Underdrive pulleys...

[Xeiros]

Am I safe to assume that if I were to put on an AEM underdrive alternater pulley, and an Unorthadox Underdrive crank pulley, that I'd have to purchase a HO alternater to keep my stuff running smoothly?

I should be safe if I put either of the pulleys on now, as long as I don't put both on right?

Also with the crank pulley, and I going to have to have a case relearn done, and if so, about how much do those run?

[hayabusa]

i don't know if you can change the alt pully. But i hear thee ffd performance pully doesn't mess with anything. Hay if your in bloomington look me up

[Xeiros]

Yeah, the AEM pulley is for the alternater. And likewise if you're ever in the Quad Cities area.

http://images.cardomain.com/member_images/5/web/413000-413999/413115_14_full.jpg

[hayabusa]

wonder if you have to get a differnt belt with that

[Xeiros]

I'm almost certain that you do, but I think it comes with the pulley.

[Nacho]

as far as the underdrive crank pulley you dont need to buy a ho alternator the voltage difference between the stock pulley and underdrive one from FFP is 0.1volt so you wont even notice, plus the gains are pretty decent. the alternator underdrive pulley im not sure of but i doubt you will see any gains, however both pulleys will require a shorter belt.

[Xeiros]

What about the case relearn?

[Nacho]

the CASE relearn isnt absolutely necessary but it probably wouldnt hurt some people have had to do one some havent, i would just to be sure.

[VanishingImage]

If you have a big system then I suggest getting a HO alternator,if not then you don't have much to worry about,just make sure your charging system is in good shape or like new before doing it.

If you do BOTH pullies you might see a little gain,which is better than none. Few people have noticed quicker revs and acceleration but no real gain in 1/4 mile times

[RocketMan]

I noticed the diff...but it came at the price of my timing being all screwed up. I still endorse the mod though. Just be careful.

BTW the alt uses rectifying diodes to drop the voltage from something like 70 volts so i don't even believe in the 0.1 Volt thing at all. I think its measurement error. All it does is draw less power, so more of the alt's magnetic material is saturated to produce the voltage demand.

[c3hp0]

You can increase the voltage using a rectifier diode on the voltage reference wire - see ZZP's description of how do it at zzperformance.com (http://www.zzperformance.com/grand_prix/articles1.php?id=48)

Watch out how many of those you install, since getting close to 15 volts can make many of the electronics in your car very unhappy, especially over the long run.

In case you noticed that the tech article is in the Grand Prix section, they sell a plug in module for both the W-bodies and the N-bodies.

You can pick up an underdrive (slightly larger) pulley from a W-body alternator, so don't both spending extra cash on that one, unless you really have to have one made from machined aluminum. I bought two of them from an alt rebuilding shop locally for $10 CAD each (they pulled them off of some alts they had laying around and sandblasted and painted them for that price).

I posted a while ago about the exact size differences b/w the n-body and w-body alts, if you really need to know the difference.

[Matt95GT]

Originally posted by Xeiros
What about the case relearn?

Doesn't apply... there's no crank sensor on the pulley like 3400's.

[VanishingImage]

Its been seen that with the ALT UDP your charging light will come on,might be dim. You are getting a lesser of a charge. Those voltage boosters from ZZ Performance are probably worth using. Haven't heard of anyone with them yet but in theory they sound good

[c3hp0]

Just installed a 1amp diode on the Alero on Sunday after an oil change and it works just fine. Picked up about 1/2 volt pretty much across the rev range - from a scan.

Took about 20 minutes from start to finish - use the orange voltage reference wire and follow ZZP's directions.