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Discussion Starter #1
when the turbo on the jtd gets to full boast, how and where does it bypass the unwanted pressure???


usualy they have a waste gate/ actuator to open a bypass valve on the turbo, but cant seem to see how it works on the variable valve turbo from the jtd

can anyone shed some light on this
 

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On petrol cars there is a butterfly valve that blocks the inlet manifold from the turbo when the throttle is released so pressure has to be dumped. I dont think diesels have one so the pressure is just goes into the engine
 

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The intake guide vanes on the turbo modulate control boost pressure.

There is no dump valve/ wastegate when you use this type of turbo.
 

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Discussion Starter #5
ok if the veins get the pressure to the correct level and no more, how is the boost turned up when remaped????

the veins must get to full high pressure mod at some point even on a standard map
 

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ok if the veins get the pressure to the correct level and no more, how is the boost turned up when remaped????

the veins must get to full high pressure mod at some point even on a standard map
the overboost module/vnt controller behind the front slam panels controls the opening/closing of the veins.
This is an electronic (solonoid) device which does what its told by the ecu.
The ECU monitors the map sensor voltage (which you can trick to up the boost), looks at the map and adjusts the veins ia the overboost module/vnt controller
 
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