Hello,


I'm alittle confused about a connection mentioned in http://au.geocities.com/ozbrick850/engine-turbo-keithspage.html#manboostcntrl
In the section where it explains to connect MBC1 in line from the ECU controlled solenoid valve to the wastegate actuator., Then for MBC2 in line from the turbo boost output to the wastegate actuator. Now, how can there be two connections to the same location? To my knowledge there's only one inlet nipple on the wastegate actuator, correct? Can anyone explain this for me, maybe I'm miss reading it.
I've copied & paste it below:

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There are many articles on the internet discussing boost controllers but there has been little thought as to how these Boost Controllers can be used to set the desired boost and eliminate spiking yet still retain ECU control over boost pressure.

The answer is to use two MBC’s.

MBC1 is placed in the line from the ECU controlled solenoid valve to the wastegate actuator. It is set to open at the desired maximum boost e.g. 12 psi. However the ECU can still close the wastegate by pulsing the solenoid valve open and applying boost pressure to the actuator.

MBC2 is placed in a line from the turbocharger boost output to the wastegate actuator – bypassing the solenoid valve. It’s function is to eliminate spiking - it is set to a slightly higher pressure than MBC1 - e.g. 13-14 psi.

All hoses between the various valves and actuators must be kept as short as possible for best reaction time to spiking. The MBC valves should therefore be mounted close to the wastegate actuator and solenoid valve. The “baseline” value of the wastegate setting should be left at the original stock position for quickest reaction time - there is no longer any point to adjusting the wastegate rod.

For those whose car may be used by the family on shopping trips you might like to “tame” the car a little by using an extra solenoid valve to bypass MBC2 allowing boost pressure directly to the wastegate actuator. This will limit the boost to the “baseline” value of 3 – 4 psi and the car will become less aggressive. A High/Low Boost switch in the passenger cabin allows a switch between the two modes of operation. It may be possible to operate the solenoid valve from the “Normal/Sport” transmission switch, [easy if this switches 12 volts] but I have not yet investigated this. If this can be done it would be a nice touch.

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Thanxs in advance