Engine pulley question

pulley question

hey quick...i went to the part database on here...and was lookin for some pulleys...cause i've heard that some aftermarket pulleys can free up some HPs and torque...anway...i found these...
3 different pulleys

but i'm not sure what each on does...and if its worth the $$...or will it even fit on my '05 S.
does anyone know the difference between a "Tru-Power Pulley Kit - with Alternator Pulley ", "Ultra-A Alternator Pulley", and "Ultra-S Underdrive Crank Pulley"?

help...thanks!

From what i heard, do not get underdrive crank pulley, they do more harm than help your car.

why? what have you heard?

yup, that's what I heard form most of the other car forums.
The underdrive crank pulley is missing something bump something that the stock one has. It will harm the bearing on the engine in long run. Someone used it on his 240SX (or something like that) for about 20-25k mile, the mechanic looked at it and said something like "the engine had a hard life".

Let me try to search that article for you.

================edit================
found it
http://www.ntpog.org/reviews/underdrive/pulley.shtml

It's because aftermarket underdrive pulleys don't have harmonic balancers on them.......but I thought on our cars, it wasn't on the pulley anyway so it didn't matter.

good lookin out wit the link...i'll have to read it...thanks!

so if the pulley comes with that dampin rubber thing (according to the article)...do you thing it would be alright to get one?

^^^ :Nworthy

wow...great info...i guess i'm going with any aftermarket pulley...

thanks!

sorry but i dont feel like beatin this topic to death...but what about the other types of pulleys??

for example: Tru-Power Pulley Kit - with Alternator Pulley ", "Ultra-A Alternator Pulley"

do those pulley do the same thing? cause the same problems? or are they different...cause i saw another corolla with an AEM pulley (i think it was the alternator).

thanks!

The alternator pulley will not ruin technically ruin anything, but your lights may not be as bright, sound system not as loud, etc. but it does provide a little power.

Underdrive pulleys add more power but almost always they come without a harmonic dampener. There are countless threads on newcelica.org of people ruining their engines with these, and yet many people still want them...

It's something to consider if your car isn't your daily driver, and you only use it at the strip...but your still asking for trouble. If you can afford a new engine or rebuild whenver you like...go ahead.