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Discussion Starter #1
so i did an oil change last night, and figured i might as well test some other things while i had the free time. One of the things i did was a boost leak test, changed some connectors and clamps, but during the tests, i realized i didnt see the wastegate actuator moving. My buddies dodge moves under 7psi, but i had mine pressurised to 22 psi, and i didnt see it moving. Turbo doesnt seem to be over boosting, im not running lean, how come the actuator isnt moving like it should?
 

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Exactly where were you appliying your pressure of 22psi? If direct to the actuator nipple, then you shoudl see the arm move that controsl the wastgate....
 

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Discussion Starter #3
had it hooked up just after the turbo, right before the intercooler. but ive done other cars before from the same location, and the actuator will move. Especially at 22 psi. Is there a better place to test to see if the actuator is working?
 

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are you using vacuum + or -? should move when applying positive (like blowing into the actuator nipple - not youself physically of course :D)

if your applying negative vacuum then it wont budge, because youd be sucking it and it cant move any further cos its already shut.
 

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You need to disconect the hose that goes to the actuator and pressurise there. Autos should move at 5psi and manuals at 7psi.
 

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just a quick question how do you do a boost leak test?

Cheers


Chris
 

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are you using vacuum + or -? should move when applying positive (like blowing into the actuator nipple - not youself physically of course :D)

if your applying negative vacuum then it wont budge, because youd be sucking it and it cant move any further cos its already shut.
Most actuators are designed work off a vacuum ie sucking.
A positive pressure can cause damage to the actuator.
 

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Discussion Starter #8 (Edited)
easiest way is to go to a plumbing store, and make one yourself. i just bought all the parts and assembled them for about $15 CAD. simply hooks on to the intake piping, and the other end runs to an air compressor. its basically a valve stem from a tire that leads to a larger 2.5" (63.5mm) outlet to hook onto the intake. you pump some air into the system like filling a tire too, then go look at your boost guage to see if the pressure starts to fall. If it does you have a leak. to find the leak, you can listen and feel for big leaks. small leaks, take alot of time and some soap and water to find.

And i was applying positive pressure (as sexy as my car is, i wasnt blowing it myslef :nono: it was from a compressor). But i need to fit it to the actuator nipple? it wont move applying the pressure anywhere else in the system? ive never encountered that before.

And if someone can tell me what end to fit to, and if i apply + or - pressure to just test the actuator, that would be great. I'm not really worried about the actuator not working, im just really curious now as to why she doesnt budge when the intake is charged to 22psi (1.5 bar)
 

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Most actuators are designed work off a vacuum ie sucking.
A positive pressure can cause damage to the actuator.

Yeah im not doubting this - but, on the pipe that leads to the intake manifold, the nipple on my R33GTST blows air out into the actuator. (obviously it goes into the solenoid first - originally (oem) T pieced so one line goes to the solenoid then another to the actuator. afaik this is so it can do the 2 stage boost thing.

Since the engine/turbo wont be running, the actuator swing gate (wastegate) will be closed, if you apply - vacuum nothing will happen because it cant close any further. with + vacuum it should open unless the actuator is faulty or somethings gotten too hot and welded itself shut (which i dont think can happen in this case?)

theres an easy method to test if there is positive or neg vacuum, disconnect the hose and place it near your ear (sounds bizzarre, but i couldnt feel pressure on my finger tips) rev the engine slightly and youl feel the pressure increase. negative vacuum is usually stronger so you can feel it with your finger tips and hear the sucking sound. - the engine will idle rough until its blocked/ put back where it came from.
 

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Most actuators are designed work off a vacuum ie sucking.
A positive pressure can cause damage to the actuator.
This is completly wrong. Actuators use positive pressure to open, the whole point of them is to open the wastegate when they reach a certain pressure to stop the turbo overboosting and blowing itself to bits. If they worked off vacuum you would never get any boost as the wastegate would be open all the time which would let exhaust gasses vent past the turbine wheel.
 

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Disconect the actuator pipe and conect a pump onto the actuator where you just took the pipe off (footpump with a gauge works fine). Pump it up and see if it moves, if it isn't working then you will have either no hardly any boost or massive overboosting.
 

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taken from rebuild thread in projects forum

whilst you have the turbos out you can check the shaft for excessive play and also check the actuators

to check the actuators you simply connect a footpump to the actuator and apply pressure, it should start to open at 0.5-0.6 bar and be fully open at about 1.4-1.5, if it has got lazy these readings will be lower, if you have uprated items they will be higher











the turbos dont really need to be off the car to check actuator movement like this....you can also use this method to set up adjustable actuators or manual boost controllers (MBC)
 

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Discussion Starter #15 (Edited)
perfect, i suppose i can install my manual boost controller like you suggested while i check my waste gate tonight.

And ill be sure to blow the nipple, not suck it.

thanks much! :worshippy:
 
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