The head was sent off to the machine shop to be checked before it went back on.

Right now I am just hating driving this thing since I still haven't put a boost controller on there. I can push hard and get it to 24 psi, but that's about it.

Also, EGT's seem a lot higher at cruising speed now... like around 900... is that normal? I coulda sworn it was a lot lower, and I was seeing lower boost numbers at cruising speed as well before these "repairs"?

 

The stock headgaskets are fairly tough...I'm rinning 60+psi on mine right now with the new twins I'm on VERY borrowed time, and I'll probably be paying intrest on it soon

Chris

BTW, I have stock head bolts, stock head gasket, and 315K miles and counting! The last 100K have been at 325+hp, and saw A LOT of 40psi+ runs with the stock turbo (until it blew up)

 

''Also, EGT's seem a lot higher at cruising speed now... like around 900... is that normal? I coulda sworn it was a lot lower, and I was seeing lower boost numbers at cruising speed as well before these "repairs"?''

Pardon me for butting in here, but something is not right with those numbers. My gut feeling is that your timing has slipped drastically.

 

Timing could have slipped, or the wastegate is fluttering open and closed causing low boost...what is you're boost @ cruise?

Chris

 

Boost at cruise varies between 10 and 20 for the most part.

 

10-20? Yikes! define "cruise"?

ex - at 70mph, I'm 650-700° with 5-7psi with my flying brick.

 

Depinately sounds like the timings way low! My truck at 13* cruises at less than 15psi @70...depending on wind! The flatbed really sucks wind!!!!


Chris

 

You can adjust the wastegate to limit boost also. I have mine set to limit it to 40 psi, and I need to lower it some more.

I see about 9 psi at 65 mph (2200 rpm, egt 650).....is that bad or something

 

70-75, level ground, empty car hauler trailer, it will never see below 10 psi.

 

oh, you didn't mention you had 4 more tires rolling along..

Still sounds a little high.

 

OK, Just for you DRM, I hooked up my car hauler and drove to work...

Level ground. 70-75mph actual speed.. 6-9psi, 700-750° pre-turbo.

methinks you have a boost leak.

 

I gotta find a new shop

 

True, but your stock 12Cm housing is choking long before the compressor's off the map.

Timing has WAY more effect on cylinder pressure and possible HG failure than does any particular boost number.

 

I'm pushing between 10-20psi cruising at 75 or 80mph and around 800 to 900* EGT.............................oh whoops I forgot to mention I have 38's and stock 3.54 gears Man I need to get those swapped out



~Nick

 

Ok, I bought and installed one of these. After a little adjusting I can run 26 lbs, and occasionally spike it up around 28. The truck feels a bit more like it used to, but I want to adjust it more to get boost to top out at more like 32.

EGT's seemed to have dropped to more like 850, which is heading the right direction.

When I have the 3k GSK installed I'll have the timing set then and I should be ok... I hope!