30-yr anniversary of the debut of the Mustang SVO at Nelson Ledges
30 years ago, June 18-20 1982, Ford debuted the Mustang SVO to the world in the form of two engineering prototypes competing in a 24-hour endurance race: the Quaker State Oil Longest Day of Nelson. This SCCA-sanctioned race, held at the well-known (and very humble) club race track Nelson Ledges in Ohio, isn’t with us anymore but was well-known and beloved in its time. The event offered classes for what at the time was known as Showroom Stock cars, as well as future production prototypes, to race.
The SCCA Showroom Stock class in those days was just that: cars that were literally straight from the showroom, with only safety equipment added. Race tires were not available in those days, so whatever street tire came in the stock size would have to be used. Ford Pintos were very popular then because of their crisp handling and easy availability of replacement parts. We personally knew one racer who leased his from a local dealer and had several crashes over the years.
The Prototype class was something new to the SCCA, and it was controversial both inside the SCCA as well as outside. The intent was to generate excitement by allowing manufacturers to bring a prototype of a car that would be built within the next two years. It wasn’t intended for high-end or exotica, but for future versions of cars already racing in Showroom Stock. The Corvette wasn’t allowed into the event until 1985, and even then only under pressure from GM, but the Mustang was the perfect fit since it has already been racing in Showroom Stock since 1979. Racing would indeed improve the breed.
Ford brought two prototypes to the event with the idea of fast-tracking their development under the stress of racing, as well as to show the public the direction that the Mustang was taking. And to ensure that good publicity was spread far and wide, Ford arranged for Car and Driver and Road & Track to each have their own identical car. The magazines selected their drivers from amongst their own staff, which resulted in a mixed bag of skillsets. Road & Track had Innes Ireland, for example, and there was no question of the skill there. Each magazine also brought nearly their entire staff to crew their pits, cook for everyone, and cheer on their (hopefully) winning team.
And we were there ourselves, working as an SCCA-licensed Pit Marshall. That meant that we were working in the pits, right in front of the Mustang SVOs, and saw everything. We also got to meet our favorite writers from both magazines. What an incredible weekend!
And, since we were driving Mustangs in those days in track events, we got an inside view in the direction that our favorite car would be taking. And a much-needed direction it was. Going to a two-day track weekend in a Mustang of that age meant that all the inherent engineering weaknesses of the car would conspire to do their best to hurt your weekend, if not to hurt you personally. Front disc brakes were tiny then, and of course the rears were drums. The 190 section width Michelin TRZ tires were lousy, without any replacement alternatives. The Mustang used 4-lug brakes, embarrassingly. Bearings were very weak. At a faster track, such as Watkins Glen, that meant that you had to go to the track on new brake calipers, bearings, and rotors up front. And you would have to change them ALL Saturday night because they would ALL be worn out. So before getting the nice meal you earned from driving hard and fast all day, you had to perform a dirty greasy brake job. And they would wear out again on Sunday, but you had to take it easy so that you had enough brakes to drive home with. Wonderful. And in the heat of the summer your radiator probably garked its fluid all over your parking area – be it on the grass at Nelson or in the garages at the Glen.
Clearly something needed to change. And that something was parked right in front of us at Nelson Ledges. The SVO engineers addressed every single problem the Mustang suffered from – particularly the lousy brakes, front end geometry, shocks and spring rates, wheels and tires, cooling, transmission, aerodynamics, seating, and more. In other words, Ford was going to bring to market what we call “a complete car” – a car that you didn’t have to modify just to get it thru a track weekend. For us, and for all Ford driving enthusiasts, the answer to our hopes was sitting right in front of us. I was tagged to work alternating four-hour shifts, and by choice right in front of the shared pits of both these cars. Ford brought the SVO engineers to the race to take care of the cars and I had the chance to talk to them at length. I spent the rest of my time walking around the track observing the cars on the track. Like most of the fans that weekend, I didn’t get any sleep. No problem.
Lets look at the cars!
This picture illustrates the prototype nature of the 1982 SVO race car. Several things of note in this picture:
- Jack Roush built the engines for both cars, along with backup spares.
- The turbo mounting and intake manifold were nearly at the production level. However, the throttle body was not.
- Note the intercooler tubing. The intercooler itself was mounted integrally with the radiator – and neither one was sufficient. This design created an enormous turbo lag, and also wouldn’t survive in a crash. The intercooler would have to be moved before production.
- Note the two hoses leading down to the turbo from the firewall – these were intended for cooling and probably weren’t very effective – but they did indicate a problem that Ford was aware of
- Battery location. The under-hood layout was beginning to evolve in the FOX Mustangs. The battery was moved to the right side, where it remains to this day, although in this iteration it was sideways instead of lengthwise.
- The remote oil filter. Since the 2.3 engine was derived from an earlier engine (that certainly was never envisioned for a Fox Mustang), Ford was stuck with the stock location of the oil filter.
- The power steering pump reservoir fill extension. This was a trick Ford learned from the earlier efforts of its engineers in showroom stock racing. The fluid in the power steering pumps would heat up so much that after “extended operation” it would boil over into the engine compartment. While Ford later added a simple cooling loop, this problem was never entirely fixed until the SN-95 redesign.
Close-ups of the intercooler routing. Due to crash standards, this arrangement could never be used in production. Yet given the basic layout of the engine compartment and the length of the front end, there were very few alternatives. The production solution was an intercooler mounted directly over the turbo, fed by a hood scoop (which at higher speeds, vented air in the wrong direction).
A view from the drivers side. Notes:
- the elbow going downward into the intercooler. It was cobbled together here (note the tape), and certainly could never survive even a mild crash. For production, it would be important to design a level of survivability: many customers would attempt to drive the car away from a crash for repair and a broken intake line would leave the engine open to destruction.
- the radiator was approximately half the width of the engine compartment. This was also a compromise to allow the intercooler to face directly in the airflow. This was also never intended for production.
- the large master cylinder. Because of the new 4-wheel disc brake system, a new master cylinder was needed to supply the proper pressure to all 4 disc brakes.
- the extension to the power steering reservoir fill tube. Ford knew even then that boiling power steering fluid was a major issue. This was a trick to increase the size of the reservoir so that when the fluid inevitably boiled, it wouldn’t go over the top. This is a fix many of us used on our own cars, although Ford never made a production change.
This is another view from that side, showing the prototype intake manifold. A considerable amount of work had gone into it’s design, which was so efficient it outlasted the use of the 2.3 liter engine in the Mustang. Note the tiny radiator – it would prove to be a negative factor in the survivability of this car in the race.
At this point, the body of the car was entirely stock. While a fully-dressed prototype would certainly have existed inside the Ford design studio, it certainly couldn’t be shown to the public this early before production.
The prototypes were built from base 4-cylinder cars, and featured the lowest level of trim on the inside. They did use the 79-82 style “Cobra/GT” style nose with a hood scoop for intake clearance.
The prototypes used sand-cast 16×7″ aluminum wheels with European Goodyear Eagles. These wheels were very early prototypes and didn’t have cooling slots cast in them (another item which would prove to be a factor in the race). This casting process wouldn’t be used in production but according to my talks with the Ford engineers the wheels were believed to be sufficient in strength for the event. You’ll notice they seem to have just a little bulge outwards in their design.
One of the more promising features in the car was the 4-wheel 5-lug disc brakes. The prototypes used an off-the-shelf Lincoln Versailles system, including it’s 9″ axle and limited skip differential. That wasn’t intended for production, either, but it was all that was available at the time. This picture also shows the prototype fuel injection lines and filter. Note the traction bars that were used in the ’84 cars.
Both cars faired well in the event, although they both required an engine change in the middle of the night. The prototypes used stock engine blocks -the stronger block and internals intended for the SVO weren’t yet available. Both also suffered from front brake and wheel bearing problems, although not to as severe a degree as the GTs did in the same conditions.
The prototypes showed some extraordinary speed and handling attributes, in marked contrast to the V-8 Mustangs. Mustang enthusiasts who attended were extremely enthusiastic about the possibility of buying such a car!
Here a prototype is passing one of the Pintos entered in the event. Imagine the difference in evolution between the two cars shown in this picture – the Mustang that this new “Fox” generation had replaced was itself based on the Pinto!
Besides a couple of teething problems with the prototype brakes and cooling, disaster hit both cars in the middle of the 24-hour period when both blew their Jack Roush-built engines. And due to lengthy engine changes, both cars finished dead last in the event. The Car and Driver car completed 667 laps, and the Road & Track car completed 661. The winning car, Porsche 944, finished 960 laps.
But the concept was proven, the point was made, and the prototype SVOs ran extremely well. The Mustang SVO itself was intended to be offered as a mid-year addition to the 1983 lineup. We don’t know the full story behind the car, but it was delayed until 1984. Perhaps due to the economy, perhaps due to availability of a stronger engine block and production timing. And what we saw at Nelson Ledges wasn’t the final prototypes of the production car, as we clearly saw the intercooler design was temporary and the entire rear axle and brakes weren’t the actual prototype parts at all.
So as a potential Mustang SVO buyer, we had to wait an unknown amount of time for the car to reach production. Little did we know it would be two full years. But in the meantime, Ford brought a nearly complete prototype to Nelson Ledges for the 1983 event, and this time its own drivers would drive the car. And the competition would be back too, Chevrolet with a full-tile Z88 Camaro, and Porsche with a prototype 944 Turbo (caught cheating and worse). We were also there, and even more excited as the SVO cleaned up the track, only to be purposefully bumped off the track by the cowardly Porsche team. Read the full two-year story here: http://www.drivingenthusiast.net/sec-ford/special-report-svo/.