On my sn2000 I just put new races, impeller shaft and balls in it. Now it hits 5psi and drops to vacuum on the gauge. Do I need to reshim it when going to new races? Before I was seeing 7-8 psi at the manifold...
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On my sn2000 I just put new races, impeller shaft and balls in it. Now it hits 5psi and drops to vacuum on the gauge. Do I need to reshim it when going to new races? Before I was seeing 7-8 psi at the manifold...
5psi is normal for an SN unit. Do you have the upgraded or the stock impeller?
Upgraded. Even if it stayed at 5psi I wouldn't mind but it literally falls back to no boost afterwards. Even when it was whining before I took it apart it was making more boost than that on the gauge and didn't just drop off(I am not even going to 5k rpms when this happens). Is this indicative of not enough pressure on the balls?
How much ballpressure do you have ?So how much force to turn the pulley ?
Do you have beltslip ? check for black pouder around the sc pulley.
All rubber hoses tight ?
Don't think, but measure.
Use a torque wrench, it should take between 28 lbs/f and 35 lbs/f to turn the pulley.
I and others have found out that tightning the frontcase cover bolts also tightens the ball pressure.
It does sound like your lite on the ball pressure.
Talked to craig and he agreed. Got some shims on the way.:)