Jason@JGY
01-11-2008, 04:24 PM
Contrary to popular belief and many published documents, installing the vacuum/boost lines onto an external wastegate is the same as an internal gate.
Most electronic boost controllers act as a solenoid that stays closed until the desired psi that you want.......at which point it opens and lets boost go to the wastegate.
Many wastegates are a "push" design. By this, I mean that as your car builds boost, that boost goes to the underside of the diaphram on the wastegate and depending on what spring rate you have......it opens at a set amount. Basically, this is the same thing that an internal gate does.
For example, Greddy's published literature and several turbo parts distributors ARE WRONG AND TELL YOU WRONG. They suggest that for an internal gate that the line going to the gate be the "com" port of the solenoid, yet for an external gate, use "com" and put it to the top (above the diapham) of the wastegate and let the bottom part of the wastegate be connected to a generic boost source. The idea behind this is that the Greddy solenoid will keep pressure on the wastegate and PREVENT it from opening until the desired PSI. THIS IS WRONG.
Connect an external gate the same way you do an internal gate. Connect the boost hose from the "com" port of the solenoid to the bottom or side of the Tial Wastegate. Connect the "no" port to a boost source. You are done.
Think of it this way.........the solenoid doesn't know what it is connected to.....internal or external. So connect an external in the directions that Greddy shows for an internal gate and you will be set.
P.S. This have been proven on several installs here including the Mustang.
Most electronic boost controllers act as a solenoid that stays closed until the desired psi that you want.......at which point it opens and lets boost go to the wastegate.
Many wastegates are a "push" design. By this, I mean that as your car builds boost, that boost goes to the underside of the diaphram on the wastegate and depending on what spring rate you have......it opens at a set amount. Basically, this is the same thing that an internal gate does.
For example, Greddy's published literature and several turbo parts distributors ARE WRONG AND TELL YOU WRONG. They suggest that for an internal gate that the line going to the gate be the "com" port of the solenoid, yet for an external gate, use "com" and put it to the top (above the diapham) of the wastegate and let the bottom part of the wastegate be connected to a generic boost source. The idea behind this is that the Greddy solenoid will keep pressure on the wastegate and PREVENT it from opening until the desired PSI. THIS IS WRONG.
Connect an external gate the same way you do an internal gate. Connect the boost hose from the "com" port of the solenoid to the bottom or side of the Tial Wastegate. Connect the "no" port to a boost source. You are done.
Think of it this way.........the solenoid doesn't know what it is connected to.....internal or external. So connect an external in the directions that Greddy shows for an internal gate and you will be set.
P.S. This have been proven on several installs here including the Mustang.