question about boost

[06ramcummins]

I just installed a 64/71/13ss on my truck. from the factory the turbo was set at 42 psi. Even with this new turbo i can still hit 1600 degrees wot pretty quick. So increased the wastegate to 48 psi and I still can hit 1600 pretty quick. Shouldn't this turbo keep me a lot cooler than what it is?

 

[joefarmer]

Check for boost leaks. They're pretty common and a relatively tiny leak will add 300-400F of EGT.