Currently i am running a Tial 40mm wastegate, with 8.6psi spring. Generally the spring overboosts to approx 10psi.
I purchased a GM solenoid part #1997152 to control the wastegate
the valve has three connections. Two on one side, one on the opposite side.
The side with one input I will call port 1.
The connection directly across from it is the Normally open, port 2. The 3rd port is a vent.
With no voltage applied, the air flows from 1 to 2. With voltage applied air flows from 2 to 3.
My goal was to connect the boost signal to a normally closed valve, and pwm modulate it when it reached a certain kpa value.
After some bench trials, the best way to do this was to invert the output from VEMS going to the valve. This closes the valve and allows my boost signal to connect to port 1. Port 2 then connected to the bottom side of the wastegate.
config variables
boost_channel=60 # inj G
boost_conf=69 # MAP target, 48Hz, 2/5 opened reference position
boost_targetoffs=00 #not needed for MAP target
boost_minpressure=34 # 104kPa in 2kPa units
1. PID input is in 1/8 kPa units
2. PID output is -2048..2047
boost_pid_kp=26 # Fero's default
boost_pid_ki=40 # Fero's default
boost_pid_kd=10 # Fero's default
boost_pid_ilimit=52 # Fero's default
When i reach a map value of 175, the valve begins to modulate and provides a reduced pressure to wastegate.
Initial trials were promising. No large overshoot, but some oscillation - approx 2psi.