Any muffler with a wider exhaust port that allows for a louder sound. Typically found on cars owned by drivers who can't afford a real street-racing car but want to act like they have one.
An exhaust found on a typically shitty car owned by chavs, such as a Corsa B or a 2004 A3. They make a horrendous sound and make the driver look like a complete idiot.
Jon: Listen to the sound of this bad boy, just stuck it on my new Corsa B
Dom: That's fucking class that g, everybody is gonna be well jealous init
Dave: That fartcan sounds shite
Oversize "performance" exhaust found on underpowered import "rice" cars. Generally reduces performance and makes the car sound like it's farting, or like a lawnmower.
Fartcore is not to be confused with Deathfart. Fartcore still retains the underlying melody of flatulence. There's more oxygen and hydrogen. Deathfart is all about the rhythm of sulphur.
Gustav switched from a life of Taco Libre and Deathfart to Sibylla and Fartcore, and we are all breathing easier.