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Whats the practical boost limit for the stock turbo? I think stock it maxes at 20PSI, but with a boost controller whats the highest you should go for everyday use? I was thinking something in the 25-27 range, correct me if I'm wrong.
 

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once you get into the 30's you're pushing it., i would never run mine over 30
 

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i can get my 06lly to 27 but that is the highest so far
 

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32psi OK....... 34psi your chances of death are almost 99%

I ran 32 psi for a long time with no issues, when i pulled the charger off and inspected it it still was in A1 shape!!!
 

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40 psi. max
 

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my turbo :blowup at 27 psi...:eek:

although i do believe it to be a rare occurance, it still happened.
 

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shit mine hits 31 all tha time and i have never had any problems....and my buddies have the ppe boost builder thing and hits 36 and he has had no problems...i guess it just depends on everything i dunno..
 

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shit mine hits 31 all tha time and i have never had any problems....and my buddies have the ppe boost builder thing and hits 36 and he has had no problems...i guess it just depends on everything i dunno..
The LLY and LBZ chargers can take a bit more boost than the LB7. I still like it around 30 with maybe spiking to 31-32psi max on the LBZ.
 

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You all need to qualify where the reading is taken. If using the factory sensor, 30 psi will be 36 psi at the compressor discharge location.

So if you are using an installed sensor, without knowing where it located, this information is meaningless, and turns this thread into another economy thread.

Stock tuning does not command 27 psi. If reading from the bus, then you are using a tune, and that should be disclosed.
 

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GM says that 20psi is max on the LMM. I currently am running PPE's level 3 tune and don't have a boost or pyrometer yet, how much more boost do you guys think I might be seeing over stock?

Randy
 

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GM says that 20psi is max on the LMM. I currently am running PPE's level 3 tune and don't have a boost or pyrometer yet, how much more boost do you guys think I might be seeing over stock?

Randy
LMM's can reach really high boost with tuners. I have to actually lower the factory boost tables with EFI to stay around 30psi when adding fuel. Might want to get a gauge on it.

LB7 and anything over 32psi and you're playing with fire.
The VVT's can take a bigger boost hit and live, but off it's map anyway over low 30's.
 

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i can hit 34 no problems "knock on wood". and i just hit 31000 miles so i dont know i think it depends on the turbo
 

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My reading is also taken at the charge pipe and spikes at 35psi. This is with a kennedy boost stick, egr blocked, fingerstick, 4" dp back, intake, and triple dog on performance.
 

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my edge would read like 32-34 just depends and during the 4-5 shift it would spkie to 36 is that an accuraute reading or no.
 

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my edge would read like 32-34 just depends and during the 4-5 shift it would spkie to 36 is that an accuraute reading or no.
I take it you have the edge stacked with the PPE, since the Edge alone won't command that much boost.

That should be accurate as long as nothing is tethered to the MAP sensor. But the actual pressure created by the turbo, upstream of all your plumbing resistance losses, will be more like 38-40 psi. That's cooking way off the compressor map, wouldn't expect to have much longevity if you do it frequently.
 
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