The Isdera Imperator 108i was a low-volume German sports car built from 1984 to 1993. It grew out of the CW311 show car of 1978, which Eberhard Schulz, then a design engineer at Porsche, drew in his spare time using Mercedes-Benz parts. Mercedes had no interest in producing the car, so Schulz set up his own company, Isdera, to build it.
Isdera Imperator 108i at a glance
| Maker | Isdera, Leonberg, Germany |
|---|---|
| Production | 1984–1993 |
| Unveiled | Geneva Motor Show, March 1984 |
| Body | fibreglass on a tubular steel spaceframe |
| First engine | 5.0-litre Mercedes-Benz M117 V8 |
| Top speed | 283 km/h |
| 0–97 km/h | 5.0 seconds |
| Later engines | 5.6-litre M117; 5.6 and 6.0-litre AMG V8s, up to 390 hp |
| Drag coefficient | 0.311 |
| Doors | gullwing |
| Facelift | 1991, around 17 cars |
| Built | 30, of which 24 before the facelift |
History of the Isdera Imperator 108i
From CW311 to Imperator
The CW311 concept of 1978 was inspired by the gullwing Mercedes-Benz 300 SL and the Mercedes-Benz C111 experimental cars, and it had a drag coefficient of 0.311. It was built by Rainer Buchmann’s bb company using the big but heavy 6.9-litre Mercedes-Benz M100 V8 and other Mercedes parts. Buchmann is said to have fitted the Mercedes star without permission at first, later receiving authorization on condition that only one example carried it. Some sources have speculated that Mercedes allowed the badge to take press attention away from the new BMW M1. The one-off car appeared in the 1980 comedy Car-napping.
Mercedes-Benz allowed the use of its badge and name but had no interest in putting the CW311 into production, so Schulz founded Isdera and built the car under his own brand, which owns the trademarks to Imperator as a separate name. The production version, the Imperator 108i, was unveiled at the Geneva International Motor Show in March 1984. Compared with the show car it used two fixed headlamps in place of pop-up units and more conventional tail lights sourced from Mercedes-Benz.
Engineering
The Imperator 108i used a fibreglass body on a tubular steel spaceframe. The first cars had a 5.0-litre Mercedes-Benz M117 V8 giving a top speed of 283 km/h and 0–97 km/h in 5.0 seconds. As Mercedes-Benz developed more powerful V8s they were adopted in turn: a 5.6-litre M117, then 5.6 and 6.0-litre AMG units with 32-valve cylinder heads, raising output from 300 hp (304 PS) to 390 hp (395 PS). Unusually, the car had a rear-view periscope in place of conventional mirrors, which created a bulge in the roof, and it also had gullwing doors. The luxurious interior borrowed many components from the Porsche 928.
Facelift and the end
In 1991 the car was face-lifted: the pop-up headlamps of the 1978 show car returned, the body became more curvaceous, vents were added at the front near the doors, a NACA duct replaced three vents, the grille was redesigned and the indicators moved from the grille to the bottom of the headlamps, with wing mirrors optional. Around 17 cars were produced in this form. Production ended in 1993 when Isdera itself went out of business. Thirty examples were built in total, 24 of them before the facelift, and two were reportedly exported to Japan.
Design and features
- Gullwing doors: a direct link to the Mercedes-Benz 300 SL that inspired the original show car.
- Mercedes-Benz V8 power: from the 5.0-litre M117 to 6.0-litre AMG units of up to 390 hp.
- Periscope rear-view mirror: a roof bulge instead of door mirrors, an unusual solution kept for the whole run.
- Lightweight construction: fibreglass body over a tubular steel spaceframe.
- Porsche 928 interior parts: switchgear and trim borrowed from the German rival.
Isdera Imperator 108i versions
- Pre-facelift cars (1984–1991): 24 built, with fixed headlamps.
- Facelifted cars (1991–1993): around 17 built, with pop-up headlamps and a smoother body.
- 5.0-litre cars: the original M117 V8, 283 km/h.
- 5.6-litre cars: Mercedes-Benz and AMG versions of the M117.
- 6.0-litre AMG cars: the most powerful version, 390 hp.
The Imperator was replaced in the range by the one-off Commendatore 112i, and it followed the earlier Spyder. More cars are in the Isdera collection.
Video: Isdera Imperator | GRIP #250
Video by GRIP – Das Motormagazin on YouTube.
Sources
- Isdera Imperator 108i, English Wikipedia: history, engineering, production
- Isdera, German Wikipedia: company history and model timeline
