How to add a turbo to a non turbo car.

The basic reason for forced induction (turbo or supercharger) is not to increase compression or the maximum pressure in an engine cylinder, it is to increase volumetric efficiency (the efficiency of the engine at drawing in air) although forced induction is the most effective method of upping compression.

In computer games we just tick a box, and within seconds our car is fully turbocharged and running much faster. In the real world things are very different.