This is an easy way to consider it. Take the power your motor makes NA. Then @7.35lbs assume you will add 50% more power. If you add 14.7lbs you will double your HP. This is a rough rule of thumb with a lot of variables. This is why a motor that makes 300hp can jump to 600hp with 15lbs. This is also why a more powerful motor NA will make much more power with the same boost.
Hence if you have a more powerful higher compression motor it will take less boost to make the same power. This can be applied to many changes that may be made.