PilotChris

I know this is kinda off topic, but my bro is putting a set of pulley's on his Prelude. One of his friends comes over and tells him not to put the altenator pulley on cause he'll go through batteries every few months (like on his Rx-7) cause it won't be able to charge up if it's underdriven.

He's ordering the AEM pulley set for it and I didn't see any mention of this on their site. Is this something to be concerned about for the Prelude or did AEM take this into account in their design?

Gernby

I don't see how this would be an issue, unless he has a lot of extra accessories (audio amplifiers, fog lights, etc.).

Dinan3XI

Gernby is right, unless he has audio or other little "ice" extras he should be fine. You might feel your windows go down slower and certain things like that may become an issue. But if you stay with a stock sound system and not feed power to extra lighting you should be ok. I know tons of people who have put alternator pullies on their BMWs and they have had no problems. By underdriving the alternator you are opening up a nice amount of power. I would say go for it, just make sure you dont underdrive the crank and its the alternator. I have also heard of people underdriving the water pump, another NONO, i have seen issues with that as well. Just out of curiosity, I am new to the S2K thing(looking to purchase one), how much are the pullies and what are typical gains?

PilotChris

The set my brother's getting is for his '99 Prelude. Their $150.00 for the pair (one for the alternator and one for the powersteering pump). The S2000 doesn't have any pully sets yet (that I know of). They have a "hydro pulley" or water pump pulley, but there's not change in size, only in weight. Supposedly the hydro pulley is 6lbs lighter.

What issues have you heard with the water pump pulleys?

Dinan3XI

I heard this about two BMWs, now this may not have to do with S2000, but i am just speaking from experience I have heard about. The water pumps were underdriven to the point where at intesne driving the car began to overheat. These are incidents I heard about from my mechanic and the other on a car forum.

emc2

No issues known for changing the water pump pulley (only one avail is the same size as stock...no underdrive pulleys are avail). It would be hard for it to be 6lbs lighter though since the stock one weighs 1lbs 2.4 oz

cdelena

IMO there is not much power to be had underdriving the alternator, water pump, and AC clutch.. but there can be problems. Not a worthwhile mod in my book.

Gernby

[QUOTE]Originally posted by PilotChris
[B]The set my brother's getting is for his '99 Prelude.

PilotChris

ohh yeah you're right.. I was thinking something else with the 6lbs. The hydro pulley is 1/3 the weight. The stock pulley is 18.6 oz this one is 6 oz.

I'm not sure it's worth the $130.00 though.