Underdrive Power Pullys
Underdrive Power Pullys
Senior User
Joined: Oct 2002
Posts: 244
Likes: 0
Under drive pulleys change the ratio that the engine spins the alt,pwr-str,air pump,a/c.By changing crank pulley size and other pulley sizes it reduces the amount of parasitic h.p. loss and effectively gives you a power increase by freeing up the engine.The down side is that your charging system will not be operating at its peek ,so depending what you use the vehicle for you may want to weigh the trade off of power vs. usage.I would say that the most power gained from this would be in the higher rpm range(probably why this has been popular with the mustang guys).
Tuned
Joined: Dec 2002
Posts: 305
Likes: 20
From: North Padre Island, TX
Have seen a few dynos before and after underdrive pulleys. Minimum gain. Maybe 2 to 4 hp. Not a big increase for the cost. And again, mainly at higher rpms. More effective in a sprotscar than a superduty.
