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Boost 0.49?

So im a little confused 1025 is all stock and stock boost controller, while driving if i boost to max will read 0.49 kpa which i thought is like 8lbs or less and seems tapped correctly,shouldnt it max at around 10 stock or am i wrong.
 
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Thanks, in your pic I'm not sure where you tapped into. Which line is that?
 

The fpr line should give an accurate reading as long as you tapped off of the side that attaches to the intake manifold. (Assuming that your car is in every way, 100%, as originally intended, STOCK) if you tap off of the line attached directly to the fpr, the vacuum/boost signal is interrupted by the fpr solenoid, which may lead to an inaccurate reading.
 

okay so is correct now why at max would be 0.49 and what is the amount of lbs that is
 

ktmrider

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Yes stock boost is about 11psi ( around 0.75 bar ).

However WG-only boost is about 7psi ( around 0.50 bar ).

Sooo, is your BCS hooked up?!?
 
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yea its hooked up so should work im stumped /ubbthreads/images/graemlins/banghead.gif
 

try check your bov..i think it was leaking...last time my vr4 got the same simptom... /ubbthreads/images/graemlins/smile.gif
 

ktmrider

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Quoting 1025vr4:
yea its hooked up so should work im stumped /ubbthreads/images/graemlins/banghead.gif

Alright now make sure it is working.
Like mentioned it sure sounds like you are running on WG spring pressure, if you can't blow thru the BCS when the car is off it's stuck closed.
 

yes, a boost controller holds the air path shut with a spring until a certain boost level is reached. Then the spring depresses and allows air through which signals the wastegate to open.

It could however be stuck open, in which case it would essentially be doing nothing.... just a glorified vacuum line.
 

belize1334

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Nov 18, 2003
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Bozeman, MT
^^ No. The stock bcs is a bleeder style boost controller. It doesn't interupt the path from the source to the actuator. What it does is open a controlled leak to vent air from the signal which causes a pressure drop in the line and reduces the pressure reading at the actuator. If it's stuck closed, the leak is fully plugged and you get actual pressure at the wg which will cause it to run at about 7psi. Fully open it leaks a little which bumps boost to 11psi. If you remove the little restrictor ring it makes the "leak" bigger which raises the max boost to about 13psi.
 

Okay so ill take it off tomorrow after work and check it out, hopefully that's all it is I hate hidden leaks lol.
 

ktmrider

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Joined
Sep 10, 2007
Messages
3,128
Location
Tempe, AZ
Quoting belize1334:
^^ No. The stock bcs is a bleeder style boost controller. It doesn't interupt the path from the source to the actuator. What it does is open a controlled leak to vent air from the signal which causes a pressure drop in the line and reduces the pressure reading at the actuator. If it's stuck closed, the leak is fully plugged and you get actual pressure at the wg which will cause it to run at about 7psi. Fully open it leaks a little which bumps boost to 11psi. If you remove the little restrictor ring it makes the "leak" bigger which raises the max boost to about 13psi.

Bingo! Let's try not to confuse the OP too much.
Also post up the the WG hose setup, even if the stock BCS is open it could be bypassed or not hooked up properly.
 

My bad, I guess I have never actually taken apart a stock boost controller. Just assumed it was the same design as my hallman...... but I guess you see what happens when I assume things /ubbthreads/images/graemlins/uhh.gif
 
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