stock boost levels
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Freshman User
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stock boost levels
Search says 18-20psi. I'm hitting 14 psi during a WOT 50-70mph run in 6th gear. Noticed some exhaust smoke coming from behind the turbo on this mornings cold start. Leaky stock up pipes I'm sure. Any urgency in addressing this now? Got lots of spring/summer projects that will require the truck, planning on pulling motor as next winters project (oil pan replacement among other things)
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Joined: May 2014
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From: Lake Hartwell, GA
18-20 is pretty good for a stock system. Do a WOT from 3rd, then 4th and see what boost numbers you hit. 5th gear is meant for cruising really and the power is in 2-4 for the ZF6. When towing, I use 5th gear on flat land and slow rolling grades. Into the mountains the truck is in 4th gear towing up and 5th gear without a load.
Leaks are not efficient and should be addressed. Less dangerous on the exhaust side though than the intake.
Leaks are not efficient and should be addressed. Less dangerous on the exhaust side though than the intake.
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Freshman User
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Just to be clear, I'm not getting 18-20psi at any point. 14psi max in any gear. Real question is will this low boost (from up pipe leaks/other boost leak) cause additional issues? There will be very limited use- 6-12 trips over the summer to the dump, gravel and firewood hauling. If I do pull the motor now it will be down when I need it the most. Motor pull scheduled for next winter to address all PM issues, replace oil pan and a few reliability upgrades.
More Turbo
Joined: May 2016
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The Service Manual says..... "Road Test - select appropriate gear to obtain desired engine speed and full load on engine (best accomplished climbing hill or truck fully loaded). Spec: MGP 15 PSIG Min"
So, a Stock truck should reach 15 PSIG Boost. There is no mention of a top number. 1 lb difference? or exaggerated readings? I would say Gauge or Sender.
You could make an inexpensive Boost Leak Tester to determine if there is a leak in the system. Most often, just "snugging" the CAC Clamps can overcome a pound or two.
So, a Stock truck should reach 15 PSIG Boost. There is no mention of a top number. 1 lb difference? or exaggerated readings? I would say Gauge or Sender.
You could make an inexpensive Boost Leak Tester to determine if there is a leak in the system. Most often, just "snugging" the CAC Clamps can overcome a pound or two.
Hotshot
Joined: Jan 2011
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From: Puget Sound
Stock configuration is 17-18 PSI max. Anything over that and something has been tinkered with - like the wastegate actuator.
14 PSI is not good if it's there because of leaks and you're getting soot. I would urge you to at least get either an EGT gauge on the offending manifold, or both EGT gauges. This way, you can actually see what you are doing to your engine - and drive accordingly. If you find you can't tow the speed limit because of EGTs, then that will be your deciding factor.
Oh... my whole exhaust system from the block out has been replaced without pulling the engine.
14 PSI is not good if it's there because of leaks and you're getting soot. I would urge you to at least get either an EGT gauge on the offending manifold, or both EGT gauges. This way, you can actually see what you are doing to your engine - and drive accordingly. If you find you can't tow the speed limit because of EGTs, then that will be your deciding factor.
Oh... my whole exhaust system from the block out has been replaced without pulling the engine.
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I'm at 24 lbs with the red line capped. Was at 8-12 until I fixed my leaks. I don't have any tuning done, just intake and exhaust.
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Post Fiend
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From: Parker, CO
Just to be clear, I'm not getting 18-20psi at any point. 14psi max in any gear. Real question is will this low boost (from up pipe leaks/other boost leak) cause additional issues? There will be very limited use- 6-12 trips over the summer to the dump, gravel and firewood hauling. If I do pull the motor now it will be down when I need it the most. Motor pull scheduled for next winter to address all PM issues, replace oil pan and a few reliability upgrades.
More Turbo
Joined: Nov 2016
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From: SGV SoCal
ZachinCo,
You may want to check for leaks.
Stock injectors 240K, 4" with wheel upgrade and 6 pos tune on 70hp is good for at least 25PSIG.
That is W/O upgreading to bellows. I can do that unloaded on a on-ramp with out trying too hard.
You may want to check for leaks.
Stock injectors 240K, 4" with wheel upgrade and 6 pos tune on 70hp is good for at least 25PSIG.
That is W/O upgreading to bellows. I can do that unloaded on a on-ramp with out trying too hard.
More Turbo
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Thanks!
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Freshman User
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So had some time yesterday and fabricated a boost leak checker and pressurized the intake to 15 psi- no leaks obvious on the intake side.
Ordered up-pipes this morning and about the order the turbo install kit required when R&R the turbo. What else becomes easy to do and a no brainer when the turbo and up-pipes are off?
Ordered up-pipes this morning and about the order the turbo install kit required when R&R the turbo. What else becomes easy to do and a no brainer when the turbo and up-pipes are off?
Lead Driver
Joined: Dec 2006
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From: San Diego, CA
Things to do with the turbo out are:
- EBPV rebuild/replace/delete
- Rebuild the turbo
- Adjust/replace wastegate controller
- New turbo wheel
- install downpipe
- Passenger side fuel line (there is a tendency for it to rub through the metal line at the bracket about half way back).
Obviously nothing is required but these are all things I did when I had the turbo out for a bad oil leak a few years ago. I would definitely check the fuel line on the passenger's side for rubbing. I put some thin rubber in the bracket to minimize/prevent wear. I'm not sure how many miles are on your truck but a turbo rebuild is not expensive, just time consuming. I consider it an ounce of prevention. If you do it, make sure you have a 1/4" drive 8mm deep socket (12 point) or you won't get to some of the bolts. You're already doing the up-pipes.
None of these are required but sure are a lot more convenient if you already have the turbo out. These are all things that I did while I had everything out so I wouldn't have to go back there. Others will have ideas too but that's my .02
- EBPV rebuild/replace/delete
- Rebuild the turbo
- Adjust/replace wastegate controller
- New turbo wheel
- install downpipe
- Passenger side fuel line (there is a tendency for it to rub through the metal line at the bracket about half way back).
Obviously nothing is required but these are all things I did when I had the turbo out for a bad oil leak a few years ago. I would definitely check the fuel line on the passenger's side for rubbing. I put some thin rubber in the bracket to minimize/prevent wear. I'm not sure how many miles are on your truck but a turbo rebuild is not expensive, just time consuming. I consider it an ounce of prevention. If you do it, make sure you have a 1/4" drive 8mm deep socket (12 point) or you won't get to some of the bolts. You're already doing the up-pipes.
None of these are required but sure are a lot more convenient if you already have the turbo out. These are all things that I did while I had everything out so I wouldn't have to go back there. Others will have ideas too but that's my .02
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