2 stage question.

[Moparbishi]

on a mid 90's aerostar in the evap system there is a evap pressure control selinoid. this selinoid is desined so when the car sends a 12 volt to one side it opens the vacum source on it. it lookmsalmost like a brake booster HVAC check valve with wires on it.

basicly you can blow through it when it has power but with no power you cant. i run a MBC set at about 14 PSI and as you all know when yourt at partial throttle you will hit full boost above 3k.

so my question is can i set this selinoid inline on the wastegate side with a switch so when it has power the mbc will be used and when it dont have power the waste gate will see now boost signal so it will run at 4. or is this wrong and it will max it self out. i cant handle another 23psi spike.

[tkelly27]

Yes, you can set it up like that, but not quite the way you've described. It will max itself out, if you have it inline and ou have the switch shut off it will render it un-blow-through-able, so the WG will see nada. If you want to use that solenoid you basically have to set it setup like a MBC bypass. Take 1 tee from the compressor outlet (or whichever boost source you are using) send one side to the MBC and one to the solenoid, then have a 2nd tee taking the outlets from both and sending them to the WG. When the power is on, the solenoid will open and you get 4psi. If you are concerned about overboosting you should use a setup from a TD with the 3 barbs and have a boost switch so that over X psi it will flip the barb outlets and run you back to low boost, and you can have it setup in the case that the electricity gets cut off you'll be in 4psi mode 'till you hook it back up. Easy to set up, if you need a picture I can try and draw one for you.