ken02ws6

Managed to find a set of ASP pulleys still in stock but I have to buy the alternator pulley along with the crank pulley. What is the advantage/disadvantage of the alternator pulley since I only wanted the crank pulley in the first place?

Lost Time

It'll just return the alternator back to it's original operating rpm. Some prefer this so you don't underdrive the alternator.

IM LOWR

If I am not mistaken the alternator pulley is the 'race only' set up. Using it slows the rpm of the alternator and may cause charging problems at idle.

IM LOWR

The underdrive crank pulley slows the accessories and if the diameter of the new alternator pulley is larger than stock the alternator will be slowed down making it spin slower than it did from the factory - hence less charging. Your lights may dim a little at idle.

ken02ws6

Not sure if the alternator pulley is an underdrive or an overdrive?
Should I still get this kit or should I stay away from the alternator pulley. Car will never see a high power stereo or anything like that.


Thanks for the info

ken02ws6

Anybody else?

xaon

iTrader: (12)

There are two different Alternator pulleys that I have seen. An overdrive to return the alternator back to stock spinning speed, and an underdrive to reduce some more additional drag. Proper charge speeds with JUST the crank pulley is like 650rpm, with the underdrive alternator pulley it's 800 or 850.

If the package contains the belts, I would go ahead and order it and install both pulleys and use the supplied belts for it. If it doesn't include the belts, I would just buy the kit and not install the alternator pulley, then just buy the proper belt for just the crank pulley. You may be able to sell the alternator pulley after the fact and recoop some of the cost of it. (They're really not that expensive though, ~23 bucks) (You can find a break down on the different parts at http://www.thunderracing.com/index.c...ategoryid=1079 )

Hope that helps.

ken02ws6

Thanks for the help guys. Guess from the sound of things that the alternator pulley may not be so bad and since its only $20 I can scrap it if I want too.

2001CamaroGuy

iTrader: (6)

overdrive alternator pulley....GOOOOOOD..get it <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

underdrive alternator pulley......BADDDDD.....stay away from that <img border="0" alt="[punch]" title="" src="graemlins/gr_punch.gif" />


It’s best to keep the alternator spinning at the factory speed in order to prevent battery drain. You will loose "some" (very little) HP by speeding the alternator back up but the real gains in HP are coming from the crank pulley its self (reduction in rotating mass), and slowing down the AC, the water pump, and the power steering so the sacrifice is minimal.

Chris

ken02ws6

What to do? What to do?

anybody else?

eallanboggs

iTrader: (1)

How much time do you spend at idle speed? That should be the determining factor. If you do normal driving you probably don't need the OVERDRIVE pulley unless you have a 1000 watt stero system. Once your above idle speed the UNDERDRIVE pulley will fully charge your system. When you reach the point where your up to 14VDC spinning the alt any faster just wears out the alt bearings because you've already reached the full charge limit. That's when the voltage regulators take over. This means that anytime you spin and alt over 2K RPM your overdriving the alt and spinning the alt bearings faster than they need to be. The alt puts very little load on the crank pulley compared to the water pump.

ken02ws6

The pulley is an underdrive and I have decided that I am going to give it a try. Guess I'll take it off and sell it to one of you guys if I don't like it! LOL

Thanks for the help

viper killer

hi i have a 98 camaro .

am buying a crank pulley shold i buy a overdrive alternator pulley or underdrive alternator pulley
with it or insallin the crank pulley alone well be ok ?

whatever

A4=overdrive pulley
M6=underdrive won't gain you any noticeable difference but probably won't hurt anything as long as you stay away from after market stereo.

Larry

iTrader: (4)

I have the underdrive crank and aluminum alternator pulleys on my 98 automatic. I have had them almost since the car was new. It does discharge at idle if below about 900 rpm but doesn't hurt a thing as long as you don't idle for prolonged periods of time with the ac on. Of course I have a loose converter and set my idle about 900 rpm normally so I get full charge at idle. I have adjusted the idle lower with it discharging at idle and still no problems with the battery going dead. I do put the tranny in neutral and idle it up slightly when in heavy traffic. I still have the original factory battery.

Be sure to order the aluminum alternator pulley if you get the underdrive alternator pulley. It will save weight and ASP hard coats all aluminum pulleys for longevity.

ken02ws6

ttt