ChrisRZ28

This is just an FYI for A4 guys who might be looking for info on 25% underdrive pulleys and overdrive alt pulleys and belt sizes. I've got a '01 Z28 that I had put an underdrive pulley on. As most of you know, sometimes you get dimming headlights, slow turn signals and dead batteries. The dimming headlights and slow turn signals (I killed the battery once) drove me crazy when I'd drive at night. Went searching this forum and found some info and bought an overdrive alt. pulley and a new belt. A K060755 belt was recommended. Just got done putting the overdrive pulley on. I had to take the alt. off the car to do this job. You will need a 24mm 1/2" drive socket and 1/2" drive electric impact wrench. Used my old belt with some c-clamp vise-grips to hold the pulley still and loosen the nut. The new pulley is smaller then the stocker so you can't use a impact socket on it because the wall of the socket is to thick. Non-impact socket is what you want. Put everything back together but I don't have my new belt yet. So I thought wtf, I'll try my shorter belt that is already on the car which is a K060760. Well, the damn thing fits! Being the new alt. pulley is smaller then the stocker, the belt actually fit a little better then before. So it looks like I will have a spare belt when that gets here. Went for a test drive and no more dimming headlights, no more slow turn signals and the needle on the voltmeter stays still at about 14. Now I'll be happy when I drive this thing at night.

s25hanh

iTrader: (8)

so you put an underdrive pulley on then you started seeing those symptoms? i have low alt. current as is so im wondering if this would help. did you notice any performance with the underdrive and overdrive pulley?

Mike Morris

iTrader: (55)

Been running one(Powerbond-SLP) for a long time and no issues here????

2fresh

iTrader: (20)

yea did the same here, eventually had to replace the alt though to fix it completely and a new battery as well.

ChrisRZ28

Can't really say I saw any performance. Maybe the engine revs a little quicker. But yeah, I didn't have any symptoms until after the underdrive pulley install. As far as the low alt. current, does your gauge needle drop when you come to a stop? Mine did and would then return to normal when I started driving again. After the alt. pulley install my needle doesn't move at all when I come to a stop while still in drive.

ChrisRZ28

Do you have an A4 or a M6? From researching the forum it seems autos idle lower in gear at a stop sign so you get dimming lights and such.

Wimimc

iTrader: (2)

i've been debating about whether i should get the alt pulley as well when i get the crank pulley. Now i'm fairly certain i will. Where did you get the alt pulley from?

ChrisRZ28

I don't think I messed up my alt., but I don't daily drive my car right now. I did have to recharge the battery one time before I installed the alt. pulley so hopefully I didn't do any damage to the battery or alt.

ChrisRZ28

Texas Speed and Performance.

ChrisRZ28

Keep in mind I just put this alt. pulley on last night so this has not been a long term thing. But not having the dimming lights and other symptoms after the install is a good sign.

shepss217

iTrader: (5)

yeah maybe it's just me but it sounds like you wasted your time and money, if you underdrive 1 pulley and overdrive another aren't you defeating the purpose of an underdrive pulley to begin with?

ChrisRZ28

I read somewhere on this forum that the overdriven alt. doesn't effect the underdriven crank pulley. The underdrive pulley helps with the drag of the waterpump and powersteering pump...or something like that. As far as proving it...I really can't. Waste of money...probably. I've read elsewhere that most people can't really feel any difference other then a quicker revving engine. I don't mind spending some money on some simple bolt-ons. These cars have enough power stock to get in trouble on the street, and plus, I live in smog **** la-la land of Calif. so I don't feel like (lazy) changing stuff (headers, cam, intake etc.) to smog my car every couple years. I'm just dreaming here, but if I had the money, I would love to put a bone-stock LS7 in my Camaro...all that power and pass any smog test...

s25hanh

iTrader: (8)

well my volts are like 13 constant. i wish it was like 14 constant. i have subs and i am hoping it wont make my lights flicker

ChrisRZ28

I still have the stock radio in my car. My lights used to flicker but a couple years ago I replaced my alt. (note related to my underdrive pulley) and haven't noticed it since. But I don't know if that alt. was what 'fixed' it.

Sommer86

iTrader: (46)

This is EXACTLY what my car has been doing for the last 2 years. I hope I can hit 14... I hover around 13 driving, or closer to 13.5.

I've had my OD pulley for a year and it STILL isn't on my car, lol. I'll do it ASAP!

ChrisRZ28

Better get to it! It's alot nicer to drive at night knowing things work like there suppose to. Whats funny is the actual pulley swap is a piece of cake. It takes longer to get the alt. off the car...

01ssreda4

iTrader: (96)

Why the obsession with hitting 14?

Sommer86

iTrader: (46)

Not an obsession, just want to but on the "other side" of 13....just in case

Any tips for the R&R? (with the alt. still in the car)

01ssreda4

iTrader: (96)

Anything over 12.6 is charging. No need to be in the 14s.

Sommer86

iTrader: (46)

Even better!