OPEL GT VS. 240Z
The Opel GT returned for 1970 with a variety of minor refinements. The most notable was that factory air conditioning was now optional, reinforcing the perception that the GT was more of a stylish tourer than a sports car. The 1100SR engine remained nominally standard, but it was on its way out, having sold poorly even in Europe. It accounted for only about 10% of 1969 production and a tiny handful in 1970. The grand total was only 3,573 cars.
With the 1900S engine, the Opel GT acquitted itself well against rivals like the aging MGB, but the Opel had a formidable new rival in the Datsun 240Z, which arrived in the U.S. for the 1970 model year. The Z was slightly bigger than the Opel, just as well equipped, and far more powerful, with 151 hp (113 kW) from its 2,393 cc (146 cu. in.) six. It also had better handling than the GT, with fully independent suspension. In Europe, import duties tended to push the Datsun into a higher price class, but U.S. cars were aggressively priced, listing for only about $100 more than a GT with the 1.9-liter engine. Against the Z, the Opel’s only real tangible advantage was that it was possible to get one for something close to list price, while Datsun buyers faced waiting lists and substantial dealer markup.
GT production was down for 1970, but still topped 24,000 units, not bad for a small two-seater. European sales slumped badly, however, thanks, we suspect, to the popularity of the less pretty but more practical Capri. More than 85% of GT production now went to the U.S. Hoping for a little extra publicity, Buick became a sponsor of the popular TV spy spoof Get Smart. The fictional Maxwell Smart drove a Rallye Gold Opel GT throughout the show’s final season, which coincided with the 1970 model year.
Despite stock Opel GT’s middling performance, it had obvious potential. In 1970, Opel dealers in Italy persuaded Turin-based race builder Virgilio Conrero, famous for his Alfa Romeo racers, to prepare the GT for Group 4 competition.
The Conrero cars had five-speed ZF gearboxes, flared fenders, wider wheels, and an upgraded suspension with anti-roll bars and a Watt’s linkage replacing the Panhard rod. Their engines were bored out to 1,979 cc (121 cu. in.) and tuned for about 185 hp (138 kW). Conrero GTs competed in a variety of events from 1971 to 1973, including the Sestriere hill climb and the Monza, but their best showing was the 1971 Targa Florio, where a Conrero Squadra Corse GT driven by Salvatore Calascibetta and Paolo Monti won the under-2-liter GT class, taking ninth place overall. A few Conrero GTs were sold to private customers and Conrero offered tuning kits for interested buyers.
Around the same time Conrero started work on his GT, Henri Greder of the Greder Racing Team obtained two cars of his own through designer Franco Sbarro. The Greder cars were also expanded to about 2.0 liters (122 cu. in.) and fitted with cross-flow heads, giving around 200 hp (149 kW). When Sbarro and Greder were done with them, the cars themselves were Opel GTs in name only, with new tubular-steel chassis, fiberglass body panels, and fixed headlamps. One Greder GT, driven by Jean Ragnotti, achieved 10th place in the Lyon-Charbonnières Rally, but the cross-flow head proved problematic. Greder soon abandoned the GT in favor of newer Opels.
Another source of customized GTs was former BMW team manager Klaus Steinmetz, who offered an assortment of factory-approved tuning kits for Opel engines. Steinmetz offered a series kits for the 1,897 cc (116 cu. in.) CIH engine, ranging in output from 107 to 140 PS (79 to 103 kW), as well as a full-race version with around 200 PS (147 kW). The kits were sold in the U.K. through John Rhodes Tuning in Birmingham, but emissions restrictions meant that they weren’t available in the U.S.
Opel also used the GT as the basis for a number of one-offs, the most famous of which was the Diesel Rekordwagen, with special aerodynamic bodywork and a 2,068 cc (126 cu. in.) turbodiesel engine. In July 1972, the Rekordwagen averaged 119.3 mph (190.9 km/h) for 72 hours on Opel’s test track in Dudenhofen, setting a host of speed and endurance records.
In the U.S., the best-known tuned Opel GT was probably the one modified by Car and Driver magazine in 1970. Christened “J. Edgar Opel,” the C/D car had a blueprinted but emissions-legal engine with freer-flowing exhaust headers, making 100 net horsepower (75 kW), about 11 hp (8 kW) more than stock. The magazine also fitted a limited-slip differential with a 4.22 axle ratio (not on the U.S. options list, but homologated for competition), front and rear anti-roll bars, and a set of E60-15 Goodyear Wide Oval tires on Minilite wheels (the installation of which involved reshaping the inner fenders). The modifications trimmed more than a second from the GT’s 0-60 mph (0-97 km/h) times and improved cornering and braking grip considerably, but the big tires, extra unsprung weight, and aftermarket anti-roll bars created clearance problems, compromised ride quality and revealed the basic limitations of the front suspension geometry. The C/D car was eventually sold to artist Russ von Sauers, Jr. We don’t know if it still survives.
THE OPEL GT/J
While Opel made no move to offer any performance upgrades as factory options on the GT, the production car could have used the help. For the 1971 model year, GM mandated that all its U.S. engines be detuned to allow the use of lower octane low-lead and unleaded gasoline. Since the 1900S engine was octane sensitive (testers noted that it could ping even on 98 RON fuel), Opel reduced the compression ratio of federalized versions to only 7.6:1. Power nosedived, dropping from 102 to 90 gross horsepower (76 to 67 kW); SAE net output was now a meager 78 hp (58 kW). The lower compression ratio was accompanied by a switch from mechanical to hydraulic lifters, which were quieter, but cut the CIH engine’s usable rev range by about 600 rpm. The changes increased the GT’s 0-60 mph (0-97 km/h) times by more than a second and reduced top speed by about 5 mph (8 km/h).
The GT also faced another difficult new rival, this one from Opel itself. The new Manta coupe, Rüsselsheim’s answer to the Ford Capri, arrived for the 1971 model year, offering sporty styling (including a GT-like Kamm tail), similar performance, and much greater practicality for a significantly lower price. Despite its larger dimensions, the Manta wasn’t substantially heavier than the GT and actually handled better, thanks in large part to a new coil spring front suspension and anti-roll bars at both ends. Even in Europe, where the GT’s straight-line performance remained unchanged, it was hard not to see the Manta as a better value.
Opel GT production for 1971 dipped below 15,000 units, fewer than 1,100 of which were sold in Europe. To make matters worse, in 1970, Renault had purchased controlling interests in both Brissonneau & Lotz and Chausson. Since Renault considered the GT a competitor for its own Alpine A110, Opel was compelled to move production entirely in-house, an unwelcome extra expense for a low-volume model.
Hoping to boost sales by appealing to younger buyers, Opel introduced a new GT model at the 1971 Geneva auto show. Called the GT/J, it was comparable to American budget Supercars like the original Plymouth Road Runner: a brightly painted 1.9-liter Opel GT stripped of all nonessentials, including chrome trim and carpeting. Starting at 10,685 DM (about $3,070), the GT/J was still slightly more expensive than a Capri 2300GT, but considerably more affordable than the plusher GT-AL 1900S. The GT/J was not sold in the U.S., but it was moderately successful in Europe, accounting for 10,760 units through 1973.