COBB TUNING

COBB TUNING
TM
Guide to Boost control system changes
needed for Stage 2 COBB mapping for Mitsubishi EVOX GSR and MR
The stock boost control system in the Mitsubishi EVOX is designed to provide a
mechanical limitation to manifold pressure. In order to achieve optimal boost
pressures for stage 2 Cobb AccessPORT mapping it is necessary to make one simple and
easy to execute change to this stock system.
The stock boost control consists of a series of vacuum lines and two electronic
solenoids. These devices regulate the pressurized air that flows toward the
wastegate actuator. Pressurized air that is allowed to enter the wategate actuator
will open the wastegate and reduce boost pressure. The factory boost control system
works by diverting air away from the wastegate via two electronic solenoids. The
overall quantity of air that enters the boost control system and each wastegate
solenoid is determined by a series of brass air restrictor “pills”. These
restrictors have a very specific diameter to precisely limit airflow.
Two examples
of restrictor
pills
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In order to achieve stage 2 boost levels you will need to remove one of the three
restrictor pills in the stock boost system. The pill to be removed is located just
before the upper wastegate solenoid. The wastegate solenoids are located in front of
the firewall just to the side of the factory blow off valve.
Wastegate
Solenoids
This closer view of the wastegates shows the two stacked solenoids. The restrictor to
be removed is located in the small piece of vacuum tubing just before the most
accessible solenoid.
Remove restrictor
pill from this line at
the uppermost
wastegate solenoid
Copyright © 2009 Cobb Tuning Products, LLC All Rights Reserved.
Pull off this piece of vacuum line and use a long thin hex key or similar object to
press out the restrictor pill.
Reinstall this line without the pill.
You are now ready to run COBB Stage 2 mapping to its full potential.
Copyright © 2009 Cobb Tuning Products, LLC All Rights Reserved.