Originally Posted by SkySkiJason

My stock turbo in F350 had over 300k miles on it and more than 100k making 25+ psi. I did replace it with a 38R at engine rebuild, but that turbo is still TIGHT and has never even been rebuilt. It has also never seen surge and was NEVER shut down above 400* EGT.

That said, the turbo in my X was 'dusted' badly when I bought it over 100k miles ago - then pushed to nearly 30psi regularly after that. It failed catastrophically a few months ago...

Like buzzkill said though boost psi is over-rated. We need VOLUME of air to make power and psi doesn't accurately represent that. Moreover, it is excessive DRIVE PRESSURE that kills turbos - specifically drive pressure vs boost pressure - this is what puts ridiculous sideloading on the shaft/journal bearings and if you combine deadly drive pressure ratios with even a little surge/stall, it won't take long to kill any turbo. The wastegate is there to reduce the amount of backpressure, so y'all with the little red line plugged have removed the lifeboat from your turbo AND yer not making any more power anyway...

Notice the van turbo has no WG?? Thats because it has a larger exhaust wheel and a larger exhaust housing, so drive pressure is not an issue (with stock injectors, etc anyway!!! All those ported housings, WW's and larger AR exhaust housings for stock turbos are not a good investment IMHO. Van turbos are cheaper and likely work better too!

As for headstuds, the stock bolts are generally considered OK up to about 40psi. Even then, you're just looking at popping headgaskets - not likely a catastrophic failure.

Want mo power? Stage 2 injectors (80-100% over nozzles) and a T4-type turbo/modded H2E. Should be 500ish HP, tow like a locomotive and be able to return better-than-stock MPG's!