Forced induction in motorcycles is the application of

forced induction In an internal combustion engine, forced induction is where turbocharging or supercharging is used to increase the density of the intake air. Engines without forced induction are classified as naturally aspirated. Operating principle Overvi ...

(

turbocharger In an internal combustion engine, a turbocharger (often called a turbo) is a forced induction device that is powered by the flow of exhaust gases. It uses this energy to compress the intake gas, forcing more air into the engine in order to pro ...

s or

supercharger In an internal combustion engine, a supercharger compresses the intake gas, forcing more air into the engine in order to produce more power for a given displacement. The current categorisation is that a supercharger is a form of forced induct ...

s) to a

motorcycle engine A motorcycle engine is an engine that powers a motorcycle. Motorcycle engines are typically two-stroke or four-stroke internal combustion engines, but other engine types, such as Wankels and electric motors, have been used. Although some moped ...

. Special

automotive engineering Automotive engineering, along with aerospace engineering and naval architecture, is a branch of vehicle engineering, incorporating elements of mechanical, electrical, electronic, software, and safety engineering as applied to the design, manufactu ...

and

human factors Human factors and ergonomics (commonly referred to as human factors) is the application of psychological and physiological principles to the engineering and design of products, processes, and systems. Four primary goals of human factors learnin ...

considerations exist for the application of forced induction with motorcycles, compared to other forms of motorized transportation.

Forced induction in production motorcycles

Prior to the late 2010s, forced induction was only used on a handful of production motorcycles, all from

Japanese Big Four The Japanese Big Four are the large motorcycle manufacturing companies of Japan: * Honda, which produces motorcycles since 1946. * Suzuki, which produces motorcycles since 1952. * Kawasaki, which produces motorcycles since 1954.CX 500 Turbo / 1983 650 Turbo *Yamaha 1982-1983 XJ 650 Seca Turbo *Suzuki 1983 XN 85 Turbo *Kawasaki 1983-1985 GPZ750 Turbo Honda CX650 Turbo had a 674 CC, 100 BHP V-twin engine. It is contestably the best forced induction production bike of the 1980s from any Japanese manufacturer. The 1983 model Honda CX650 Turbos had solved the lag problems that earlier models like the CX500 Turbo had encountered. To rectify turbo lags capacity and compression ratio was raised from 7.2:1 to 7.8:1. Additionally, in 1978 Kawasaki offered the Z1R-TC, a semi-production model built by Turbo Cycle Corporation and sold through Kawasaki dealers. This is generally considered to be the first Japanese turbocharged motorcycle. The Honda, Kawasaki and Suzuki bikes were all listed on a

State Farm State Farm Insurance is a large group of mutual insurance companies throughout the United States with corporate headquarters in Bloomington, Illinois. Overview State Farm is the largest property and casualty insurance provider, and the la ...

insurance "

blacklist Blacklisting is the action of a group or authority compiling a blacklist (or black list) of people, countries or other entities to be avoided or distrusted as being deemed unacceptable to those making the list. If someone is on a blacklist, t ...

" published by ''

American Motorcyclist ''American Motorcyclist'' is an American magazine published monthly by the American Motorcyclist Association, covering issues of importance to its members, including legislation and regulations, touring, trail riding, motocross, enduros, road rac ...

'' in 1989.

21st century

A scooter with a supercharger, the Peugeot JetForce Compressor, was available in late 2003. Kawasaki confirmed it would be re-entering the market with the supercharged

Kawasaki Ninja H2 The Kawasaki Ninja H2 is a " supercharged supersport"-class motorcycle in the Ninja sports bike series manufactured by Kawasaki, featuring a variable-speed centrifugal supercharger. Its namesake is the 750 cc Kawasaki H2 Mach IV, an ...

, announced in October, 2014. This was followed by the H2 SX SE sports tourer, and for 2020 Kawasaki announced a new naked model, designated Z H2.

Engineering and usability challenges

Designers have been able to address packaging issues and fit turbochargers even in fully faired motorcycles.

Turbo lag In an internal combustion engine, a turbocharger (often called a turbo) is a forced induction device that is powered by the flow of exhaust gases. It uses this energy to compress the intake gas, forcing more air into the engine in order to pro ...

was noted as a problem with all four Japanese turbos of the 1980s by several critics. quotes an expert's dry summary of these bikes' "difficult power characteristics" Motorcycle engineering expert and journalist Kevin Cameron has said that

turbo lag In an internal combustion engine, a turbocharger (often called a turbo) is a forced induction device that is powered by the flow of exhaust gases. It uses this energy to compress the intake gas, forcing more air into the engine in order to pro ...

is a critical problem with turbocharger applications on motorcycles: " less you are a pure drag racer, most of your riding will be off-boost. The lower your compression ratio, the less snap your bike will have...don't expect your turbo bike to be much use in sportbike-type canyon racing." Using a

variable-geometry turbocharger Variable-geometry turbochargers (VGTs), occasionally known as variable-nozzle turbines (VNTs), are a type of turbochargers, usually designed to allow the effective aspect ratio of the turbocharger to be altered as conditions change. This is done ...

can mitigate turbo lag, but has not yet been used in series production (the first mass market application was to late 1980s automobiles; see Variable-geometry turbocharger#History and examples of use). Writer Mick Walker has listed turbo lag along with other challenges like a higher

center of gravity In physics, the center of mass of a distribution of mass in space (sometimes referred to as the balance point) is the unique point where the weight function, weighted relative position (vector), position of the distributed mass sums to zero. Thi ...

and heat transfer to rider due to turbocharger and associated exhaust plumbing. Bennett noted excessive weight and complexity in addition to weak bottom-end performance. The German magazine '' Motorrad'' said in 2014, that a turbocharger would probably never be practical on mass market motorcycles due to cost of high-tech materials able to withstand the high temperatures of a variable geometry turbocharger, plus weight and space considerations, though they left the door open for a good supercharged solution.

Emissions

Emissions considerations, driven in particular by carbon dioxide limits in the

European emission standards The European emission standards are vehicle emission standards for pollution from the use of new land surface vehicles sold in the European Union and EEA member states and the UK, and ships in EU waters. The standards are defined in a ser ...

, are leading motorcycle manufacturers in the 2010s to reconsider applications of forced induction.

In racing

In road racing, superchargers were not uncommon in the 1930s, and machines originally built for road racing also set many land speed records (see the list below for examples). Motorcycle racing in Europe went through a hiatus during the 1940s as

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

and its aftermath, and racing only restarted in 1946. That same year, forced induction was banned from road racing by the

Fédération Internationale de Motocyclisme The Fédération Internationale de Motocyclisme (FIM; en, International Motorcycling Federation) is the global governing/sanctioning body of motorcycle racing. It represents 116 national motorcycle federations that are divided into six regiona ...

(FIM), effectively relegating it to specialized forms of racing and speed record runs, discussed further below. Rules from the FIM and other sanctioning bodies cover aspects of motorcycle design as diverse as

motorcycle fairing A motorcycle fairing is a shell placed over the frame of a motorcycle, especially racing motorcycles and sport bikes, to deflect wind and reduce air drag. The secondary functions are the protection of the rider from airborne hazards and wind-induc ...

coverage,

gasoline direct injection Gasoline direct injection (GDI), also known as petrol direct injection (PDI), is a mixture formation system for internal combustion engines that run on gasoline (petrol), where fuel is injected into the combustion chamber. This is distinct fro ...

, and the use of

dual-clutch transmission A dual-clutch transmission (DCT) (sometimes referred to as a twin-clutch transmission) is a type of multi-speed motor vehicle, vehicle Transmission (mechanics), transmission system, that uses two separate clutches for odd and even gear train, g ...

s, and may influence street bike design by setting public expectations.

Drag racing

Specialized motorcycles used in

drag racing Drag racing is a type of motor racing in which automobiles or motorcycles compete, usually two at a time, to be first to cross a set finish line. The race follows a short, straight course from a standing start over a measured distance, most c ...

, called

dragbike Motorcycle drag racing (also known as "sprints") involves two participants lining up at a dragstrip with a signaled starting line. Upon the starting signal, the riders accelerate down a or long, two lane, straight paved track where their elapsed t ...

s, are an application for forced induction, including nitrous oxide and multistage turbochargers. The first dragbike to run the quarter-mile in under 7 seconds was using a

Roots-type supercharger The Roots-type blower is a positive displacement lobe pump which operates by pumping a fluid with a pair of meshing lobes resembling a set of stretched gears. Fluid is trapped in pockets surrounding the lobes and carried from the intake sid ...

Motorcycle clubs

At least one

motorcycle club A motorcycle club is a group of individuals whose primary interest and activities involve motorcycles. A motorcycle group can range as clubbed groups of different bikes or bikers who own same model of vehicle like the Harley Owners Group. Ther ...

, Turbo Motorcycle International Owners Association, has been formed to support turbo motorcycle enthusiasts.

Notable prototypes and record setters

BMW WR 750 The BMW WR 750 was a supercharged racing motorcycle from BMW with two-cylinder, four-stroke flat twin engine starting production in the year 1929. History The idea to equip the flat twin engine with a supercharger came from the designer of the ...

, supercharged boxer twin, set several

Motorcycle land speed record The motorcycle land-speed record is the fastest speed achieved by a motorcycle on land. It is standardized as the speed over a course of fixed length, averaged over two runs in opposite directions. AMA National Land Speed Records requires 2 passes ...

s 1930–1935 * BMW Type 255 RS 500, supercharged boxer twin, ridden by

Georg Meier Georg "Schorsch" Meier (; 9 November 1910 – 19 February 1999) was a German motorcycle racer famous for being the first foreign winner of the prestigious Senior TT, the Blue Riband race of the Isle of Man TT Races, in 1939 riding for the ...

to first

Isle of Man TT The Isle of Man TT or Tourist Trophy races are an annual motorcycle racing event run on the Isle of Man in May/June of most years since its inaugural race in 1907. The event is often called one of the most dangerous racing events in the world ...

win by non-Briton in 1939; auctioned in 2014 for the second-highest price ever for a motorcycle *

Gilera Gilera is an Italian motorcycle manufacturer founded in Arcore in 1909 by Giuseppe Gilera (1887–1971). In 1969, the company was purchased by Piaggio. History In 1935, Gilera acquired rights to the Rondine four-cylinder engine. It was, at ...

Rondine, 4-cylinder DOHC, supercharged,

Piero Taruffi Piero Taruffi (12 October 1906 – 12 January 1988) was a racing driver from Italy. Sports car career Taruffi began his motorsport career racing motorcycles. He won the 1932 500cc European Championship on a Norton and in 1937 set the motorcycle ...

set land speed record with it in 1937 *

Fritz Egli Fritz W. Egli, (born June 30, 1937 in Zurich) is a Swiss former motorcycle racer. He is known as a motorcycle frame specialist, and engine tuner. History Egli founded his motorcycle speed shop in 1965. One of his first vehicles included a Vincen ...

's turbo Kawasaki, covered in August 1988 ''Cycle'' as "world's fastest?" * Bill Warner's 300+ mph turbo Hayabusa, set speed record for non-enclosed bike in 2011. Warner crashed it in 2013, resulting in his death. *

Cabin motorcycle A cabin motorcycle is a fully or semi-enclosed motorcycle. They first appeared in the 1920s In parts of Eastern Europe, they are known as dalniks. These fully enclosed non-production motorcycles used for land-speed record-breaking attempts, su ...

s: **

Peraves Ecomobile Peraves AG was a Swiss manufacturer of high-end aerodynamically-enhanced cabin motorcycles. It won the Automotive X Prize for its entirely electric X-Tracer in 2010. By 2019 it had declared bankruptcy. History Peraves AG was founded in 1972 by ...

, available with turbocharged BMW K1200

inline-four engine A straight-four engine (also called an inline-four) is a four-cylinder piston engine where cylinders are arranged in a line along a common crankshaft. The vast majority of automotive four-cylinder engines use a straight-four layout (with the ...

; "the only motorcycle to enter long-term production" *

streamliners: **

Ernst Jakob Henne Ernst Jakob Henne ( – ) was a German motorcycle racer and racecar driver. Henne was born in the village of Weiler, near Wangen im Allgäu. His father was a saddlemaker. In 1919 Henne was apprenticed to a become a motor vehicle mechanic. H ...

's BMW RS 500-based streamliner "The Egg", set record in 1937 that stood 14 years; integral supercharger **

NSU Delphin III The NSU Delphin III streamliner motorcycle set the motorcycle land speed record in 1956. Wilhelm Herz rode the machine to at Bonneville Speedway in Utah, to break 200 mph (320 km/h) for the first time. Its Motorcycle fairing, fairing, de ...

, set record in 1956; rotary supercharger ** Lightning Bolt,

Don Vesco Don Vesco (April 8, 1939 – December 16, 2002) was an American businessman and motorcycle racer who held multiple motorcycle land-speed and wheel-driven land speed records. In his lifetime, he set 18 motorcycle and 6 automobile speed records. ...

's streamliner, set record in 1978 that stood 12 years; twin turbo (2×

s) ** BUB Seven streamliner, set speed records in 2006 and 2009; turbo V-4 engine **

Ack Attack The TOP 1 Ack Attack is a specially constructed land-speed record streamliner motorcycle that, , has held the record for world's fastest motorcycle since recording a two-way average speed of on September 25, 2010 in the Cook Motorsports Top Sp ...

, has held speed record since 2013; more than twin turbo (2×

s) ** Castrol Rocket, more than quad turbo (2×

straight-three engine A straight-three engine (also called an inline-triple or inline-three) is a three-cylinder piston engine where cylinders are arranged in a line along a common crankshaft. Less common than straight-four engines, straight-three engines have noneth ...

s) *

Guy Martin Guy Martin (born 4 November 1981) is a British former motorcycle racer and heavy vehicle mechanic who became a television presenter. In July 2017, Martin retired from motorcycle racing. Martin started racing in 1998 and in 2004 competed on a ...

Pikes Peak Hillclimb The Pikes Peak International Hill Climb (PPIHC), also known as The Race to the Clouds, is an annual automobile Hillclimbing, hillclimb to the summit of Pikes Peak in Colorado, USA. The track measures and has over 156 turns, climbing ...

GSX-R 1100 turbo, more than * Neander Motors diesel; / twin turbo parallel twin

turbo-diesel The term turbo-diesel, also written as turbodiesel and turbo diesel, refers to any diesel engine equipped with a turbocharger. As with other engine types, turbocharging a diesel engine can significantly increase its efficiency and power output, ...

Patrik Fürstenhoff "Ghost Rider" is the alias used by a Swedish motorcycle stunt rider, called "probably the most famous flaunter of road rules the world has ever seen", whose internet videos have achieved a "cult following" with millions of views. Biography Ghos ...

's (aka "Ghost Rider")

Guinness World Record ''Guinness World Records'', known from its inception in 1955 until 1999 as ''The Guinness Book of Records'' and in previous United States editions as ''The Guinness Book of World Records'', is a reference book published annually, listing world ...

turbo

Suzuki Hayabusa The Suzuki GSX1300R Hayabusa is a sports motorcycle made by Suzuki since 1999. It immediately won acclaim as the world's List of fastest production motorcycles, fastest production motorcycle, with a top speed of . In 1999, fears of a European re ...

– first documented

wheelie In vehicle acrobatics, a wheelie, or wheelstand, is a vehicle maneuver in which the front wheel or wheels come off the ground due to sufficient torque being applied to the rear wheel or wheels, or rider motion relative to the vehicle. Whe ...

over ; c. inline-four *

Suzuki Recursion The Suzuki Recursion is a turbocharged concept motorcycle shown by Suzuki at the 2013 Tokyo Auto Show. The engine is a 588 cc parallel-twin with intercooled turbo and traction control system. Kevin Cameron described its power delivery in ' ...

concept motorcycle; turbo intercooled straight-twin * Kawasaki's Team 38 racing team using a Ninja H2 at

Bonneville Speedway Bonneville Speedway (also known as the Bonneville Salt Flats Race Track) is an area of the Bonneville Salt Flats northeast of Wendover, Utah, that is marked out for motor sports. It is particularly noted as the venue for numerous land speed recor ...

recorded a 211.621 mph speed on the first pass on August 14 2018 and a return speed of 207.263 mph on August 15 to score a combined average of 209.442 mph. This was a record for the

Southern California Timing Association Southern California Timing Association (SCTA) is a competition sanctioning body that maintains rules and record for Land Speed Racing events held at El Mirage Dry Lake, California and at the Bonneville Salt Flats, Utah. It is a non-profit, volunte ...

(SCTA) P-PB 1000 class for stock under-1,000 cc displacement production supercharged motorcycles.

Notes

References

Books

* * * * * * * * * * *

Periodicals

* * * * * * * * * * * * (Originally published in ''Café Racer'' magazine 'Speed' special issue) * * * * * * * * * * * * * * * *