My car is bassically stock, would it hurt anything or would i have to change anything else if i upgraded the underdrive pulley???

 

You can put an underdrive on a stock car and gain some HP. It is not gonna hurt anything. You are also not gonna feel any change in HP, its only gonna free up 1-2HP.

 

Depends on what style you get. If you go with the "street" version that allows you to keep power steering and a/c, you'll see a good 5 HP. If you get the "race" version that runs the alternator only, 10 HP is pretty standard. The UDP isn't as dependant on other mods to see gains since it's a straight reduction in rotational mass. Same as going to lighter wheels.

Best of luck!

 

awesome, thanks guys, i'll look into that