underdrive pulley question, info help please Options

[beno]

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