ScreaminRedZ

iTrader: (3)

I keep seeing people making decent gains (8-10 whp) with underdrive crank pulleys. I'd like to buy one but was wondering if I should also get the overdrive alternator pulley to keep my battery charged?

Thanks

Cstick

I would leave the stock pulley on. I have the overdrive alt pulley and it acts fine with no electrical loads on it at idle. But I have to keep the rpm above 1000 to charge above 13V when the a/c is on, and head lights are on. Not a big deal, and it is not going to drain your battery while you sit at a stop light. If I did it over again I would go underdrive alt or just stock alt. I think the ASP web site says what RPM will charge like normal, with each set up.

Lithium

iTrader: (47)

Overdrive for a system only.

jlrz28

iTrader: (7)

I have a MTI underdrive pulley, havent had any problems with it.

BudH

iTrader: (3)

I'm running the ASP Underdrive crank and alternator pulleys (4 years) on my 6 speed with no problems. But, I don't sit for extended periods in traffic.

BackinBlack02SS

iTrader: (7)

The stock idle for an M6 car is 800rpm. The stock idle for an A4 car is 550rpm. They both have the same alternator. The majority of underdrive pulleys/dampers slow down the accessories by 25%. Do the math, you will be fine.

Red99TA

iTrader: (11)

I notice the headlights flicker when below 1200 rpms but that's the only issue I have w/ it (just the ASP UD crank pulley and stock alternator pulley).

Kyle C

SLP U/D and stock alternator pulley with no problems.

Big Ty

asp 25%, no alt pulley. everything is working fine.

Brandon35thSS

i have the slp ud crank pulley and have no problems

ScreaminRedZ

iTrader: (3)

Thanks alot guys! I wasn't going to get one but after I keep seeing people making making decent power gains with them I just can't pass it up.

Tiger2o69

iTrader: (16)

If anyone wants to buy an underdrive alt. pulley I have one for sale. thanks.