With the last round of upgrades to the cummins in my 93 Dodge 1 ton Dooley, It will make 33 pounds of boost. That's about double what it originally made. Am I looking for trouble?

Modifications include a bigger turbo, bigger injectors, turned up VE series pump, four-inch exhaust.
What is the most boost that these engines can handle and remain reliable?
What are the common failure modes? I have an EGT gauge.

Thanks, Joel

Mine is a 2nd gen and it regularly boosts 40psi, even towing without a problem. I'd say your safe at 33 if you don't let the egt run too hot for too long. If you over boost it, you could end up needed a head gasket.

This would be a good thread to have for all Gens.
I've wondered for quite a while what safe boost is. I have my warning set at 31psi and I hear "her" scolding me quite often.

Thanks for the helpful reply's!

It certainly has all the power I need now, I can't see any need to even exceed 25 psi for more than 10 or 15 seconds.

Hopefully the trans holds up. It's an A518 that has been beefed up and a DTT converter.

No diesel expert at all (or even a novice) but I've read somewhere that once you hit the 50 psi range you should add head studs and fire rings in the head gaskets, but that's just something I've read, hopefully one of the diesel guys can shed some light on this statement

Drove a buddies 6-speed all turned up....40psi was about half throttle, what a blast!

They estimate 35psi before studs and fire rings and all but each engine handles it differently. My dad had a 94/95 second gen running 40psi without issue. Currently working on a friends 92 first gen and he was seein 28-30 and belching black, i changed so stuff around and what i changed increased his airflow capability and dropped his boost to 22psi WOT and cleaned up his exhaust, still have more to do. I am also building a first gen engine out of a 92 and switch to a ppump and doin alot of other things like twins and i'm setting to try and be around 32psi but making alot of cfm

I have run 30psi in my 92 for years with no problems. my buddy runs at 40psi in his 93 and his headgasket has started to weep a bit. (150000k since it was cranked up)

In my personal experience, about 40-45 psi seems to be the point that things start to give up. Every truck is different and will react a little differently. If you decide to put more than about 40 psi to it then it's time to start looking at studs and O-rings in the cylinder head. I would stay away from fire rings unless it's a race only truck as they tend to get brittle and break from all the warm up/cool down cycles of daily driving.

The wastegate on my 92 with a Banks turbo is factory set at 22psi.

Ed