[Arnold K.]

Exhaust is not unsprung. But be honest, did you really search? LOL. It's the first link on Google.

"Unsprung weight includes the mass of components such as the wheel axles, wheel bearings, wheel hubs, tires, and a portion of the weight of driveshafts, springs, shock absorbers, and suspension links. Even if the vehicle's brakes are mounted outboard (i.e., within the wheel), their weight is still considered part of the unsprung weight."