Boost Control With Mac Solenoids On Gtr Twin Turbo Setups

[linkems]

hey guys

I have a blitz dual sbc spec r which is holding boost fine but i want to change to a mac valve for the added functions when paired up with the ecu. I've read a lot of mixed opinions about the typical mac valve 3 port 35A-AAA-DDBA-1BA especially them being bad on TT setups. For the guys that have had success

1.What frequency is your valve set to?

2.What boost are you running with the the boost controller off and actuator spring on it's own?

3.What is your high boost and duty cycle set to?

4.Does the valve get noisy? did you mount it with a rubber insulator?

also is any one running a dual solenoid setup like this? Any problems?

Edited July 27, 2012 by linkems

[portaz]

Old thread but would like to know also

[scotty nm35]

Why would you need two solenoids anyway? Can't you just run the outlet to both actuators?

[portaz]

That was my plan but during searching the subject I thought it worth checking

[rob82]

As has been said, you should only run one MAC valve(running two relies on the valves flowing and responding electrically the same) - unless of course your ECM is capable of twin boost control (sm4) and you can monitor exh back pressure side to side and balance the turbos that way...

As for your questions

1. The minimum requested on time of the valve should not be less than the valve dead time, if fact I would stay a whole factor of 10 away from that. It's really irrelevant but start with around 20hz. What is of more importance when running a closed loop boost control is the feedback frequency. Depending upon you ecu's capability 30hz is a nice feedback rate.

2. What you really need to sort out is what the minimum boost your willing to run vs the maximum boost. For a single sided actuator I would not recommend running over twice the gate pressure unless you have a very competent boost controller. So if you want to run 30psi on high boost then the minimum act pressure I would run is 15psi to have the best of both worlds...

3. Everyone is going to have a different number here as it will depend on the car.

4. Yes rubber mount where possible they can vibrate a bit.