Can someone explain to me how to look up the vaccuum on the commander and what the hell is vaccumm?

Also, how would I know the compression on my FD?

 

You'll see vacuum when you're monitoring boost. Numbers greater than zero will be represented in kg/cm^2, such as 0.70. Numbers less than zero (vacuum) will be represented in mmHg. -450 mmHg of vacuum is about what you want to see on the commander when idling.

To convert these number from metric to imperial, go here.

Compression tests require a special tool and are best left to a qualified shop.

-Scott