I am looking at a 1997 with 80k with the 12v CTD. It has the complete banks powerpack. When gettin on it it is pulling right at 30psi on the boost gauge, I am concered is that to much, I have herd that mid 20's is all you want to go. Any info would be great thanks.
Nick

 

Mid to upper 30s is fine

 

Your fine. An HX35 is good to the mid-upper 30's (i.e. 36-38) before it starts to generate a lot of heat. The head gasket is probably good to lower-mid 40's before its in jeopardy of blowing due to excessive pressures. I'd just try not to bark the turbo too much at high pressures (let off the pedal quickly from full boost). It's not much of an issue on the HX35's but I feel it's better to be safe than sorry.

 

What will "as you say "barking"" the turbo do?

 

my truck will top out around 34 lbs of boost, I have seen no problems... yet...

 

In severe cases it can snap the turbo impeller off the shaft or break off fins.
Bark is easy to avoid, you just have to get into the habit of letting up on the throttle somewhat slowly rather than all at once.

 

Thank you I have not heard that terminology before now!

 

Not knowing a thing about turbo's, just what I've read here.

It seems that the "safe" boost level for a particular turbo somewhat matches it's designation.

I.E.

An HX or HY35 can safely produce 35psi.

An HX40 can do 40lbs.

Once you get out of the "H's" this theory goes out the window though.


phox

 

When something is spinning at 140,000 RPMs or more, and it loses a blade and becomes unbalanced, things get spectacular real quick. The turbine will literally starts sending pieces of itself in diferent directions, at very high speed. I would try not to bark the turbo. These things are expensive if they break.

 

Another effect of turbo barking I've seen but didn't mention is that it can blow the factory airbox open or blow an aftermarket hose clamped filter off the tube.
You could be driving around sucking up unfiltered air till the next time you open the hood.
One advantage to barking, if it doesn't blow the filter off, is that it back flushes the filter.

 

zcc

 

Not quite right.. as was said once the HX hits 36-37lbs its out of its efficency range and just moving hot air but 35 lbs is no problem for it. Dont want to exceed 40 lbs and 45 is the point of destruction. However I have heard of a HX-35 hittin 48 lbs in a few cases and living to tell about with no problems.

The HY-35 on the other hand is a little lower. Dont wanna go past 30 lbs, 35 lbs is Its point of very possible failure.

In short, best max operation range for efficency AND safety..
HY-35 24-29lbs
HX-35 34-39lbs
HX-40 40ish. Dont know as much about that one but it'll handle 40 lbs no prob.
My .02