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Underdrive Pulley

Posted: Sun Jul 06, 2003 9:29 pm
by St. Martin
Has anyone installed an aluminum underdrive pulley to their Vibe? if so, what are the gains, how much, how long did it take, yadda yadda

Re: Underdrive Pulley (St. Martin)

Posted: Mon Jul 07, 2003 12:28 am
by Bocaj77
I have the Unorthodox Racing one on mine. I did notice a little better acceleration but nothing major.

Re: Underdrive Pulley (St. Martin)

Posted: Thu Jul 10, 2003 10:53 pm
by tau166
AEM makes a Tru-Power pulley system, but I don't know anyone who has put it on yet.

Re: Underdrive Pulley (silverawd26)

Posted: Sun Jul 13, 2003 10:36 am
by dmitri
no i dont think that caused his i think its very unprobable. The way an underdrive pulley works is by underdriving the devices, but all of them are underdriven very little, not enough to damage them, especially something like an oil pump. Most of the power gained is because they are alot lighter then stock, especially the cran pulley. I'd get them but i want alot of power for my altenator since i have a powerful head unit and amp. and i dont have the cash for it

Re: Underdrive Pulley (dmitri)

Posted: Sun Jul 13, 2003 10:46 am
by millster
quote:no i dont think that caused his i think its very unprobable. The way an underdrive pulley works is by underdriving the devices, but all of them are underdriven very little, not enough to damage them, especially something like an oil pump. Most of the power gained is because they are alot lighter then stock, especially the cran pulley. I'd get them but i want alot of power for my altenator since i have a powerful head unit and amp. and i dont have the cash for it Actually, the pulley's only effect on the oil pump is potential vibration. If I'm not mistaken, the pump is driven off the crankshaft, not the crank pulley. The issue with oil pump failure and underdrive pulleys is if the pulley is improperly installed. The major killer is lack of a harmonic balancer. If the pulley isn't balanced, the crank will "wobble" in its seat and eventually chew the bearings, seals and anything directly attached to pieces.I've personally seen engines with such damage at rather low mileage that all had one thing in common. Cheap aftermarket crank pulleys. Supposedly Unorthodox has a lower trouble rate than some others, but I'm still not convinced they're safe.

Re: Underdrive Pulley (silverawd26)

Posted: Sun Jul 13, 2003 1:35 pm
by dmitri
lol different then on my malibu, i havnt really looked at the vibes oil pump just assumed. You shouldnt worry, just do it right silverawd

Posted: Fri Feb 27, 2004 2:29 am
by cibomatto
Bump.. any additional feedback on this? I am curious about this

Re: Underdrive Pulley (tau166)

Posted: Fri Feb 27, 2004 9:18 am
by engine1
The AEM kit is just an alternator pulley and a belt. No other pulleys. JET performance has a pulley kit avail. but I don'y kmow what it comes with.