Eaton supercharger problem - No boost

[SuperRunner]

[FONT=Verdana, Arial, Helvetica][FONT=Verdana, Arial, Helvetica] I have an M90 supercharger and I am experiencing a boost problem.

It is a ford thunderbird so there is no internal bypass, so I am not losing pressure through that.

I took off the drive belt hooked up my pressure test tool to the throttle body and was able have the manifold hold 30psi while the rotors were spinning. I stopped the rotors from spinning and the manifold was still able to hold 30psi. There was maybe 1psi drop between the throttle body and the manifold.

Is that ok for a roots supercharger to leak that much?[/FONT][/FONT]

 

[mshawari1]

What is the drive ratio you have there ​

 

[SuperRunner]

3.2" pully I think. I have a 2.5" that I will be putting on.

 

[Cobra]

The problem is that the 1uz crank pulley is too small. Increase its size or reduce the pulley size on the m90. Install the 2.5 and make sure it doesn't foul on the blower snout.

 

[SuperRunner]

I dunno, I would think I would at least see some boost. But you could be right.

 

[JustenGT8]

I saw 5psi with a 3 inch pulley so yeah you should see some boost

 

[Cobber]

http://lextreme.com/forums/showthread.php?p=90427#post90427

Check out your idle speed control valve.

 

[SuperRunner]

That was it, THANKS!!!!! Hmm, is it not designed to close? Or maybe something is wrong with it.