It’s easily the best thing to come out of Dearborn since the 1932 V-8 Model B roadster. But for all Ford’s talk of Total Performance, it’s still clear that the Mustang has been designed and built to a price. The necessity of meeting cost goals meant that it had to share a maximum number of components with other models in the Ford line. Out of this situation sprang the advantage of an extremely wide availability of options for the Mustang, selected from the Falcon, Fairlane and Galaxie series. Briefly, it gives the customer a choice of four engines, three clutches, seven transmissions, two driveshafts, four brake systems, four wheel types and three wheel sizes, three suspension systems, and three steering systems. This seems slightly overwhelming until one remembers that only certain combinations are authorized, for either technical or commercial reasons. But it’s still very impressive and approaches the Tempest’s profusion of power team options. In two departments Ford even has the lead on Pontiac. Disc brakes are optional on the Mustang, and an independent rear end will be homologated and made available in small series for racing purposes.
Lee Anthony Iacocca, vice president and general manager of Ford Division, sees the Mustang first of all as a family car, which meant that it had to have four seats, with better rear seat accommodation than is offered in the “two-plus-two” category. It’s also aimed at a not-clearly-defined market consisting of customers looking for a not-clearly-defined combination of luxury and status. In addition to all this, the Mustang is intended as a sports car (or sporty car).
The project was initiated in 1961 following the increased acceptance of sports car features in family cars, such as stick shifts and bucket seats, and after strong indications of an undiminished public demand for the pre-1958 two-seater Thunderbird. The basic specification of the Mustang was laid down after extensive market research, just as in the case of the Edsel some years ago, but in contrast with the Edsel the Mustang is hitting the showrooms at the right time—while the GT (and pseudo-GT) craze is still in high gear. While the term Gran Turismo really sums up everything that Ford wanted this car to be, they are to be congratulated for not sticking those initials on the Mustang, in the manner of models which served only to render them meaningless, such as the defunct Studebaker Avanti and the popular Dodge Dart GT.
The Mustang design was entrusted to Jack Prendergast as executive engineer under the direction of Hans Matthias, chief engineer of the Ford Division. The Mustang was built up on a basic platform steel frame with galvanized structural members and torque boxes. The frame was designed to carry all the mechanical elements on the under-side and all the body components on top. Structural rigidity was assured by a strong propeller shaft tunnel stretching from the toeboard to the rear axle kick-up, plus cross-ribs and reinforcements. The platform is so stiff that the chassis can be driven without a body.
The body panels are welded to the platform, forming an integral all-steel structure of light weight (during the entire design stage, weight control was held to strict tolerances). The engine compartment is formed by full-depth side members welded to the front side rails at the bottom and to the cowl at the rear. Across the front, the box is completed by a one-piece stamping with a deep rectangular channel-section at the top. The front fenders are simply bolted on to this structure. The frame design is the same for both hard-tops and convertibles, but certain underbody members use heavier-gauge steel on convertibles to compensate for the absence of a roof.
Front suspension has been lifted directly from the Falcon, and consists of an upper wishbone, a single lower control arm with a stay extending to the front, an anti-roll bar, and a coil spring enclosing a telescopic shock absorber located on top of the upper wishbone. The top spring mounting is part of the engine compartment, and a rubber bump stop is mounted on a separate bracket attached to the frame side member.
As can be expected, the front suspension in its stock form is pretty flabby, but fortunately a “handling package” is available. It comprises such helpful items as heavy-duty coil springs, special shock absorbers, a larger-diameter anti-roll bar, 6.50 x 14 tires (instead of 6.50 x 13) on 5-1/2-inch wide rims, and a quicker steering box (with a ratio of 16 to one instead of 20 to one). Actually, the handling package becomes indispensable for anything but the most uninspired driving and ought to have been made standard in the first place. This is especially true of thesteering, as the “quick” ratio feels slow and the slow one is far and away too slow. The 16-to-one ratio will alarm no one by the rapidity of its response, but there will no doubt be a demand for an ultra-quick steering box, as the standard one demands 4-1/2 turns lock to lock, the quick steering takes 3-1/2, and the sports car driver will want about 2-1/2 (with the Mustang’s 38-ft turning circle).
Even if the “quick” steering is a little slow, the road feel is quite good, the power steering and its reduced feedback notwithstanding. Reactions to road unevenness in the wheel are very slight, and vibrations are not so much felt as hinted at. And if the response is lagging, the car is obedient enough once the front wheels have been pointed in the right direction.
Rear suspension is also based on the standard Falcon, with different forward spring mountings and beefed-up rubber bump stops. The leaf springs which were adequate with Falcon engine torque began to give trouble with axle tramp and spring wind-up during development with the 289-cu in Mustang V-8, so the springs were beefed up too. But both Matthias and Prendergast remain adamant that there’s no need for torque rods or any other aid to axle location. We are not perfectly in agreement with this, as leaf springs tend to be flexible in directions other than intended, and if they are to be made rigid enough for a high-performance car, it’s difficult to obtain spring rates low enough for acceptable ride comfort. Evidence of this difficulty shows up in the Mustang on the first gentle bumps. The front springs oscillate at a much higher frequency than the rear ones, giving the sort of ride one gets in a small boat hitting choppy waves head-on. The poop stays more or less put while the bow is bobbing in excitement. On the Mustang, the front and rear suspensions (in standard form) are absolutely not attuned to each other.
The good thing about leaf springs is that any change in their behavior is gradual, and consequently easily controlled and corrected by the driver. And from the manufacturer’s point of view, they make for a very inexpensive rear end. The shock absorbers are sharply angled, but the Ford press releases are incorrect in stat-ing that this type of mounting reduces side sway. It has no effect on sway whatsoever—its value lies in reducing lateral axle movements in relation to the chassis.
We did not get an opportunity to test the independent rear suspension. Its design resembles that of the Mustang I in having four transverse and semi-trailing links, with narrow-diameter inclined coil springs. This suspension is of very advanced design (by Roy Lunn) and modified only by Ford Division’s requirements for installation on the productionMustang. The wheels can be given adequate wheel travel and still have negative camber at all times, and spring rates can be set to suit a wide variety of driving conditions.
Roll center height with the independent rear suspension will probably be about 5 in, as on the Mustang I, as against 7.5 in on the rigid-axle model. Mustangs fitted with the independent rear end will have modified front suspension setups to raise the roll center from 1.7 in to 2.6 in.
Even in standard form the Mustang has less nose-dive than any other American-built Ford passenger car, but this is due more to the low center of gravity than to improvements in suspension design. The low center of gravity also contributes to reduce body roll, but on a 200-ft diameter circle, the car leans over just like a little Thunderbird. On high-speed curves, the roll is not objectionable.
We would not have expected the Mustang with its standard chassis to handle well. As a matter of fact, it is not bad. The car is so well balanced that it can be driven very hard and remain fairly stable and well in control. It has some initial understeer, seems perfectly neutral at normal speeds, and ultimately oversteers.
The basic engine for the Mustang is the 170-cu in Falcon six—a piece of machinery about as exciting as a dish of baby food. It develops 101 bhp at 4400 rpm and has a maximum torque of 156 lbs-ft at 2400 rpm, and can be combined with Ford’s three-speed manual transmission with non-synchro first gear, Ford’s four-speed manual all-synchro gearbox, or the new three-speed Cruise-O-Matic. The 200-cu in six is not available on the Mustang, neither is the 221-cu in V-8; the next step is the 260-cu in Fairlane engine, which develops 164bhp at 4400 rpm and has a maximum torque of 258 lbs-ft at 2200 rpm with a compression ratio of 8.8-to-one. Our test car had the 289-cu in version, with 9.0-to-one compression, four-barrel carburetor, and 210 horsepower.
What most enthusiasts will want is the high-performance version of the 289-cu in engine, which differs considerably from the standard 289. The Fairlane series is derived in its entirety from a lightweight cast iron V-8 designed by George F. Stirrat in 1958/ 59 and introduced in 221-cu in form in 1961. It weighed only 450 pounds complete, and had very compact dimensions: 8.93 in high, 16.36 in wide, and 20.84 in long.
Crankshaft design for this engine became the subject of a special study. The crank is made of precision-cast alloy iron and runs in five main bearings. About 70%of the total unbalanced couple is balanced by counter-weights on the crankpin webs, and the remaining 30% is balanced by two external counterweights—one mounted in front of the timing sprocket and the other integrally with the flywheel. In most previous passenger car applications of this engine, the fourth harmonic unbalance occurs beyond the normal speed range. But on the high-performance 289 the fourth harmonic comes within its 7000-rpm range, so the vibration damper developed for the Indianapolis engine, with enlarged rubber contact areas and tuned for higher crankshaft speeds, was adapted. The high-performance 289 also has the cross-bolted crankcase from the Indy engine, plus a number of special design features such as high-tensile strength connecting rods, copper-lead alloy bearing shells, chrome-plated valve stems, mechanical valve lifters, and a high-lift, high-overlap camshaft. The cylinder heads give a compression ratio of 10.5-to-one, and the air intake system consists of a low-restriction air cleaner, an opera-throat four-barrel carburetor, and direct manifold passages. The exhaust system boasts individual headers merging into twin tail pipes. Power output is an impressive 271 bhp at 6000 rpm with a maximum torque of 312 lbs-ft at 3400 rpm.Naturally this unit can be tuned still further for racing purposes by such patent medicines as Dr. Shelby’s Cobra Elixir (or imitations available from your local Performance Drugstore). Over 300 bhp may be reached without impairing engine reliability. Specific output of the hottest production model Mustang engine is 0.95 bhp per cu in, as against 0.73 for the standard 289-cubic-inch power unit.
Article published here.