Cannot make boost with a MBC
#1
Cannot make boost with a MBC
Hi - Here is my problem,
I have a MBC installed between the housing on the turbo and the wastegate.
If I have the w/gate can set to 5PSI - I cannot change boost at all higher regardless of the amount I dial in the MBC - even all the way. Seams that its simply not having any impact.
When I adjust the can I get higher boost -- ??? again independent of the MBC setting.
Then when I was checking it this morning a ball and spring fell out - anyone know what order I put them back in?
C
I have a MBC installed between the housing on the turbo and the wastegate.
If I have the w/gate can set to 5PSI - I cannot change boost at all higher regardless of the amount I dial in the MBC - even all the way. Seams that its simply not having any impact.
When I adjust the can I get higher boost -- ??? again independent of the MBC setting.
Then when I was checking it this morning a ball and spring fell out - anyone know what order I put them back in?
C
#5
OK, clarify a few things.
Your turbo setup was working perfectly fine and would adjust accurately on wastegate spring alone prior to installing the MBC.
You have just bought this MBC, installed it, and it's not doing anything?
Is it new? What is the brand?
You say you can still adjust accurately with the wastegate spring even though the MBC is installed?
Hmmm.... that is strange. I vote that you reassembled it wrong... but it's a pretty simple device and you say you've got it right. Post a couple of pics of the setup... maybe we can narrow it down with a visual. Take the MBC apart and lay the pieces out in the order you're installing them and post a pic of that too.
Your turbo setup was working perfectly fine and would adjust accurately on wastegate spring alone prior to installing the MBC.
You have just bought this MBC, installed it, and it's not doing anything?
Is it new? What is the brand?
You say you can still adjust accurately with the wastegate spring even though the MBC is installed?
Hmmm.... that is strange. I vote that you reassembled it wrong... but it's a pretty simple device and you say you've got it right. Post a couple of pics of the setup... maybe we can narrow it down with a visual. Take the MBC apart and lay the pieces out in the order you're installing them and post a pic of that too.
#7
Well an MBC is a simple device, unless the spring is bad/crappy, or it's a poor design, then I can't see it being a "bad" MBC. They don't just go bad or have "bad batches." Does it have a bleeder so that the wastegate can close when you go off boost?
My thoughts are that the wastegate is blowing open. Do a run with no boost source going to the actuator, if you can't get over 5psi then it's the actuator.
My thoughts are that the wastegate is blowing open. Do a run with no boost source going to the actuator, if you can't get over 5psi then it's the actuator.
#10
Well an MBC is a simple device, unless the spring is bad/crappy, or it's a poor design, then I can't see it being a "bad" MBC. They don't just go bad or have "bad batches." Does it have a bleeder so that the wastegate can close when you go off boost?
My thoughts are that the wastegate is blowing open. Do a run with no boost source going to the actuator, if you can't get over 5psi then it's the actuator.
My thoughts are that the wastegate is blowing open. Do a run with no boost source going to the actuator, if you can't get over 5psi then it's the actuator.
#11
If this is a homemade MBC then I could see it just being a crap MBC. There is a science behind choosing the correct spring. Too loose and it'll bind and get stuck, too tight and you'll have no resolution in your adjustment. If it's a good MBC, assembled correctly, and hooked up right, then I don't see how it could just fail. It makes no sense. He must have put it together wrong or just got a poor design. Crap MBC? Yes. Improperly installed/assembled MBC? Yes. MBC failure? Not a ******* chance.
Bad wastegate actuator my have been poorly concieved but random MBC failure is just as dumb.
Bad wastegate actuator my have been poorly concieved but random MBC failure is just as dumb.
Last edited by jwarriner; 05-05-2007 at 04:17 PM.
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