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boost controller ineffective?

aight, i did do a search, but i guess i used bad keywords, or this is a new problem, but pretty much, i put a new boost controller in, one that actually has adjustment to it... i hooked it up exactly how the old "boost controller" (a brass elbow joint with bar fittings on it) and set it about halfway... went on a run, it boosted same as with the old controller, so i set it out a little bit (supposed to raise the boost), didn't change the boost a bit, set it all the way out, didn't change the boost one bit... i'm assuming the vacuum lines it's hooked into are NOT the ones they're supposed to be, and i have no idea which ones it's supposed to be hooked into, this is my first mitsu i've ever really looked at... which lines is the controller supposed to tap into?
 

prove_it

Well-known member
Joined
Jul 3, 2008
Messages
4,201
Location
Sioux Falls, SD
Boost source from the manifold, tee into the line going to the blow off valve and that goes into the source port on the controller, next from the controller the outlet goes to the wastegate actuator. and your done.
 

What boost are you running it at where it is not changing?
Had you ever had it higher?
What do you have for BOV?
What turbo?
 

CarRacer

Well-known member
Joined
Jun 28, 2007
Messages
4,371
Location
Shakopee, MN
I bet there's a few boost leaks in your car. The above information would be really helpful in diagnosing your problem though.

P.S. The search is a little wonky here, but if you add a "+" in front of the words it really helps. Searching for boost controller would look like +boost +controller.
 
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Hertz

Staff member
Joined
Jul 29, 2002
Messages
13,501
Location
Chicago, IL
Quoting mikewitdaspike:
set it all the way out, didn't change the boost one bit...



Well, in = more, out = less... but you can't do less than the wastegate spring or about 10lbs IIRC.

I found it useful to envision what is happening inside the controller... the knob is compressing a spring that has a check ball on the end of it. Your pressure source is pushing against that ball and when it pushes past the spring, it opens the wastegate (stopping the rise of pressure). So the screw/spring/ball is pointing straight towards the turbo. The relief side is usually pointing down and goes towards the wastegate.
 

ohhhh the guy i was talkin to today said that my boost controller was like, in is less, out is more? idk, i'll get a pic tomorrow, and i'll try screwing it in farther (started it about halfway out)... running stock 14b, consistently spikes to 10psi, then drops to 8psi... no boost leaks that i know of

EDIT: never had it higher, and BOV is whatever came in the car stock
 
Last edited by a moderator:

Most boost controllers work by compressing a spring that is pressing on a check ball. The further in you turn it, the more pressure against the ball, so the higher the boost has to raise before it will crack open and release the pressure.
 

gotcha... got it sorted today, it's set at 12psi... if i floor it, it goes up to 12 and holds, doesn't go down, which i guess means no leak? /ubbthreads/images/graemlins/dunno.gif either way, i like the extra 4 or so psi /ubbthreads/images/graemlins/laugh.gif boost feels stronger throughout the boost range, too, even at lower boost
 

boosted_85

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Joined
Apr 2, 2009
Messages
198
Location
milwaukee, wi
That's good that you got things sorted out, don't get boost happy now. Remember to do all maintence and supporting mods before going any higher
 

Hertz

Staff member
Joined
Jul 29, 2002
Messages
13,501
Location
Chicago, IL
Quoting mikewitdaspike:
it goes up to 12 and holds, doesn't go down, which i guess means no leak?



You would think, but no, that's not always the case... it just means that the turbo can produce enough volume to overcome any leaks.
 

Yes - even if it holds boost you still should do a boost leak test.
It will be difficult - if not impossible to get a real good tune if you have boost leaks.
 

where would i get a boost leak test done? and don't worry, i'm not turning up boost until i at least have bigger injectors and a tune to match
 
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