Suitable for A1 licence Suitable for A2 licence BMW Motorrad Approved Used Bikes HONDA CBF1000 Bikes for Sale << First 1 2 3 4 Last >> A velocity stack, or air horn,[1] is a trumpet-shaped device of differing lengths which is fitted to the air entry of an engine's intake system, carburetor or fuel injection. It is designed to: Modern engines universally have tuned intake tract volumes and associated resonance frequencies, designed to provide higher than atmospheric intake air pressure while the intake valves are open - increasing the density of the trapped air in the combustion chamber (higher compression).[] Modified engines often have the original air box and associated ducting removed and velocity stacks are installed as accessories. Modern fuel injection systems with a plenum and single air inlet typically incorporate some sort of radiused entrance, designed to improve power, based on air flow increases. Power gains are usually at higher rpm.

In amateur and professional racing, aftermarket velocity stacks are often used, as rules allow, and gains in the order of 2% to 4% can be obtained when inlet radii and stack lengths are optimized for that engine. OEM automotive manufacturers have many regulations to adhere to. One of these is noise. A properly tuned intake tract produces a rather audible intake noise under high airflow conditions - that is commonly "untuned" to allow the vehicle to pass EPA and DOT noise regulations. The length of the stack is known to have a direct effect on a particular engine's boosted power range. Most current aftermarket stacks are designed to be run "in" the airbox and a company[] that does research well will have some applications that have all the same length and some applications that have differing lengths of stacks on different cylinders. It is commonly related that "stand off" (air–fuel mix that gets pushed back out of the port, usually at full throttle / low rpm) is somehow captured by installing a longer intake pipe (stack)[].

but, it is actually that the intake valve is closing too late and the combustion chamber is simply overfilling and blowing back out the intake port, before the intake valve closes.[] A longer inlet pipe will create a later intake pressure wave that will help keep the air in the chamber until the intake valve closes. The acceleration of air flow into a duct is inherently a highly efficient process and the difference between even the crudest radius inlet, and the most aerodynamic shape possible is slight, amounting to no more than a few percent.[] The flow coefficient of a perfect entry would be 1.0 while the coefficient for a sharp edged entry would be 0.6 and a re-entrant plain pipe 0.5.[4] In practice these latter types of entry are never used for engine intakes. There is always some attempt to provide some radius at the entry. This means that total engine airflow would not increase by the amount suggested by these figures, which apply only to the entry alone, as the inlet end is never the smallest or most restrictive part of the system.

Because the greatest losses to flow occur near the valve seat, actual overall gain from any improvement of the entry flow would be much less. In the real world, on high-rpm IR IC engine, using a minimum amount of inlet radius gives the best wave strength and a power boost of 2% to 4% over a 3000 to 3500 rpm range. Reem Acra Wedding Dress SydneyUsing a larger radius, like 3/4", broadens out the resonant pressure wave rpm range, but the compression boosting pressure wave is greatly diminished and almost unnoticed by the engine. Headlight Bulb For 2008 Honda RidgelineThe term air horn is sometimes used for velocity stacks;Friedrich Electronic Air Cleaner Manual[1] it is unrelated to the noise maker or signalling air horn.

Stuart Hilborn, inventor of fuel injection systems that popularized the use of velocity stacks for high-performance car engines.XJ600S - Seca II Parts XJ600S - Seca II Parts XJ650L - Seca Turbo Parts XJ700X - Maxim X Parts XJ750M - Midnight Maxim Parts XS1100L - Midnight Special Parts XS850L - Midnight Special Parts XT1200 Super Tenere ES Parts YZFR1LE - R1 Limited Edition Parts Being the Best In 1953, Yamaha, under the guidance of Genichi Kawakami, Yamaha Motor's first president, began a trial manufacture of motorcycle engines. Venturing a little late into the motorcycle world, Kawakami said, "If you are going to make it, make it the very best there is." In August 1954, the YA-1, Yamaha's first motorcycle was finished and immediately put through a 10,000 km endurance ride. It passed and Yamaha was a force to be reckoned. In 1958, Yamaha was the first Japanese maker to compete in international racing, finishing a respectable 6th in the Catalina Grand Prix race.

The DT-1, considered Yamaha's first off-road motorcycle debuted in 1968 and put the company squarely on the map for on/off-road motorcycles in the United States. The company manufactured its 20 millionth bike in 1982. In 1994, Yamaha created Star Motorcycles, the brand name for its cruiser series of motorcycles. Today, the Yamaha bike line includes sport bikes, trail bikes, road racers, dual-sport, sport touring and motocross style bikes. The company manufactures 50 to 500 cc scooters and their range of motorcycles is 50 to 1,900 cc. Yamaha's success is well-known. The Yamaha YZ450F took the Supercross Championship in 2008 and 2009, and the company boasts 36 World Championships including three in MotoGP, nine in the 500 cc two-stroke class and one in the World Superbike Championship. Kawakami's motto to be the best certainly applies to every facet of the motorcycle. If the whole is equal to the sum of its parts then it makes sense that every Yamaha part is made to be the very best. You can't make the best motorcycles if you don't have the best parts.

There is no denying Yamaha Motor Corporation's award winning and race dominating motorcycles. Our customers who ride Yamaha number in the thousands and we understand Yamaha parts are highly sought after. Who wouldn't want Yamaha parts considering the company's winning reputation? Kawakami also said he believed the most important considering point in building a product is to keep in mind the people who use it. MotoSport owns that belief and we address the demand for Yamaha parts by customers who keep their bike 100 percent Yamaha and use only Yamaha factory parts. Others who like the customization route to improve power, performance, looks and/or style we suggest starting with the most popular and easiest upgrade, exhaust. Our stock of exhaust systems for Yamaha motorcycles come from top brands such as Two Brothers,Leo Vince, Yamaha GYTR and more. When improving your Yamaha motorcycles power, check out our selection of velocity stacks that improve intake and throttle response. Adding new power from exhaust and intake should be controlled by a fuel management system to correctly balance the fuel and air mixture for optimum power and performance.