American Cycle Performance is plain and simple all about performance. An exhaust system is a very important part of the equation. Exhaust System choices for a Harley Davidson an almost endless. Drag Pipes, 2 into 1, True Duals and Slip-Ons are most common. There is a huge difference in what looks cool and performs effectively. Some customers only care about sound. At ACP we DO NOT TUNE FOR SOUND!
Here is a little exhaust system information. The 3 major factors that affect the performance of an exhaust system are Exhaust Gas Velocity, Sonic and Thermal Pulse.
The Exhaust Gas Velocity is the rate at which the gas travels. The optimum rate is 5 feet per second.
The sonic pulse, sonic meaning sound, like a shock wave. This sound pulse travels through the exhaust and at the end of the pipe turns around and heads back towards the exhaust valve. Under certain conditions this can even push air fuel mixture back through the intake. Common with shorter drag pipes.
The Thermal Pulse, thermal meaning temperature, is created by hot gas exiting the exhaust valve from the combustion chamber also reverses direction at the end of the exhaust pipe but at a different rate then the sonic pulse.
Exhaust System tuning is vital to jetting a carburetor as the exhaust affects how the carburetor scavenges and atomizes fuel.
American Cycle Performance will be to recommend an exhaust system that meets or exceeds the expectations of your application. Whether you are looking for mid range torque, high end horse power, have a stock engine or large cubic inches.
Exhaust System Tuning
American Cycle Performance is able to tune MOST exhaust systems by adding or subtracting back pressure. Sometimes if an exhaust system is to far out of range jetting the carburetor correctly will be impossible.
After installing a new exhaust system keep in mind if carbureted it must be rejetted and if Fuel Injected it will require remapping to compensate for changes in how the engine is breathing.