We show how to install a Trick Flow Specialties underdrive crank damper on a 2006 Dodge Charger Hemi, then dyno test it for 8 more HP.

GTR High Performance’s co-owner and lead technician, Ricardo Topete, tightens down an underdrive crank pulley on the push-rod 5.0 engine in Max Partida’s Fox ’Stang.

Underdrive pulleys are similar to throttle bodies, cold-air kits, and performance chips in that the parts are easily installed with simple hand tools.