**Boost = Maximum blower boost**
**14.7 = PSI at sea level CR = Engine Compression Ratio**
Altitude plays an important role in determining compression ratios. If the altitude in the area where you normally drive is significantly higher than sea level, then your compression ratios will also vary. To determine the effects of the altitude on a calculated compression ratio, use the following formula: Corrected Compression Ratio = FRC – [(altitude/1000)x 0.2] |