Glasspack

From Wikipedia, the free encyclopedia

A glasspack, sometimes called cherry bomb (a popular brand of glasspack), is a kind of automobile muffler in which the exhaust gas passes straight through the center of the muffler. Packed fiberglass 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, which reduces power. Muffler designs involve tradeoffs between noise, back pressure, 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 not only make the engine more powerful, they make it sound more powerful.

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.