Glasspack
Encyclopedia
A glasspack, sometimes called Cherrybomb (a genericized trademark
of a popular brand of glasspack) is a type of automobile muffler
in which the exhaust gas
passes straight through the center of the muffler. Packed fibreglass surrounds the exhaust channel and absorbs some of the high-frequency sound.
All mufflers impede the flow of exhaust gas and create back pressure
on the engine. Muffler designs involve trade-offs between noise, back pressure, weight and cost. Replacing the factory muffler with one that creates less back pressure is a modification that is often made by hobbyists interested in increasing the engine power of their cars.
Glasspacks are an old, simple, and relatively inexpensive design. They are very effective at reducing back pressure, but not very effective at muffling noise. Thus, they preserve more of the engine's power while sounding louder than conventional mufflers.
Some modern muffler designs are similar in principle to the glasspack, but use more sophisticated sound-absorbing materials such as stainless steel
mesh, and more advanced acoustical engineering, reducing noise while retaining the power-preserving advantages of a straight-through exhaust flow.
Genericized trademark
A genericized trademark is a trademark or brand name that has become the colloquial or generic description for, or synonymous with, a general class of product or service, rather than as an indicator of source or affiliation as intended by the trademark's holder...
of a popular brand of glasspack) is a type of automobile muffler
Muffler
A muffler is a device for reducing the amount of noise emitted by the exhaust of an internal combustion engine. A US Patent for an Exhaust muffler for engines was granted to Milton and Marshall Reeves in 1897....
in which the exhaust gas
Exhaust gas
Exhaust gas or flue gas is emitted as a result of the combustion of fuels such as natural gas, gasoline/petrol, diesel fuel, fuel oil or coal. According to the type of engine, it is discharged into the atmosphere through an exhaust pipe, flue gas stack or propelling nozzle.It often disperses...
passes straight through the center of the muffler. Packed fibreglass surrounds the exhaust channel and absorbs some of the high-frequency sound.
All mufflers impede the flow of exhaust gas and create back pressure
Back pressure
Back pressure refers to the resistance to a moving fluid by obstructions or tight bends in the confinement vessel along which it is moving, such as piping or air vents, against its direction of flow....
on the engine. Muffler designs involve trade-offs between noise, back pressure, weight and cost. Replacing the factory muffler with one that creates less back pressure is a modification that is often made by hobbyists interested in increasing the engine power of their cars.
Glasspacks are an old, simple, and relatively inexpensive design. They are very effective at reducing back pressure, but not very effective at muffling noise. Thus, they preserve more of the engine's power while sounding louder than conventional mufflers.
Some modern muffler designs are similar in principle to the glasspack, but use more sophisticated sound-absorbing materials such as stainless steel
Stainless steel
In metallurgy, stainless steel, also known as inox steel or inox from French "inoxydable", is defined as a steel alloy with a minimum of 10.5 or 11% chromium content by mass....
mesh, and more advanced acoustical engineering, reducing noise while retaining the power-preserving advantages of a straight-through exhaust flow.
See also
- Aftermarket exhaust partsAftermarket exhaust partsAftermarket exhaust parts are intended to replace the factory fitted exhaust components of a car, motorcycle, or other motor vehicle in order to improve the performance, visual appeal, or sound of the vehicle. Generally, performance enhancements are achieved by reducing the back pressure of the...
- Exhaust systemExhaust systemAn exhaust system is usually tubing used to guide reaction exhaust gases away from a controlled combustion inside an engine or stove. The entire system conveys burnt gases from the engine and includes one or more exhaust pipes...
- Modified carModified carFor the American oval track automobile racing series, see Modified racingThe term modified car is given to any vehicle that has been altered from its original state; most commonly with aftermarket components...
- Boy racerBoy racerBoy racers refer to people, usually males in their late teens or early twenties, who "cruise" around in vehicles modified with loud exhausts and stereos, or modified body kits. This behavior is frowned upon by members of the public irritated by the noise and the criminal behavior associated with...