Test is the same as a N/A car.
Pull the plugs, block open the throttle, pull the DME relay, and crank the engine.
Good numbers for a turbo depend on your altitude.
The compression ratio of a 951 is 8.0:1, however there is some heating of the air as it is compressed, and normally you see numbers around 10:1. So, if you're at sea level, the air pressure should be ~14.7psi, so you should see compression numbers of 150psi, at 5000 feet, it's around 12.1psi, so you should see 120psi on your compression test. Keep in mind, these are ideal values, so if you see within 10% of them, you're in great shape.
If you see much less than those values, time for a leak-down test, but you probably know that
