Forge Actuator Spring Rates


Thought this may be of interest to some, received this from a guy at Forge Motorsport

The following is general information regarding Forge actuator spring tensions and are important considerations when making a decision on which spring you install, especially if you are running a boost controller or planning an ECU upgrade.
The 4 springs we offer are listed below under their relevant colour codes and related pressures. Running pressure is the lowest or minimum pressure the spring will operate at, which is important when considering which spring you choose. The spool up pressure relates to the vacuum pressure required to lift the spring from its static position, at which point the turbo waste-gate will start to open (spool up).
The actual rating for these springs is as follows, the lower pressure being the spool up pressure and the higher pressure being the running pressure:

RED 17 psi (spool up) - 20 psi (running pressure) our product code FMAS049R.

BLUE 14 psi (spool up) - 18 psi (running pressure) our product code FMAS049B.
YELLOW 9 psi (spool up) - 15 psi (running pressure) our product code FMAS049Y.
GREEN 5 psi (spool up) - 10 psi (running pressure) our product code FMAS049G.

The spool up can be altered to a higher pressure by adding more tension to the spring. Be careful not to add too much tension to the spring as it will become coil bound, affecting the rod travel and thus affect the waste-gates ability to open effectively. Running pressure cannot be adjusted by adding pressure to the spring.

Mount the actuator to the actuator bracket on the turbo and wind the turnbuckle into a position 3mm short of the spigot on the waste-gate arm, requiring you to pull the rod into position over the waste-gate spigot.
Do not add more than the recommended tension as this will cause the spring to become coil bound, preventing the waste-gate from opening properly. There is a common misconception that the operating pressure of the spring can be increased by mounting the actuator rod to the waste-gate arm in such a way that the spring is under more load than the recommended above.