My buddy just bought a 99 Si with a Jackson Racing Supercharger Kit. We went to refresh everything this weekend because the car had been sitting forever. We compression tested the motor and the came up with (1-->4): 148-150-148-162. What should the compression test results be? They're all within 90% of each other, which is good, but I'm not familiar with what range they should be in for that engine.
Thanks!

 

Someone can correct me if I am wrong, but I would think that engine should be seeing atleast 160 in all cylinders if it were healthy. I know I've seen compression results upwards of 185-200.

How many miles are on that engine? How long has it been boosted? How much boost?

 

just under 48K miles, but I have a feeling it was a guinea pig for a shop to test their e-manage tuning skills. It runs horribly rich, so it was tuned seemingly very conservatively. I think the kit pushes 7 psi at the most.

Those numbers sounded really low to me too, I just wanted to confirm it. I'm usually a nissan guy...

 

Just for future reference, I talked to a dealership today and they said anywhere from 150 to 180 is ok with a 10% drop between cylinders. It's completely out of spec if the drop is 25% on any cylinders.