underdrive pulleys question

I am thinking about getting the steeda underdrive pulleys because i have heard alot of people are happy with getting the pulleys.I was wondering if there is any way they can hurt the motor and if it affects it in any negative ways?
 
no hurt on the engine. it just under drives your accessories. i am more into the lightened pulleys than under drives. you normally lose like 25% of your power that powers your car stuff. if you have a full audio system in your car, it could be affected. if you have stock stereo stuff, it is no big deal.
 
you should be fine. It's about an hour and a half install yourself. Just make sure you have a harmonic puller and go ahead and bake/boil the new crank pulley so it expands and is easier to put on. Just make sure you remember how the belt goes back on.
 
I'm running a 1.1k watt amp with Steedas, no headlight dimming even with bass before I bought my capacitor (did that just to be safe). I'm sure maybe the A/C is affected a bit, but it still works when I use it (which is like 1-2 times a year).