underdrive pulleys and supercharger

[stang94X]

i was told i cant run my underdrive pulleys with my supercharger that will be going on soon, is this true?

 

[Mr.Bolt-on]

Well, as from what I've seen the supercharger kits come with pulleys that are the correct size for your supercharger. I've also been told the same thing, you can't use underdrive pulleys with a supercharger. I may be wrong, but I too was wondering the exact same thing.

 

[stang94X]

the crank pulley is going to be changed to a 6" with a overdrive 7" supercharger crank pulley, but i still have the underdrive pulleys on the alternator and water pump, thats what i was wondering about, i dont see how the pulleys would affect anything but i dont know

 

[Dalamar]

it would turn the blower slower.
I think underdrives are a waste of time and money, and messes up your idle alternator voltage output.

 

[stang94X]

the crank pulley thats on the crank now is 6" and the pulley that is going to be put on is 6 1/2" that will driving the accessories and the pulley that will be driving the supercharger is 7", will that 1/2" difference in the crank pulley thats driving the accessories mess anything up, should i just put the stock alternator and water pump pulleys back on, i dont care about having the underdrive pulleys, the only reason why they are there is cause they are nice looking aluminum pieces