Street Engine Compression Ratio??

This is a loaded question really. We need the intended use of the car. The reason to keep some compression in the engine and not run as much boost is to keep the charge temp cooler. “Pressure is not just pressure” in the combustion chamber. There are many factors at play. Spinning the blower harder and harder has a rate of diminishing returns. The harder you spin the blower the more heat it makes and and power goes away quickly. So, for a street car the best choice is always a compromise. Run a nice static compression of around 9:1 and keep the engine snappy when out of boost, and not terribly high to run into problems with chamber temp and detonation when in boost on pump gas. As said timing is always super critical. So is fuel selection. The fuel selection dictates timing and the amount of power you can potentially make.