs. The original ones were installed by putting a bolt through the flange and were locked in place by friction. Removing them a couple of times wore,them out. Now they are a sized fit, with a ring on back and a notch on the head of the stud-locked in place, they can't turn, and hence don't depend on a friction surface that will be done in after a couple of R&Rs.

The wheels have been another major development program, which grew out of the brake program. Early in the car's career brake pads were wearing too fast and seals were cooking. There was no problem with the discs themselves, but tests showed that under racing conditions, temperatures of 1100° F at the discs, 900° pads .and 500° fluid were being reached. The seal material was only good for 210°, so something had to be done. New seal material (which has since become the standard Girling seal material) improved the heat tolerance of the seals, but not enough to solve the problem.

Cooper wheels were tried next. These had more open area than the ones being used and resulted in some reduction in both seal and pad temperatures. This indicated that radiation played an important part in heat transfer frem the brakes. An ingenious solution came soon after: the Chaparral wheels, which have a spoke-like web structure and which add a full 1.5-in. extra diameter to the innerwheel paththrough which heat is radiated. from the brakes (photo on p. 80). The bead depression or drop center,-necessary in ordinary wheels to get the bead over the rim flanges, was neatly eliminated by 'making the outer: rim flange detachable from the main wheel body. The absence of thecdepression provided the extra inch and a half on the inside diameter. A further advantage of these wheels is that the same wheel body is used for both front and rear, as only the outer rim flange has, to be changed to furnish a wider rim at the rear.

Engine Durability

Engine development is another story that has consisted more of making it reliable than.making it develop more power. Right now the Chaparrals are having less Chevrolet engine trouble than anybody else's cars and, according to Sharp and Hall, it's because their Chevrolet engine is more nearly stock than any of the others.

They're using aluminum blocks and heads, the resuit of a happy circumstance in which Alcoa salesman (at that time) Roger Penske talked Chevrolet Division into loaning him the tooling originally intended for Gran Sport Corvette use. By doing so they save about 110 lb over the cast-iron engine; but the aluminum block also limits them to the stock bore. Hence they're running 327 cu. in.

Since the inception of the automatic transmission, it has been found wise to back off a little on engine power output for the sake of getting good torque over a wide range of engine speed. Contrary to some reports, the (transmission does not allow nearly constant engine speed to be maintained over a large band of road speeds, and because it has only one stepped gear reduction, there isn'1 the chance to keep the engine in a narrow speed band by changing gears often.

A surprising number of pieces from the friendly Chevrolet dealer's parts bin are used in the engine. (By the way, Hall and Sharp now own, the friendly Midland Chevrolet dealership.) The pistons are stock but for a stress-relieving hole drilled at each end of the slot in the oil-ring groove to stop cracks. Also stock are the crankshaft, main rod bearings, and rods-though of course all components are sized, balanced and fitted with extreme care. Present average output of the Chaparral engines is about 415 bhp at 6800 rpm, 380 Ib-ft torque at 5200 rpm. In the works for 1966 racing is a change to 58-mm Weber carburetors (presently -they are 48 mm) and the concomitant exhaust tuning.

The 2C Exercise

As is usually the case with durability development, the Chaparral gradually put on weight. It did get faster in the process, as well as more comfortable, predictable and, as Hall puts it, "Just nicer to drive." Constantly searching for ways to pare the weight "back down, Hall and Sharp, decided upon trying an aluminum chassis for the 2G. Of the same basic design as the plastic one used for the three 2s, the aluminum frame saves about 70 lb directly and 100 lb in vehicle weight. However, neither Hall nor Sharp are completely sold on aluminum yet. Balanced against the weight saving is the fact that an accident almost inevitably will destroy the whole aluminum frame, whereas the plastic one can be repaired by bonding in new pieces. Hall also admitted some reservations about the safety for the driver with the aluminum frame, though he, like most of us, doesn't profess to know much about what's safe and what isn't in an accident.

This, then, is a brief summary of development to date. Central to the development story is the fact that the car has remained adequately fast for two years instead of the usual one. No really drastic single changes have been made, but the evolutionary process has been such that today's Chaparral 2C doesn't look much like that original 2.

Driving Strategy

Another aspect of the Chaparral Cars approach is their handling of drivers. Hall, as we said, is generally considered to be the star driver, and Sharp the backup man. Sharp usually drives at a respectable distance behind Hall by choice, we would say, because he's a highly cautious person when it comes to driving. At the Stardust GP recently Sharp could be seen to let the gap between himself and Hall increase in the last few laps, when things looked safe enough to do It.

Other drivers currently on the Chaparral team are Ronny Hissom, another oil operator who also owns a Ford dealership (that's right, Ford) in Silverton, Texas; and Bruce Jennings, better known as a Porsche driver, from Towson, Md. Hall and Sharp say that they've had many requests for rides from much better known drivers, but they like the drivers they have. "They're not trying to prove anything to" anybody," says Sharp of his drivers. "They're not going to go out and break the car trying to get glory for themselves; instead, if we tell them to try and run a good third, that's exactly what they do. And they're good drivers in their own right."

The Results

The competition record of the Chaparral 2 speaks eloquently for the value of the Hall-Sharp approach. 1963, the first year out, was only a teething period and didn't make history 1964 and 1965 were another story, however: in 1964 it went like this of 24 starts in 15 races, there were 8 firsts, 5 seconds, 2 thirds and 8 retirements. In 1965 the record has been downright brilliant: of 36 starts in 20 races, there were 17 firsts, 7 seconds, 2 thirds, 5 miscellaneous finishes out of the money and only 5 retirements. A phenomenal record. No other modern day sports car even comes close.

And the peak, though it may have been reached, doesn't seem to be passed. Right now there are faster cars-several of them but none with the same combination of speed and reliability.

The Future

When the 2C first appeared at Kent, Washinston, in September 1965, many were disappointed, for rumors had been hot and heavy that the new car would be revolutionary. The fact is that the 2C really isn't the "new car." It's another refinement of the 2, and by the time of its advent the builders had made enough changes in the series to set it off with the "c" suffix.

The center body section of the 2C is a little lower than the 2 but the fenders are of the same height; the chassis, but not the body, conforms to PIA specifications. Overall body width has been cut 6 in. and front and rear suspension geometry has been modified slightly for more anti-dive, lift and squat, A total of 100 lb has been saved by use of the aluminum chassis, and all the latest body revisions are incorporated. But it is not nearly as significant as will be the Chaparral 3 when it appears though we make no pretense of knowing when that will be.

Any discussion of the future must include some mention of such things as "What we don't know now," and "What we're going to have to get into," when you're talking with a man like Hall. Specifically, he had this to say: ". . . We haven't got into dynamics-transient behavior. What happens as a car rolls into its lean position-as the car settles into brake dive. Since we haven't studied these things yet, we've simply minimized them (roll and dive). Time lag prevents the driver from getting the right braking force set up at first, for instance: he might lock the front wheels before the full weight transfer had taken place." Not exactly what you'd call seat-of-the-pants planning.

The most exciting news about the future that can be told now is Chaparral's announced intention to build cars for the FIA GT Prototype class for the coming year. A chassis is being built right now and, interestingly enough, it's plasticsomewhat lighter than present plastic ones.

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