I have a duramax 6.6 LMM turbo diesel in my 2003 H-1 Hummer wagon. I recently installed a auto meter boost gauge that reads 30.1 under heavy accleration wide open throttle. Is that boost low, medium, or high? I am new to diesel engines except back in the 60's I drove my dads IH 560 diesel with a Turbo charger by M and W with a straight pipe that worked great plowing fields and made tons of smoke! Please tell me what you think!

 

Is everything on the engine stock? 30 psi would seem normal to me. I can easily hit 35psi on my stock turbo. As long as you have no codes and functions as it should you should be ok to keep going.

 

30 seems high for stock programming, my 06 LBZ only spiked 26 and leveled at 24 on hard pulls with a blocked egr and stock setting. Highest tune only saw 30 and backed to 28-29.