The Grinnall Scorpion is a small-series sports car built by Grinnall Specialist Cars in England since 1992. Two models are available, the three-wheeled Scorpion III and the four-wheeled Scorpion IV, with the Roman numerals referring to the number of wheels rather than being mark designators. The III is fitted with BMW motorcycle engines, while the IV is typically equipped with automobile engines from Audi.

Scorpion III

The Grinnall Scorpion III is a reverse trike, with two wheels at the front and one at the rear, which is a better-handling configuration than one wheel at the front. Designed in 1991 by Steve Harper, the Scorpion III features a GRP body tub which is bonded to a space frame chassis underneath, and employs a BMW K-series motorcycle engine as its power plant. The engine, gearbox and final drive from the motorcycle are utilised with a special rear wheel which is fitted with a car tyre, as are the front wheels. It has a very good

power-to-weight ratio Power-to-weight ratio (PWR, also called specific power, or power-to-mass ratio) is a calculation commonly applied to engines and mobile power sources to enable the comparison of one unit or design to another. Power-to-weight ratio is a measurement ...

which endows it with excellent performance. The rear wheel is of a smaller circumference than the bike's wheel so the gearing is optimised for a lower top speed of around with 0-60 mph (97 km/h) taking around 6 seconds when using a K1100 engine. Any BMW K engine can be used, from a 750 cc 3-cylinder, to a 1200 cc, 4-cylinder, giving power outputs from to . The motorcycle sequential gearchange is retained and operated via a gear shift inside the cockpit and requires a forward or backward movement to change gear. The brake, accelerator and clutch operate as per a car and are adjustable for reach to accommodate drivers of different size. The seat and steering wheel are fixed in position. There are two seats, and there is provision above the engine to accommodate some luggage which is roughly equivalent to two sports bags. Handling is generally considered to be good due to the low centre of gravity and wide front track (approx ) although care is needed when roads are wet. A turbocharged engine kit is available from BBR racing, which increases power to around for the 1100 cc engine. The trikes are sold as complete kits with everything needed to finish including washers, ty-wraps etc. or as completed vehicles. They are essentially recreational vehicles which offer high performance but lack the practicality of a conventional car. In 2008 Grinnall offered the Scorpion III with the BMW K40 engine which Grinnall claims is producing over at the rear wheel.

Scorpion IV

The Grinnall Scorpion IV is a car made by Grinnall Specialist Cars. It was designed by Steve Harper to be essentially similar in appearance to the Scorpion III but with an extra wheel and slightly larger dimensions. The Scorpion IV is an open

sports car A sports car is a type of automobile that is designed with an emphasis on dynamic performance, such as Automobile handling, handling, acceleration, top speed, the thrill of driving, and Auto racing, racing capability. Sports cars originated in ...

constructed from

fibreglass Fiberglass (American English) or fibreglass ( Commonwealth English) is a common type of fiber-reinforced plastic using glass fiber. The fibers may be randomly arranged, flattened into a sheet called a chopped strand mat, or woven into glass c ...

covered

steel Steel is an alloy of iron and carbon that demonstrates improved mechanical properties compared to the pure form of iron. Due to steel's high Young's modulus, elastic modulus, Yield (engineering), yield strength, Fracture, fracture strength a ...

with a space frame

chassis A chassis (, ; plural ''chassis'' from French châssis ) is the load-bearing framework of a manufactured object, which structurally supports the object in its construction and function. An example of a chassis is a vehicle frame, the underpart ...

. Power is provided by an

Audi Audi AG () is a German automotive manufacturer of luxury vehicles headquartered in Ingolstadt, Bavaria, Germany. A subsidiary of the Volkswagen Group, Audi produces vehicles in nine production facilities worldwide. The origins of the compa ...

1.8-litre turbocharged petrol engine driving a 6-speed gearbox. The standard engine produces but this can be tuned to provide more and Grinnall offer options to increase this to over .Grinnall only quotes computer-simulated acceleration figures at present and these are 0-60 mph 3.7s; 0-100 mph 7.9s; and 30-70 mph 2.7s. Midrange acceleration was predicted to be 40-80 mph in 3rd in 3.1sec, 40-100 mph in 4th in 6.8sec

Notes

External links

Grinnall Specialist Cars Ltd.
official website
Grinnall Scorpion Owners Club

Scorpion IV
{{Webarchive, url=https://web.archive.org/web/20170829203109/http://www.grinnallcars.com/cars/scorpion-iv/ , date=29 August 2017

Scorpion Scorpions are predatory arachnids of the Order (biology), order Scorpiones. They have eight legs and are easily recognized by a pair of Chela (organ), grasping pincers and a narrow, segmented tail, often carried in a characteristic forward cur ...

Three-wheeled motor vehicles

Scorpion III

Scorpion IV

Notes

See also

External links