GrimmSpeed Mazdaspeed Electronic Boost Controller - Manual (Page 8)

G
rimm
s
peed 8
A 3-port solenoid does away with the bleed-based system, explicitly shunting air from the
compressor to the wastegate, or compressor to vent (or back into the intake, OEM-style).
Drawbacks of the bleed-based system are thus eliminated, with the wastegate seeing literally
no pressure when the solenoid is energized, to seeing all of the compressor pressure when the
solenoid is de-energized.
Now able to explicitly control the opening and closing of the wastegate, the ECU is able to
control boost with greater precision and reduced response time.
Note! You must tune for this
hardware in 3 port mode! Using stock or off-the-shelf EM with a 3-port solenoid installed in
interrupt mode will result in overboosting!
Figure 1: Pneumatic schematic for the GrimmSpeed
Boost Control Solenoid in 3-port operation
Installation for MazdaSpeed3:
1. Follow 2-port installation instruction 1-9 starting on page 3.
2. Hook up vacuum lines. Port 3 connects to a high pressure boost source. Remove bottom
6mm vacuum line on wastegate. Cap bottom wastegate fitting with 6mm cap. On the
unplugged 6mm vacuum line, push in 6mm to 4mm connector. Connect 4mm vacuum line
from this connector to Port 3 on the BCS.