N54 hybrid turbos overboosting

[miksebik]

Hi,
My friend has a N54, he bought hybrid turbos. I told him to adjust the WG which he did (WG closes at 200mbars). The problem is that the car overboosts like hell, there seems to be no turbo regulation. At half throttle, it goes to 27PSI with target 8PSI (well, the target for this throttle is 0). I can send you logs but all you will see is:
WG=39 for pedal 0-25%
WG=25 for pedal over 25%
There is no other WG value.
while the boost goes around up to 28PSI, depending how the pedal is pushed. For example, with pedal 33% there is 12,5PSI.

My other friend has a theory with the lenght of the rod that connect from actuator to WG.. Do you have any ideas where to start? I do not think that the boost solenoids should be responsible for this. So it looks like the turbos.. but what exactly about them?
Thanks!

 

[iminhell1]

sounds like vacuum lines on solenoid are reversed.

 

[miksebik]

I also got a tip from my tuner, Trebila. That the diods in JB4 motherboard might not be cut. I do not know what version that is.. Anyway two good tip to begin with!

 

[intelligence]

Hi,
My friend has a N54, he bought hybrid turbos. I told him to adjust the WG which he did (WG closes at 200mbars). The problem is that the car overboosts like hell, there seems to be no turbo regulation. At half throttle, it goes to 27PSI with target 8PSI (well, the target for this throttle is 0). I can send you logs but all you will see is:
WG=39 for pedal 0-25%
WG=25 for pedal over 25%
There is no other WG value.
while the boost goes around up to 28PSI, depending how the pedal is pushed. For example, with pedal 33% there is 12,5PSI.

My other friend has a theory with the lenght of the rod that connect from actuator to WG.. Do you have any ideas where to start? I do not think that the boost solenoids should be responsible for this. So it looks like the turbos.. but what exactly about them?
Thanks!

The problem is in the vacuum drive WG, because he cannot lift the plate of the valve itself on the bypass channel (from the moment it was pressed by a vacuum actuator upon request WG = 60%). Due to the large amount of exhaust gases pressing on the valve disc, the pressure of which the vacuum actuator cannot cope with, under the influence of atmospheric pressure (operating in the positive period of Duty Cycle N75).
The problem is solved by installing two three-port MAC valves. Two ports are connected according to the original valve (Vac and Out), and the third port is connected to the discharge (either to the manifold or before the throttle, depending on the performance of the turbines).
This solves the issue of efficient reverse motion of the WG drive against exhaust gases.