1989 Ford Probe
High-Performance For The Masses
By Myron D. Stokes

Ford's all new turbocharged Probe has risen from a long awaited rumor to solid reality. With this new performance offering, Ford has its sights on the serious performance enthusiasts and the masses, as well as taking charge over the import grip.

The intent behind the Probe was to develop a successor to the legendary Mustang pony car which would utilize the very latest in engine performance and suspension technology. At the time of program implementation in 1982, this translated into turbocharging and intercooling of a four-cylinder powerplant to provide the necessary muscle, front wheel drive, and perhaps cockpit adjustable shock damping.

We would be remiss at this point if we didn't discuss the introduction of the SVO Mustang (See Turbo Sept, '86) which incorporated all of the technology - save for active suspension-proposed for the Probe. While the car didn't do as well as projected in sales, Ford was nonetheless accorded some unique insights into Mustang buyer psychology. Interestingly, during the time which Ford had decided on a high-tech replacement for the Mustang in 1982, the current model year car - with an honest-to-goodness high-output 302 V-8 - was being hailed as the harbinger of a new era of performance.

The powers that be at Ford evidently didn't listen closely to what Mustang mavens were saying and as indicated by a resurgence to sales. A few short years later, however, when word leaked out to owners and clubs that their beloved Mustang was to be replaced by a front drive four cylinder something, and worse, a hybrid AmeriJapanese something, it was too much. Letters of vehement protest poured in to Dearborn, Michigan executive offices. Some even offered that only Coca-Cola had committed a graver marketing sin.

To its credit, Ford listened and decided that performance buyers would permit the existence of both the traditional Mustang (recently given a stay of execution until 1993) with rear drive and V-8 power arid the new sibling. They decided to call their version of this cooperative endeavor Probe (after the experimental GTP car) while Mazda christened theirs MX-6. Both cats would be built at Mazda's brand-new Flat Rock, Michigan plant, with the Probe gradually phased into the production line. This would eliminate "block" production, which. involves building alternately, for example, 25 Probes and then 25 MX-6's throughout the run.

While acceleration qualities for the Probe and MX-6 GT are pretty much on par, there is a distinct personality divergence in terms of handling characteristics. The Probe's automatic-adjusting four-wheel independent suspension arrangement, with higher spring rates and other tweaks, provides the car with a tauter, more responsive feel; one that asks you to explore its limits with confidence. Helping to inspire that confidence is speed sensitive power-assisted rack-and-pinion steering with disc brakes on each corner. Considering the car's 130 plus mph terminal velocity, anti-lock is highly recommended. Finally, Probe's contact with the road surface is maintained by Goodyear P195/60VR15 Eagle VR 60 performance tires mounted on cast aluminum 15 x 6 wheels.

Aesthetically speaking, the Probe GT will get the nod in the macho appearance ratings department, with the MX-6 GT garnering a very close second. The difference in looks are the result of the design teams for Ford and Mazda having separate studios at the latter's headquarters in Hiroshima, Japan. Bear in mind that the original program outline relegated the Find team to an advisory role only.

The Ford design incorporates more glass area for enhanced visibility, somewhat better aerodynamics and retractable headlamps - clearly setting it apart from Mazda's interpretation. Make no mistake, however, both company's will sell a ton of these high-tech gems even in the face of such formidable competition as Toyota's Celica GT's and Nissan's 200 SX. And considering the blistering performance capabilities of these modern-day twins, we see them possibly taking on cars in the league of the 300ZX and Supra normally aspirated form.

For one, the price is definitely right for a base Probe GT at $13,593 and a few shekels under $16,000 for all the available toys like a trip computer, compact disc player and anti-lock braking. On close inspection of the car's eye-popping exterior and an interior that invites one's continued presence, you'll conclude that the Ford design guys didn't burn the midnight oil in Hiroshima for nothing. "We expect to sell on a on-going basis 150,000 Probes per year, with the GT making up 25% of that production;" said Al Kleinke, Ford Market Representation Manager during the February kick-off of a 25 city dealer introduction in New Orleans. "The Probe will be recognized as another step in continued styling superiority, and another step forward for Ford. It is an excellent value for the money."

Kleinke also stated that Probe, as well as the Taurus, would be shipped to Japan with distribution and sale through the dealer Autorama network. "We expect to sell thousands of units, instead of the traditional few hundred, if that," he said. Very much in evidence here is a high level of confidence in the quality of build for these cars.

On these shores, we predicted with fair accuracy that Probe GT would be an outstanding success when it went on sale the 12th of May.

Following the "complete package" philosophy first used to advantage in the 1983 Thunderbird Turbo Coupe, Probe GT, especially when fully optioned out, offers all the necessary accouterments- for some serious cruisin'. The Mazda designed 3-valve (2 intake, one exhaust) turbo engine pulls strongly right up to redline. A 5-speed manual overdrive transaxle is the only transmission available on GT and seems quite up to task in precision channeling the bulk of 145 romping horses to the drive wheels the average 0-60 mph time of 7.5 sec claimed by Ford is quite true.

The Probe GT's engine utilizes a computer controlled wastegate to permit overboost as long as conditions are favorable. Normal boost pressure is set at 7.5 psi occurring between 2000 and 2500 rpm. Under "favorable" operating circumstances such as full throttle, cool ambient air and premium octane fuel, boost is allowed to build to 9.2 psi at 3000 rpm. Notice that while this turbo boost control system is similar to Chrysler's, no timing arrangement whereby boost can only occur within a preprogrammed time/frame is used.

With no time limit and highly discretionary ignition control microprocessing that is not unlike Peugot's cartographic ignition system (See Turbo, March '88) the power levels continuously available go a bit beyond officially stated output. The 145 hp is obviously the "steady state" net rating derived via standard SAE power measurement procedures. We feel that the horsepower is more like 170/175. And torque? We were advised by Ford engineering personnel that the torque curve remains almost flat over a 1500 rpm range. Curve graphs show maximum torque beginning at about 2500 rpm with 188-190 lbs/ft; peaking to 190 @ 3500, and decreasing slightly to 180 @ 4000 rpm.

The heart of Probe GT's exciting performance is, of course, its turbocharger. Built for Mazda by IHI, the unit is 52.5mm in diameter; has a housing constructed of NiResist, a high temperature, heat-proof cast iron; and a maximum rotational speed of 180,000 rpm. The Turbo's low inertia design permits rapid "spool-up" and results in the developing of usable boost at low rpms. The engines ability to produce near peak torque at 2500 rpm confirms this.

Contributing to the quick low-end response is 3-valves per cylinder within the engine head. These valves - two intake and one exhaust - are actuated by a single overhead camshaft through rocker arms enclosing hydraulic lash adjusters. They are inclined at a 38 degrees vee-angle within a shallow multispherical combustion chamber. The spark plugs are positioned close to the center of the chamber dome so as to insure good flame propagation.

Probe GT's prodigious amounts of power and torque flows through a 5-speed manual transaxle - with strengthened gear box and clutch to the drive wheels. Final drive ratio is 4.10:1.

The front suspension is comprised of nitrogen gas-charged Macpherson-type shock/struts, lower control A-arms and strut-mounted coil springs. Bringing up the rear are gas-charged four-bar link shock struts with single trailing arms and upper strut-mounted coil springs. Body roll is kept in check through the use of front/rear stabilizer bars.

Of interest is the fact that while the suspension is a Mazda design, its turning was carried out by Ford engineers. Again, this was to insure a distinction in Probe GT's handling characteristics as opposed to MX-6 GT.

Augmenting Probe GT's ride quality is computer-controlled variable shock damping. Similar in function to that of Thunderbird Turbo Coupe, this suspension feature utilizes sensors which monitor vehicle speed, acceleration/deceleration forces, lateral movement and steering wheel angle. The data is fed into a central microprocessing unit which analyzes and then issues the appropriate firmness setting to shunt motor actuators atop each shock-strut. The clearances made for the shock towers are discernible from the exterior by way of those muscular-looking bulges on either side of the hood.

There are operational differences, however. Like the Turbo Coupe, Probe GT has optional shock damping programs. Turbo Coupe has two modes: "Auto" and "Firm." The "Soft" on the Probe setting provides for the most gentle shock damping - thus promoting a smooth and supple ride. In "Normal-Auto" the shocks remain at a soft setting that will instantaneously increase to "Firm" the moment any of the preset automatic shock adjusting parameters are met. In the "Sport-Auto" program, "extra-firm" will result. In this mode, the damping progresses from a "medium" setting. Interestingly, when vehicle speed exceeds 50 mph in straight-ahead driving, only the front shock-struts are adjusted. Based on the latter operating condition, we must conclude that there are actually four shock damping programs.

In other areas of Probe GT technology, anti-lock braking is optionally available. But unlike Turbo Coupe, it is not integrated operationally with the Automatic Adjusting Suspension to negate, for example, the nosedive phenomenon during hard braking (See Turbo, Nov. '86). But in due consideration of Probe's lighter vehicular mass by 2631bs., the inclusion of this feature is perhaps not as critical.

Lastly, Probe GT's directional accuracy is assured through a velocity-based, variable assist power rack-and-pinion steering system. Acting on signals from sensors programmed to respond to changes in steering wheel angle and/or vehicle speed, power assist is pronounced at low speeds - as when parking - and steadily reduced as speed increases.

All of the above-mentioned technologies work in concert to form an automobile with the agility of a feline and a quickness that never fails to excite. Simply said, Ford has hit another home run.

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