do it now, its the smartest upgrade you can do, also a tip for anyone with an older car, if you have a old car that has its radiator fan run by a belt change it with an electric you'll gain 6-10 HP and torque and your engine will love you.
I wouldn't exactly say it's worthless. It's just a way of gaining a little more horsepower, like an intake or exhaust. I know Neuspeed has a great reputation, but if you know someone who's had it on their car for a while, ask them if they've had any problems caused by it. If the pulley isn't balanced exactly right, it will vibrate and put too much strain on your engine.
i heard something about that the stock pulley moves fast enough, and if you put the after market pulley it would strain the engine because it will be moving faster than it should......most people dont have it on there fsi engines....i would say it's pretty unnecessary because if a good tuning shop like i mentioned before does not want to install it, i would say it's not worth it/...
Actually, the power pulley does put less strain on the engine, because a) it's smaller and lighter, hence, easier to turn and b) it's smaller so causes the accessories it drives to turn slower; again easier on the engine. As for the manufacturing quality and balancing issues-I don't have one, and won't, but someone out there does. Can anyone with miles on their pulley add anything?
And about the warranty; this is another mod that can give your service department pretty much carte blanche to void a wide range of coverage: Engine (because of questionable balancing), electrical (fried DC power regulator and such), A/C (low compression at idle). Not sure what else is driven by that pulley, but you get the idea.
I will never do power pulley "upgrades"! I used to have a modded out civic and I decided one day to put AEM power pulleys in just for the heck of it cuz I had every mod under the sun already in it. BAD IDEA! My ride could not hold an idle and would cut off on me. It was sucha pain in the butt!!!!