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+--- Thread: 45lbs boost (/showthread.php?tid=6297)
45lbs boost - Hambone - 06-18-2020
Cm 870 cracks a steady 44lbs boost. Been chasing this demon,my ? Is can the wiring that controls the turbo control box be shorted to high to trick truck into creating more boost.on cruise going down hwy itll run a steady 35lb pulling a hill however if your jumping on interstate it'll boost to 44-45 and hold.
RE: 45lbs boost - marek4792 - 06-18-2020
Is it demandated? Did you do an egr tuneup?Cm870s are known for their boost spiking when accelerating. But then drop back to 35-38 lbs depending on your power rating.
RE: 45lbs boost - tree98 - 06-18-2020
I believe a bad egr valve will cause that much boost on an 870. Don't let it get that high or your gonna crack a piston or the head.
RE: 45lbs boost - Hambone - 06-18-2020
Completely demandated. I've worked with mommaburt on programming for a while now. I actually had the engine completely overhauled 30k ago. New head,injectors,updated oil pump and cooler etc. Was built to max out at 565hp currently have it set at 500 pyro rarely gets over 600 degrees. However it cracks 45lbs boost and i am worried about blowing head,just wasn't sure if turbo control box wiring or box itself could short high and cause problem as I'm getting no faults
RE: 45lbs boost - Rawze - 06-18-2020
You never fixed this same issue your were complaining about over year ago? -- http://rawze.com/forums/showthread.php?tid=4656&pid=39877#pid39877
RE: 45lbs boost - Hambone - 06-18-2020
I've worked with programming,replaced acuator,turbo control box,boost sensor,cac pressure checked system replaced boots,and replaced turbo a year ago and it always does it. That's why i was asking about wiring.
RE: 45lbs boost - Rawze - 06-18-2020
maybe take a trip to Mr. hags and let him troubleshoot it.. he has worked a lot with those 870 turbo when they act up and have mysterious issues like that.
RE: 45lbs boost - Hambone - 06-18-2020
If it persists I will. I appreciate all advice and criticism from everyone.