Hi Guys,

Just hoping to get some answers.

I have a 1990 Mustang GT with the 5.0L and I have added GT40 Intake and Heads. I have also added a Powerdyne Super charger.

The question I have is that I could only pump out 4-5lbs of boost. Supposedly it should pump out 8lbs.

Would an Under Drive Pully Kit cause this?? Since I have that istalled also.

Or Could it be that the GT40 Intake and Heads give no resistance??

Just wondering. I have had this problem since it was first installed.

I know I am just grasping for straws but any help would be greatly appreciated.

Thanks in Advance
Peter

 

Could be the belt slipping. Common issue in this type of application.

 

I am sure it is a minor issue and shortly you will have many educated replies-good luck

 

That is the problem... An underdrive pulley slows down the speed of your accessories, one of which is the blower.

 

I missed that. That would cause your issue for sure.

 

Remove the pulley and you'll be golden.

 

So do you mean to put all the original pully back on?

or

Do mean, put a smaller pully on the Super Charger

Thanks
Peter

 

I am a big fan of stock, other guys not so much. New answers coming shortly lol

 

Ditch your underdrive pulleys and go back to stock. Once you know where you are at you can look into a smaller blower pulley to get even more out of it if you choose.

 

If you want more power through pullies, throw the underdrives in the garbage and put a bigger crank pully on (overspeeds the blower), or a smaller blower pully on (overspeeds the blower).