ka-t's have lasted years on 6 psi and stock..... it really is a hit and miss though. check out ka-t.org's forums, their tech section is unbelievably amazing. Also mean if you want to see the 500whp stock internal kade dyno + vid it's over there in the dyno section as well.... I can't remember how long it survived of if its blown yet, but I do remember it was damn impressive for stock ka internals.