Opel 2000-GSI 16 Valve "Superboss" 1991 Model
Opel 2000-GSI 16 Valve "Superboss" 1991 Model
The first Opel car to carry the Kadett name was presented to the public in December 1936 by Opel's Commercial-Technical director, Heinrich Nordhoff , who would in later decades become known for his leadership role in building up the Volkswagen Company.
The mastermind behind the Superboss was Rolf Mentzel, the then Delta’s manager of product engineering and quality assurance.
Mentzel headed overseas with an extensive shopping list after being instructed to make sure Briggs retained his hard-fought ‘A1’ race number at the end of the 1990 season. This was in the face of the looming challenge of the lightweight iS and the rumoured (and ultimately stillborn) Spitze Golf. He visited tuning and suspension specialists Irmscher, camshaft expert Schrick as well as Aluette, who made some very tasty lightweight wheels.
Mentzel returned with hot cams, springs, ventilated discs (from the Opel Omega sedan) and wheels with a distinctive five-spoke pattern and a powder-coated anthracite finish. What he didn’t find overseas was a suitable limited-slip diff or an exhaust system.
André Verwey, already acclaimed as a brilliant engineer and innovator, was approached to build a differential and he came up with a design which allowed for two settings – road and track. Needless to say, all cars were sold with the higher preload though dealers could theoretically change it to the more forgiving position if the customer so desired. The same applied to the camshaft phasing, which could be set to give less overlap and a smoother idle. But a Superboss without a lumpy, slightly fluffy idle wouldn’t be a Superboss.
The exhaust was developed locally after ‘many long, long nights’ on the dynamometer, with the objective being to get a power curve free of dips and gullies plus plenty of torque lower down. Another key player in this process was a German named Rolf Deubel, whose company Promotec was one of the pioneers of chip tuning.
By the time they had finished burning the midnight oil and produced a pile of tested and discarded exhaust systems, they had what they were looking for
Road versions were signed off with 125kW at 6 200r/min and 228Nm at 4 800, and with an on-the-road mass of a tonne (give or take) it had a very healthy power to weight ratio. It was that magical Verwey diff that ultimately gave the car its character
Warning: the Opel Superboss was never designed to be mixed with tequila, and that bullet shape and the sweet power its engineers threw under the bonnet really come together when you put your foot down on the pedal. Although the arguments between Superboss owners and then-model Golf GTI (jumbo) owners continue to this day, it’s sufficient to say this car really is a speeding bullet, and its acceleration and glide can still be alarming for newcomers.
Probably made most famous as the car of choice of Group N Saloon Car Championship racer Mike Briggs, this model pushed the term “standard production” to new heights when it was released. The car won the Group N or “Showroom Class” championship three years in a row. Manufactured between 1990 and 1994.
The Superboss was an exclusively South African development of the standard Opel Kadett, and only 244 were ever made.
Today it’s quite obvious that the Superboss helped give rise to modern, front-wheel, smoking hot hatches like the Renault Megane R26 and even the Mini Cooper GP. Extremely rare at the time, the Superboss shares a limited slip differential with modern performance front wheel drive hatches.
How would you spot a fake Superboss? One way would be to run your hand around the inside of the wheel arches and feel whether they have been properly flattened to cope with the combination of a ride height dropped by 20mm and the wide tyres. Back in 1990, a 195/50 VR15 was considered big. It was only after the first cars came down the line that the clearance issue became apparent, and later ones had the arches rolled before being painted. You could also remove the carpet and check whether the sound-deadening material has been left off.
But the surest test is to look at the VIN plate: if ‘S’ appears at the end of the string of letters that prefix the actual chassis number, you’re on the right track as this is difficult to forge.
The Superboss was one of the last truly hardcore South African homologation specials, and air conditioning was extremely rare. Bearing in mind that the back windows didn’t open.
Model: 1991
Transmission type: Manual
Vehicle colour: Red
Mileage: 137689
Interior colour: Cloth
Number of doors: Two Doors
Convertible: No
Driver side: Right Hand Side
Fuel: Petrol
Motor size (CC): 2,0 Litre
Owner's Manual: No
Service History: Partial
"Born on the racetrack" is an often-used term when it comes to high-performance cars, but few road machines can rightfully lay claim to that description. The Opel Kadett GSi 16V S, better known as the "Superboss" is just such a machine. Developed with the single purpose of annihilating the iconic BMW 325iS in local Group N racing, it has become an enduring South African legend