The Opel Kadett Superboss Legend Lives On

This car was built with a single purpose – to dominate.

The legendary BMW E30 325iS is really sought after today worldwide, but in the late ’80s it was already an icon of South African motorsport, where it dominated the local Group N racing series. At the time, the local arm of General Motors didn’t enjoy BMW’s countless victories, so they conjured up a plan to build something capable of dethroning the 325iS.

And this is what they came up with: The Opel Kadett GSi 16V S, better known as the Superboss.


The Superboss wasn’t South Africa’s first performance-oriented Kadett. Prior to this model, there were various versions of the 2.0-litre hatchback spanning two generations of the vehicle. First was the SOHC 8V GSi, which earned the nickname Boss, followed by a DOHC 16V variant, which went by the name Big Boss.


For the Superboss to be homologated for Group N racing, 500 road-going examples needed to be built. This is one of those cars.


To bring the Kadett’s spec up to a level where it could rival the 325iS, Opel took the existing C20XE  engine – a 2.0L DOHC 16-valve four-cylinder unit good for 115kW (152hp) – and made a few key changes. A Cosworth-designed cylinder head with 276-degree Schrick cams and sodium-filled valves, forged pistons, and higher compression got the party started, with Bosch Motronic fuel injection, a revised intake, 4-to-1 exhaust manifold running into a free-flow system, and a Promotec ECU chip finishing things off.

The result of all this was 125kW (170hp), not a huge number by today’s standards, but a decent amount in 1990. More impressive was the maximum torque figure of 228Nm, which equated to a naturally aspirated world record at the time of 114Nm per litre. In fact, this accolade stood until 2009 when it was finally eclipsed by the Ferrari 458 Italia (117Nm per litre).


The Superboss was also equipped with a limited slip differential specially designed and built in South Africa by André Verwey. This was a vital part, which really helped the car put its power down on the road.


Another exclusive feature was the wheels – five-spoke Aluetts in a 15×7-inch fitment.


One interesting thing about the Superboss was its subtle exterior styling, which made the model a real sleeper on the street.


This thinking was carried through to the interior, which was higher spec than other Kadett models but no-frills at the same time.

The track version of the Superboss – the reason why it was conceived in the first place – was something special, as you’ll see in this historic race clip of Mike Briggs throwing his car around the Kyalami racetrack. Briggs won the 1991 and 1992 championships for Opel with this car.

Our road car feature subject is owned by the team at SentiMETAL, and was found in a very sad state. They wanted to restore it to pristine condition so they enlisted the services of Werner Meyer, a highly-regarded local restorer of these cars.

In its lifetime the car had so many incorrect parts fitted, so it received a full nut and bolt restoration, including a respray and complete rewire. The team even did a little documentary on this special build.


Thirty-odd years after it broke cover, the Superboss is still an immensely cool car. It made a real name for itself in period, and I’m sure in the years to come it’ll only become more and more sought after than it already is in South Africa.

Stefan Kotzé
Instagram: stefankotzephoto



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Didn't even read the article, came straight to the comments to submit my approval!! WE NEED MORE COOL OLD SCHOOL OPELS/VAUXHALLS!! :D


Thank you sir!


I agree with this and point towards Australia and their V8 Holden Commodores of yesteryear!

Matthew Adam Berman

About time the superboss got featured! amazing example of the breed!


Yeah it's a really badass car man!


Please: more of this, less stance


Now this is what you call a hot hatch!
Love the old Opels/Vauxhalls!


Awesome photography and write up on the Opel Kadett GSI Superboss. A legendary Hot Hatch that took on the 325iS and beat them at their own game. Keep up the awesome work Stefan Kotze


Thanks Arief! Glad you dig it!


In the UK this was the Astra GTE and in the 80's it was almost impossible to go faster. Then they all rusted away and had their engines stolen for Nova's and Corsa's.


Im privileged to be working at the exact same plant were the super boss was built.

There is a office with really nice posters of the super boss,but its been renovated.

Oh and stef,it was Delta..not general motors,this car was strictly S.A made.


That must've been awesome man!

Yeah I know locally it was Delta and it was our local only gift :)

Delta was still under the General Motors umbrella though I assume?


Here in Brazil we had the Kadett GSI in the 90's. A very nice hot hatch that had the VW Gol GTi and Escort XR3 to fight with on the streets. The Recaro seats(every cool car on Brazil had them at the time) on them were amazing, and also had a convertible version. Today is very hard to find a nice one.


This is really cool, seeing factory racers that are well kept and cared for by there owners. I take it that not many of these cars survived so therefore its even more of a rare sight to see one in such good condition.

I really appreaciate the lengths the owners has gone to, to keep it mint.

Seeing these vehicles remains a time capsule experience, things we only saw on grainy old VHS uploaded by people who are much older then any of us on this site.

Its really a treat for the eyes.

Something worth finding, is an open tigra ice cup race car, 4WD, maybe, perhaps. *mouth racecar noises*



One car from SA I'd really like an article about is the Kadett/Astra 200ts, especially considering a lot of stuff on the internet is just shodily written articles and old photos or ones from used car ads.


Yes!!! The mk4 and mk5 GTi killer from the 90s. I see a lot of people commenting on other 2.0 16v from other countries, but the SB was not the same, all others had a 110kw tag, but the SB had 276° Schick cams, and LSD and a different exhaust and different tuning and was tagged with a 125kw output. The SB is not like other international 2.0 16vs, but yes, We need a 200ts feature!!


I've already shot a brilliant, completely stock red TS. When I get some time you'll see it on here first!


Stef. You legend!!! You should try to do a South African legends series if you can, of cars like the Capri Perana, Firenza Can-Am, Alfa GTV 3.0, Sierra/Sapphire XR8, 745i(The M88 version if you can find one) if possible, before you do the stock 200ts article, could you find a modded one to feature as well? I know that I'm asking a lot. These are all high hopes and I know that it's not easy, but I have to take a chance. Thanks for all the great articles.


My ex-boss had a 333i when he lived in Harding, but he claimed that his had an M88(E28 M5 motor) in it from factory and some bonnet vents, I don't know how true this is, have you ever heard of this? He said that at the time it was supposedly one of 6 and had pictures of it but not the engine bay. So not sure if true or if he was BS'ing me.


This makes my inner mechanic cry the tears of joy!