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Car won't boost above 0.5

 
  #16  
Old 10-05-2010, 06:22 PM
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Have you serviced your DV's ? I recently took mine apart, cleaned and regreased (Mobil 1 red syn grease, or white lithium) . I've always tested mine by pushing in the diaphragm from the bottom while applying suction to the nipple. The diaphragm should stay in the upright position without any assistance until the suction is released, when the suction is released it should release all the way back down without sticking. Repeat a few times.

I would assume you would see about .8 all the way to redline if you were running off the wastegate spring (assumming 1 bar actuators), and no leaks.

Wish I could offer more, I went through this with Todd @ Protomotive recently. I also ran a pressure test at about 20 psi, and checked for leaks.

Good luck.
 

Last edited by JSBear; 10-05-2010 at 06:25 PM.
  #17  
Old 10-05-2010, 07:18 PM
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Do a pressure test from the turbos like I suggested via email... all your problems will show up.... forget doing the dvs test this and that.. the leak test as I suggested does all of that and much more.... trust me...

also, inspect the turbos... the compressor.. make sure they are not hitting the housing as they spin...
 
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  #18  
Old 10-05-2010, 07:44 PM
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Originally Posted by [email protected] View Post
Do a pressure test from the turbos like I suggested via email... all your problems will show up.... forget doing the dvs test this and that.. the leak test as I suggested does all of that and much more.... trust me...

also, inspect the turbos... the compressor.. make sure they are not hitting the housing as they spin...
Thanks for the input Markski and the problem would most likely be mechanical in which would be found as you suggested.

Give me a call tomorrow and I will let my desk know.


Best Regards,
Scott
 
  #19  
Old 10-05-2010, 07:48 PM
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Originally Posted by Softronic View Post
Thanks for the input Markski and the problem would most likely be mechanical in which would be found as you suggested.

Give me a call tomorrow and I will let my desk know.


Best Regards,
Scott
No problem,
thanks
mark
 
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  #20  
Old 10-05-2010, 07:53 PM
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Originally Posted by MBailey View Post
I would guess a hose has come loose and is dumping all the boost once the system gets to 0.5 bar. Simply pressure up the system at the turbo inlet and listen for leaks.
I agree. Check you hose connections carefully. I bet one is not securely fastened, especially since you are hearing a loud whoosh at higher boost.
 
  #21  
Old 10-05-2010, 11:35 PM
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Thanks everyone for your inputs! Inspector, MBailey, Earl, Markski (as always), Scott, TTDude, Neil @ Switzer, Jake @ Tial, and Mark @ Agency Power

MY mechanics will hopefully have this solved tomorrow.
 

Last edited by bad107; 10-05-2010 at 11:37 PM.
  #22  
Old 10-06-2010, 02:23 AM
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Good luck!
 
  #23  
Old 10-06-2010, 02:29 PM
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If the intake is collapsing above the engine, wouldn't that cause the diverter valves to open up?
 
  #24  
Old 10-06-2010, 02:49 PM
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Originally Posted by bad107 View Post
If the intake is collapsing above the engine, wouldn't that cause the diverter valves to open up?
Do you mean the intake pipes are collapsing presumably from vacuum? This would kill the boost but I dont think it would cause the valves to open up and give a whooshing sound you describe.

Why are you asking this?
 
  #25  
Old 10-06-2010, 03:33 PM
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if you have a leak before the turbo that would not cause your problem.. that is the non pressure side...
 
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  #26  
Old 10-06-2010, 04:08 PM
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Originally Posted by bad107 View Post
If the intake is collapsing above the engine, wouldn't that cause the diverter valves to open up?
shouldn't, but what intake piping do you have!? If you're at 0.6bar with the throttle open, the DVs should be shut.
 
  #27  
Old 10-06-2010, 04:41 PM
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The guys pressure tested everything..found a few small leaks and tightened everything up. Nothing changed.

The car is boosting up to .8 or .9 then immediately drops to 0.53 bar stable.

Mechanics think it is the intake piping above the engine.

Next step is to dyno the car with the turbos open to the air (i will make sure they brush and blow any crap out of the dyno way). If the car makes 1 bar of boost and holds it there we know the intake is in fact the problem.

Sound right?
 
  #28  
Old 10-06-2010, 04:47 PM
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Originally Posted by bad107 View Post
The guys pressure tested everything..found a few small leaks and tightened everything up. Nothing changed.

The car is boosting up to .8 or .9 then immediately drops to 0.53 bar stable.

Mechanics think it is the intake piping above the engine.

Next step is to dyno the car with the turbos open to the air (i will make sure they brush and blow any crap out of the dyno way). If the car makes 1 bar of boost and holds it there we know the intake is in fact the problem.

Sound right?
where did you pressure test from? did you take out the stock N75 grey valve?
what is the greddy reading when car is at idle...
dyno will not solve or find the issue
 
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  #29  
Old 10-06-2010, 05:06 PM
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Originally Posted by bad107 View Post
The guys pressure tested everything..found a few small leaks and tightened everything up. Nothing changed.

The car is boosting up to .8 or .9 then immediately drops to 0.53 bar stable.

Mechanics think it is the intake piping above the engine.

Next step is to dyno the car with the turbos open to the air (i will make sure they brush and blow any crap out of the dyno way). If the car makes 1 bar of boost and holds it there we know the intake is in fact the problem.

Sound right?
Boost is actually a resistance. Are you going to take the hoses off the ouput of the compressor or the input? Either way is bad. Input will allow you to suck stuff in, and won't tell you much, with the output open, that will likely over spin the turbo to reach your target boost...which how are you going to measure if this is open?
 
  #30  
Old 10-06-2010, 05:23 PM
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Ok, so all leaks are fixed and still not boosting. How old are the spark plugs? I had old plugs once and it would not boost past 0.5 bar.
 

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