What the 1978 Jaguar XJ-S Group 44 Was

The 1978 Jaguar XJ-S Group 44 Trans-Am was a race car built by Group 44 Inc., an American racing team, specifically to compete in the IMSA Trans-Am series. It took the production Jaguar XJ-S coupe — a luxury grand tourer that had just debuted in 1975 — and stripped it down to a racing machine with a modified engine, racing suspension, and aerodynamic bodywork. Group 44, led by driver and team owner Bob Tullius, was known for taking production cars and turning them into competitive race cars, and the XJ-S represented their most ambitious project at that time.

This particular car was significant because it marked Jaguar's return to American motorsports after a long absence. The XJ-S had a V12 engine that Group 44 tuned for racing, and the team made extensive modifications to the chassis, brakes, and cooling systems to handle the demands of Trans-Am racing. The car competed in the 1978 and 1979 seasons, driven primarily by Bob Tullius himself.

Key Takeaways

  • Group 44 Inc. converted the production Jaguar XJ-S into a Trans-Am race car by modifying the V12 engine, suspension, and body to meet racing specifications.
  • Bob Tullius, the team owner and primary driver, piloted the car in IMSA Trans-Am competition during 1978 and 1979.
  • The car was notable as Jaguar's return to American racing and demonstrated that a luxury grand tourer could be competitive in a racing series dominated by purpose-built machines.
  • The XJ-S Group 44 competed against purpose-built race cars and American muscle cars, making it an underdog entry in the series.

The Group 44 Team and Bob Tullius

Group 44 Inc. was founded by Bob Tullius in the 1960s and became known for taking production sports cars and racing them successfully in SCCA (Sports Car Club of America) events and professional series. Tullius was both the team owner and a skilled driver who understood how to extract performance from road cars. Before the XJ-S project, Group 44 had success racing Jaguar XKE models and other British sports cars.

Bob Tullius was instrumental in the XJ-S project because he believed the car had potential despite its luxury-car origins. He worked closely with Jaguar engineers and his own team to develop the race version. Tullius drove the car in most of its Trans-Am appearances and was instrumental in proving that the XJ-S could hold its own against purpose-built competitors.

Engine and Mechanical Modifications

The production XJ-S came with a 5.3-liter V12 engine producing around 285 horsepower. For racing, Group 44 modified this engine to increase power output, though exact specifications varied depending on the season and specific race regulations. The team worked within Trans-Am rules, which limited modifications but still allowed significant tuning of the engine internals, fuel system, and ignition.

Beyond the engine, Group 44 upgraded the cooling system substantially because the V12 generated considerable heat during racing. The team also modified the transmission, suspension geometry, and braking system to handle the stresses of road racing. The modifications transformed the XJ-S from a comfortable grand tourer into a machine capable of competing on tracks like Road Atlanta, Watkins Glen, and Riverside International Raceway.

Body and Aerodynamic Changes

The race version of the XJ-S retained the basic shape of the production car but received significant aerodynamic modifications. Group 44 added a front air dam, modified the hood with vents for engine cooling, and fitted a rear wing to generate downforce. These changes were necessary because the XJ-S's original body was designed for highway driving, not high-speed cornering and braking.

The team also widened the fenders to accommodate wider racing tires and adjusted the overall stance of the car. The interior was stripped of luxury appointments — sound deadening, carpeting, and trim were removed to reduce weight. A racing harness, roll cage, and fire suppression system were installed to meet safety regulations. The result was a car that looked like an XJ-S from a distance but was fundamentally a race car underneath.

Trans-Am Series Competition and Results

The XJ-S Group 44 competed in the IMSA Trans-Am series, which was one of the premier racing series in North America during the late 1970s. The series featured both purpose-built race cars and modified production cars, with strict rules governing engine displacement, modifications, and weight. The XJ-S faced competition from Chevrolet Camaros, Pontiac Firebirds, Ford Mustangs, and other American muscle cars, as well as Porsche 911s and other European sports cars.

The car achieved moderate success during its racing career. While it did not dominate the series, it proved that a luxury grand tourer could be competitive and earned respect from competitors and racing fans. The XJ-S Group 44 scored points in several races and demonstrated that Jaguar could return to American motorsports with a viable competitor. The project lasted through the 1978 and 1979 seasons, after which Group 44 moved on to other racing programs.

Historical Significance and Legacy

The 1978 Jaguar XJ-S Group 44 Trans-Am car holds significance in both Jaguar and American racing history. For Jaguar, it represented a return to motorsports in the United States after years of focusing on road cars. The project showed that the XJ-S, despite being a luxury car, had the fundamental engineering to support racing modifications. For Group 44, it was one of the team's most visible projects and demonstrated their ability to work with a major manufacturer on a professional racing program.

The car also represented a particular moment in racing history when the line between production cars and race cars was still blurred. Modern racing series typically use purpose-built chassis, but in the 1970s, modifying production cars was still a viable and respected approach. The XJ-S Group 44 was part of that tradition, showing that creativity and engineering skill could make a luxury car competitive against purpose-built machines.

Where the Car Is Today

The original 1978 Jaguar XJ-S Group 44 Trans-Am car survives and has been preserved by collectors and enthusiasts. The car has appeared at historic racing events and car shows, where it is recognized as an important piece of racing history. Several organizations dedicated to historic motorsports have documented the car's history and specifications.

The car represents a unique chapter in Jaguar's racing program and remains one of the most recognizable XJ-S variants ever built. Its survival and continued visibility in the collector car and historic racing communities may support that the story of Group 44's ambitious project continues to be told to new generations of automotive enthusiasts.

Frequently Asked Questions

Did the Group 44 XJ-S win any Trans-Am races?

The car competed in Trans-Am but did not achieve outright race victories. It scored points in several races and proved competitive, but the series was dominated by purpose-built race cars and well-funded American manufacturers. The significance of the project lay in demonstrating that the XJ-S could compete at a professional level, not in accumulating wins.

How much horsepower did the modified V12 engine produce?

Exact horsepower figures varied depending on the season and specific race regulations, but the engine was tuned to produce significantly more power than the production version's 285 horsepower. Group 44 worked within Trans-Am rules, which limited modifications but still allowed substantial engine tuning. Specific output numbers were not always publicly documented.

Why did Group 44 choose the XJ-S for Trans-Am racing?

Bob Tullius and Group 44 believed the XJ-S had potential as a race car despite its luxury origins. The V12 engine was powerful, and the car's solid engineering provided a foundation for modifications. The project also represented an opportunity to work with Jaguar on a high-profile racing program and to demonstrate Group 44's capabilities to a major manufacturer.

How long did the XJ-S compete in Trans-Am?

The car competed during the 1978 and 1979 seasons. After that period, Group 44 moved on to other racing programs. The two-year campaign was significant enough to establish the car's place in racing history, even though it was not a long-term program.

Can you still see the Group 44 XJ-S at racing events?

Yes, the original car has appeared at historic racing events and car shows where it is recognized as an important piece of automotive history. Historic motorsports organizations and collector car events occasionally feature the car, making it possible for enthusiasts to see it in person.