Mega small underdrive pullies??

[LT1Killa]

My 89 Gt has underdrive pullies. (like most do) However, my crank pulley is only like the diameter of a pop can. I've seen under the hoods of many stangs and never seen these pullies before.

How many of you have seen these super underdrive pullies before? I figure they must be a nice power boost over regular underdrives.

 

[mike93lx]

you have to take into consideration the sizes of the other pullies. if they are bigger than normal, you could still have underdrive pullies. but if they are all similar to most kits, and you have a crank pulley that small, you should have SERIOUS cooling and charging issues.

 

[houstonstangguy]

i have one on my coupe too (see sig).

when we were dynoing a few months ago we had 331 to the wheels and he added that small ass pulley and a different alt. pulley, swapped the belt to bypass the smog pump and it jumped to 347 to the wheels. i was quite impressed.

it is a race pulley. i had never seen one that small before either. i didnt have charging problems for 7 months but then my stock alt. went bad (not because of the pulley) and i upgraded to the 130.