This is a VERY common question about turbos/superchargers. Many people will chime in and say “6-8 PSI on stock internals”. This is not always true. When adding a form of “Forced Induction” you are ramming tons of extra air into the motor, mixing this with more fuel creates more power. All “FI” setups are different, but remember this, you can add 50% more power to your car safely with a good tune, and keep the reliability aspect. Higher numbers can be achieved with a Great tune, and you can still have daily driving reliability. If you plan on using a boost reliant FMU then 6-8 will most likely be okay, but with proper tuning a stock motor can handle much more than 6-8 PSI. In some applications the tune can make more than enough power at lower boost levels, it just depends on the setup. So remember, that whole “6-8 PSI” rumor isn’t 100% true.