Hi
I was just reading about a underdive pulley and have read that its a good mod in terms of cost and performance increase and would like to get one for my first mod. but would like to know some things about it first:
1) where is this pulley located? (im getting my cambelt changed soon, would it be a good time to put it on then)
2) what would be the actual performance increases on a gt4?
3) does the pulley just need to be fitted on? (does it need any balancing or exact fitting/measuring)
4) what are the negative effects and things to look out for from it?
5) any one that you would recommend?
6) should i replace any other pullies at the same time?

thanks for any help, its much appreciated

This post has been edited by beno: May 15, 2006 - 2:22 AM

It depends on the undriven pully kits. Some kits come with more then one pully such as a larger alternator pully and a smaller crank pully.
But the basic underdriven pully kit will change just the crankshaft pully on the front of the engine.( The large pulley that all the belts connect to.)

Yes it would be a good time to switch to a under driven kit when you are changing the cam belts.

Sorry I do not know how much hp the under driven pulleys will free up. The kit does not increase hp, but prevents other accessories from taking power away.

The side affects of an underdriven kit is it will run your accessories less. meaning, if you drive your car on shorts trips you may not charge the engine battery enough; resulting in a dead battery. The under driven pulley kit may not spin you AC unit fast enough making air conditions less cool in the lower rpm such as during idel.

Typically a under driven pulley kit does not need balancing, they should already come balanced.

hope this helps.