Still on the head shims, how do i change them according to the altitude. If i race at sea level what should be a good start point in head shims and also if i go race in a place which is 1000Meters (3280.83 feet)? Another question how should i change the head shims according to the Temperature/Humidity ?

Thanks in advance.

I almost forgot, i run 30%. (RB MATRIX ENGINE)