sideshow_bob wrote:boost also adds heat to motor, also more fuel adds heat, if egt's can be kept down more power can be made by been able to add more boost, or do u know of some good info for me to read. from what i have seen n read most failures r coursed by heat issues
You're right about heat causing problems.
But the air doesn't cause the heat, the fuel does. EGTs are pushed up by fuel, not air. Lean in a diesel means cool - opposite to petrol.
Extra boost (up to a point) combined with a modest amount of extra fuel can actually cool things down, by pushing more cool air through the engine, particularly when both valves are open (overlap) and combustion isn't happening.
Without being brand/model/boost PSI specific, it is quite possible to up boost, tune accordingly, get worthwhile power gains, maintain or lower standard EGTs, and decrease fuel consumption.
As has been said elsewhere, extra power and torque, particularly if used, will increase stress and wear, although it's hard to accurately say how because of the variables. This is a separate issue from the effects of boost.
Another issue that only each owner can decide on, is whether or not the benefits are worth the stuffing around. They will be for some and not for others.