MaxedOutSS99

I pretty much don't know anything about pulleys . What is the difference between underdrive and overdrive? wich is best. what do i need to get when buying one, such as bolts and a new belt obviously, anything else? if there is a thread about this already can somebody point me to it, thanks.

Judd

iTrader: (1)

If you are looking to gain HP or make your car faster, you want a underdrive pulley. Try a search on it.

BergerMan

The underdrive pulley is installed on the crankshaft and reduces the amount of power required to run the accessories by reducing their rpm. One of the drawbacks of reduced accessory rpm is lack of alternator charging on cars with high powered stereos. This is where the overdrive alternator pulley comes into play. It will increase the rpm of the alternator and retain the stock charging capabilityof. Even if you have a mild stereo there is no need for the alternator overdrive pulley.

ChazLS12002

I would personally, save up a little more money and get a Torque Converter. The pulleys won't add but 10 hp for $300 and the TC will liven up your A4

Fast SS on TNT

iTrader: (1)

See my sig....no pulley listed there. Its a waste of money me thinks!

ApacheDrill

iTrader: (21)

Not trying to Hijack the post.. but with all that said. Where does the harmonic balancer come into play?

MaxedOutSS99

thanks a lot guys, yea i think ill just save the money and buy a torque converter.

Raben

iTrader: (5)

I'd actually do both.

I did the TC first though. . .went with a TCI 3500 stall and so far I'm pleased with it. I'm fixing to install a ASP underdrive pulley though. See what it does for the car down the track. Not worried about the dyno numbers but moreso if it actually will shave off 1 tenth of a second off my times

WJ SOM SS

iTrader: (11)

ASP underdrive pulley is a good mod, It's usually always good for .1 second at the track. I've had a '99 M6 SS, and now a '02 A4 SS. ASP underdrives on both, .1 second in the 1/4 mile with both. It's a good quality piece, that's worth doing, in my opinion. But, on a A4 car, the stall converter is the best bang for the buck...but way more money than the underdrive pulley...Best wishes. WJ.