Firstly, if you add boost beyond the factory specs, you are not going to get any more performance out of the vehicle unless you add more fuel.

If you add more fuel without an intercooler, you risk melting a piston, depending on how long this additional power is present for. You might get away with 15 seconds however, 2 minutes would be a killer. Nobody knows and it depends on your specific engine.

So, anyone who is modifying these engines for more boost and fuel is well advised to add an accurate EGT gauge that you can monitor constantly from the driver's seat. Making adjustments without it is simply playing russian roulette with a very expensive engine.