LLY Boost Pressure

[oilfield_trash]

How much boost pressure is my stock LLY motor running?

 

Also, is the turbo a GM proprietary turbo or made by somebody else? What model?

[dannyukonxl]

umm... dont quote me but i remember reading 60 psi?... i thought it was incredibly high but just remember that number. And i think garrett/ honeywell does the turbos for nearly all stock applications

[Machine]

How much boost pressure is my stock LLY motor running?

 

Also, is the turbo a GM proprietary turbo or made by somebody else? What model?

 

<{POST_SNAPBACK}>

 

 

 

Eric,

 

According to GM, max boost for a stock LLY Garrett Turbo is 20 psi.

[duramaxHD]

60 PSI would blow your head gaskets sky high. You can install head studs and then run all the boost you want...but until then the engine can only take 47 PSI or so. The LLY turbo is a VVT (variable vane turbo) design made by Garrett. It does not have a wastegate or anything. The max boost is controlled purely by the setting that the ECM commands of the vanes in the turbo. I beleive 23 PSI is the maximum that it will command, but products such as PPE's Boost controller can take it up to 40 PSI. However the design nature of the VVT makes it useless at that much boost. The drive pressure for the turbo exceeds 80 PSI at 40 PSI of boost so you are creating more back pressure than boost and therefore robbing a lot of power from the engine. The max boost you can make with a stock LLY hairdryer and still be efficent/useful is around 32-34 PSI.

 

---ben