A type of high-flow muffler consisting of a perforated inner tube surrounded by tightly packed fiberglass inside a steel outer shell. Exhaust gases flow straight through with minimal restriction, while the fiberglass absorbs high-frequency sound waves. They are known for producing a loud, raspy exhaust note.
Heard on the job
He chopped off the factory silencers and welded in a pair of glasspacks to wake up the V8.
Also heard as
- cherry bomb
Related terms
Muffler
An acoustic chamber in the exhaust system designed to reduce the noise generated by combustion.
Exhaust system
The piping and components that route spent combustion gases away from the engine.
Straight-pipe
To remove a vehicle's mufflers and catalytic converters, replacing them with empty tubing.