User guide

Grimmspeed

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.

Installation for 2002-2005 WRX and 2004-2005 STI: Remove cover on passenger side engine

bay exposing the factory boost control solenoid. Using a 10mm socket, remove factory

solenoid and unplug the electrical connector and vacuum lines. Reuse the factory rubber

mounts and transfer them to the GrimmSpeed bracket. Install GrimmSpeed bracket and

solenoid while reusing the factory nuts.

Hook up vacuum lines. See Figure 2. Port 3 connects to a high-pressure boost source (there is

a vacuum nipple on the turbo compressor outlet). Port 2 connects to the internal wastegate

actuator vacuum nipple and Port 1 should be routed back to the intake (where the factory

BCS mounts). Remove the factory restrictor pill. It is recommended that a plastic zip tie be

used to secure vacuum lines. The electrical is plug and play with the supplied connector.

Tuning: WGDC controls the actuator / turbo. Tuning to the WGDC is required (approx 30%

reduction in WGDC)

Installation for 2006-2007 WRX and 2006-2007 STI: Remove factory boost control solenoid

bracket on passenger side engine bay using 10mm wrench. Unplug the electrical connector

and vacuum lines. The GrimmSpeed valve will go on the same bracket but in a different

location on the bracket. You will use the two properly spaced holes to mount the

GrimmSpeed valve. Attach using included grommets and hardware using a 10mm socket.

Hook up vacuum lines. See Figure 2. Port 3 connects to a high-pressure boost source (there is

a vacuum nipple on the turbo compressor outlet). Port 2 connects to the internal wastegate

actuator vacuum nipple and Port 1 should be routed back to the intake (where the factory

BCS mounts). Remove the factory restrictor pill. It is recommended that a plastic zip tie be

used to secure vacuum lines. The electrical is plug and play with the supplied connector.

Tuning: WGDC controls the actuator / turbo. Tuning to the WGDC is required (approx 30%

reduction in WGDC)

Installation for 2008+ WRX and 2005+ Legacy GT: For Legacy GTs, remove plastic engine

cover. Remove factory boost control solenoid using a 10mm wrench. It is located on the

passenger side of the intake manifold. Unplug the electrical connector and vacuum lines.

Install GrimmSpeed bracket and solenoid while reusing the factory bolt.