Colotti Trasmissioni (Colotti Transmission) is an Italian mechanical engineering firm located in Modena, Italy. It specializes in gears, limited-slip differentials and transmission systems for racing cars.
Valerio Colotti, who is famous as the chassis designer/engineer of Maserati 250F, started his own company called Tec-Mec in 1958. One of the first achievements was the design and manufacture of differential gear set/housing for Rob Walker, which solidified his reputation in the Grand Prix circles.
After building a GP car for Jean Behra, which became known as Behra-Porsche, Colotti built his own Grand Prix car named Tec-Mec F415, based on Maserati 250F in 1959, with Fritz d'Orey as the driver who finished 10th at 1959 French Grand Prix. At about the same time, Alf Francis, the Chief Engineer at Rob Walker Racing, started working with Colotti, changing the Tec-Mec name to Colotti-Francis.
Colotti-Francis was responsible for a Formula Junior car named T.C.A.(Trips Colotti Automobili) built for Graf von Trips, but this project ended with Trips' death at 1961 Italian Grand Prix held at Monza, where his Ferrari 156 collided with Jim Clark's Lotus 21, when a 3rd-place finish would have secured Count Trips the first ever Grand Prix World Championship title for a German, which did not materialize until 1994.
Rob Walker asked Colotti to analyse and modify the front suspension of two Lotus racing cars belonging to Rob Walker Racing, and the plausible result prompted Rob Walker to let Colotti review the design of his own Grand Prix car, Walker Special, which was being built at the time. With the new 1.5 Liter Formula One regulation going into effect for the 1960 season, Colotti designed and built T.32 5 speed and T.34 6 speed transaxles, which weighed less than 35 kg, suitable for lower-torque high-rev 1.5 Liter engines mounted behind the driver.
Outside of racing field, Colotti worked under the name G.S.D. (Gear Speed Developments), such as on a transmission of a Hovercraft for Britten-Norman of Isle of Wight, and a power take-off/transfer system for the mixer drum on Cement mixer trucks, which replaced the long chain drives previously used.
Francis and Colotti knew the shortage of limited slip differential manufacturers was a big hardship experienced by Grand Prix constructors then. For example, Colin Chapman had his in-house engineers, Keith Duckworth and Mike Costin, develop the sequentially shifting transaxles for Lotus 16 and Lotus 18, which he had originally asked Richard Ansdale and Harry Mundy to design for Lotus 12. But despite these transaxles being unique and innovative, they still incorporated limited slip differentials made by ZF of Germany, which was about the only source, and the technology used was an old slip-limiting principle invented by Ferdinand Porsche in the 1930s for Auto Union GP cars.
Colotti, whose company name had become Colotti Trasmissioni (Colotti Transmission) by this time, researched the issue, developed and patented a unique mechanism called Coppia-Frenata to limit the slip on the differential gears. This limited-slip differential became popular among the Formula 1 and other racing teams, being one of the few viable alternatives to the ZF product.
In 1962, Colin Chapman asked Colotti to design and build a transaxle for a car designed for Indianapolis 500. This high torque specification 4 speed T.37 transaxle was designed for Small Block Ford-based engines.
On Lotus 29, which had a Ford 256 CID all-aluminium OHV pushrod V-8, based on their iron Fairlane 260 CID V-8, the T.37 was used with 2 speeds blanked off.  And the car went on to score the 2nd and 7th-place finishes at 1963 Indy 500 in the hands of Jim Clark and Dan Gurney, respectively.
Gianpaolo Dallara asked Colotti Trasmissioni to develop and manufacture a racing version of the transaxle for Lancia Montecarlo, which was to be Fiat Group's FIA Group 5 weapon. Equipped with a new quick-response limited-slip differential called Duo-Block, this transaxle was very successful by winning the World Endurance Championship in 1980 and 1981, and Duo-Block was patented. 
Colotti Trasmissioni was also active in the Rally sector, by developing a new kind of limited-slip center differential for four wheel drive competition cars. This torque splitting/proportioning device is patented as Split-Diff.
Valerio Colotti having worked for Ferrari in the late 1940s and early 1950s, and having engineered the chassis and transmission of their first GP car of its own design under Enzo Ferrari, Aurelio Lampredi and Gioacchino Colombo, Piero Ferrari asked Colotti Trasmissioni to build an exact replica of Ferrari 125, with the original engine and drawings provided by the Maranello factory. This first-ever Ferrari-built Grand Prix car had been lost, and the completed replica currently resides in Museo Ferrari in Maranello, alongside newer Ferrari F1 machines.
Alkè is an Italian truck, electric vehicles, and diesel engine manufacturer based in Padua, Italy. The company was created in 1992.B Engineering
B Engineering is a small-volume automobile manufacturer located in Italy. It is made up of several former employees of the Bugatti firm when it was under the leadership of Romano Artioli.Borrani
Ruote Borrani S.p.A. (established 1922 in Milano) is an Italian manufacturer of wheels, famous for supplying Rudge-Whitworth design single-nut lockable wire wheels to many Italian racing cars and luxury cars until the 1960s.Brembo
Brembo S.p.A. is an Italian manufacturer of automotive brake systems, especially for high-performance cars and motorcycles based in Bergamo, near Milan.Carrozzeria Barbi
Carrozzeria Barbi is an Italian bus manufacturer, with headquarters in Mirandola, near Modena.Carrozzeria Boneschi
Carrozzeria Boneschi S.r.L. (established 1919 near Milano) is an Italian coachbuilder, mainly of commercial vehicles. Until 1960, the company was mostly involved with automobile manufacturers such as Talbot, Rolls Royce, Alfa Romeo, Lancia and Fiat. It was established in Milano by Giovanni Boneschi, moving to Cambiago in (1933). The factory was rebuilt after World War II (1946), after which Boneschi died. Among its designers and directors in the later years was Dr. Bruno Pezzaglia.Casalini
Casalini is an Italian company, founded by Giovanni Casalini in 1939, that makes mopeds and microcars. Casalini S.r.l. is the oldest microcar producer in the world. The factory is situated in Piacenza.
The current range of Casalini microcars have a bodies of reinforced fibre glass plastic. The engine is a 635 cc diesel produced by Mitsubishi, with 3.9 kW (5.3 PS).FCA Italy
FCA Italy S.p.A. (formerly Fiat Group Automobiles S.p.A.) is the Italian subsidiary of the Italian-American automaker Fiat Chrysler Automobiles, dedicated to the production and selling of passenger cars and light commercial vehicles and headquartered in Turin, Italy.Fioravanti (automotive)
Fioravanti is an Italian automotive design studio in Moncalieri outside the city of Turin. The company began in 1987 as an architectural practice working on projects in Japan, and since 1991, it has focused its activities on automotive design.
Fioravanti was founded by C.E.O. Leonardo Fioravanti, who worked twenty-four years with Pininfarina on such vehicles as the Ferrari Daytona, Ferrari Dino, Ferrari 512 Berlinetta Boxer, the Ferrari 308 GTB, Ferrari 288 GTO and the Ferrari F40.Fornasari
Fornasari was an Italian car manufacturer that was created in 1999 by Giuseppe Fornasari. The company made sports cars and SUVs. On 9 September 2015 Fornasari was declared bankrupt by the Tribunal of Vicenza.Giottiline
Giottiline is an Italian mobile home manufacturer and producer of the small scissor doored minicar the Giottiline Ginko. It produces also recreational vehicles.Grecav
Grecav is an Italian automobile and farm machinery manufacturer from Gonzaga, province of Mantua. The company produces, among other things, light motor vehicles. The company was founded in 1964 by Cav. Bruno Grespan (current President) through the merger of two companies; Fratelli Grespan S.n.c. (founded in 1956) and Cavalletti S.n.c. (founded in 1922).I.DE.A Institute
I.DE.A Institute (acronym, Institute of Development in Automotive Engineering) is an automobile design and engineering company in Turin, Italy, founded in 1978. The Rieter Holding Ltd took full control of the company in 2002. In 2010, Rieter sold the company to the Swiss investment group Quantum Kapital AG.Italcar
Italcar is an Italian company based in Turin who produces and distributes electric vehicles. The vehicles carried by Italcar range from golf carts to utility to neighborhood electric vehicles. The vehicles can be used for luggage, as a shuttle, maintenance, or for recreational activities like golf.OZ Group
OZ Group is an Italian company founded in 1971 that produces car and motorcycle wheels, specifically alloy wheels. They are an OEM supplier to a number of manufacturers in addition to aftermarket sales and are a prominent wheel supplier in motorsport.SPICA
SPICA S.p.A. (Società Pompe Iniezione Cassani & Affini) was an Italian manufacturer of fuel injection systems.Tec-Mec
Tec-Mec (full name Studio Tecnica Meccanica) was a Formula One constructor from Italy. Founded by former Maserati designer Valerio Colotti in 1958, they participated in a single Grand Prix, scoring no World Championship points.
Tec-Mec used an improved, lightened version of the Maserati 250F, named the F415. The car was upgraded by the 250F's designer, Colotti, and financed by Lloyd Casner of Camoradi International. The team made its single outing in the 1959 United States Grand Prix, but the car, driven by Fritz d'Orey lasted six laps before retiring, having qualified 17th on the grid ahead of only the midget racer of Rodger Ward.Colotti sold the design studio at the end of the year, and the company continued to produce cars for the Formula Junior series.Valerio Colotti
Valerio Colotti (Modena, 1925 - 19 January 2008) was an Italian automotive engineer, known for his early work with Ferrari and Maserati chassis and transmission systems.
He joined Ferrari in 1948, working under Aurelio Lampredi, followed by employment with Maserati (1953–1957), until the company dropped factory works racing. In 1958 he started his own company, known as Tec-Mec (Studio Tecnica Meccanica).
Tec-Mec, assisted by Giorgio Scarlatti, attempted at the tipo F/415 Formula One car, mostly based on the Maserati 250F, in which Colotti had been deeply involved. There was cooperation with Behra-Porsche (1959) and others such as
Stirling Moss, who failed in his racing with Cooper T51, fitted with Colotti's, unfortunately rather unreliable, gearboxes.
Colotti's cooperation with Alf Francis lead to the widely used in competition Colotti-Francis gearbox systems.
With Wolfgang von Trips he designed the Trips-Colotti-Auto Union (TCA), and later their transmissions
were used in Alfa Romeo 33 Stradale (1967).
The company is now called Colotti Trasmissioni and is run by his sons Marco and Paolo.