Turning wastegate?
Here is a quote; he is talking about the Forge WGA, but should answer your questions.
Originally Posted by Mike@Forge
As I said earlier, the higher spring pressure within our unit allows for the wastegate flapper to be held closed tighter and for longer against the exhaust gas pressure flowing through the turbo.
With the weaker spring of the stock unit, as well as the poor placement of the wastegate flapper within the exhaust housing, the exhaust gas pressure can easily force the wastegate flapper open prematurely. When this occurs, the exhaust gas that is supposed to be spooling the turbo is dumped which will slow the speed of the compressor wheel and limit the potential to build boost further.
Tightening the stock unit will have the same effect as ours, as many people are finding, but to a much lower degree. You're working with an altogether weaker spring to begin with. Somewhere in the neighborhood of 12-15 PSI base pressure.
We assemble our units with a 19-24 PSI base spring pressure, so the possibility of the exhaust gas pressure prematurely opening the flapper against this higher spring pressure is minimized, if not completely eliminated.
All of the exhaust gas is kept within the exhaust housing of the turbo and is forced to continue spooling the wheels keeping boost at it's peak potential.
A boost controller will still allow you to adjust up from the base actuator spring pressure, and it will open the actuator when the target boost pressure is reached, but with the stock unit, there is still the potential for the exhaust gas pressure to prematurely open the wastegate BEFORE peak boost is reached and the boost controller would send the signal to open the actuator.
With our unit, the boost controller will still function in the same way, sending the pressure signal to the actuator to open it fully when the target boost level is reached, but there is far less chance of the exhaust gas pressure opening the flapper before that occurs.
Depending upon how the units are adjusted, you will see changes like quicker spool, less tapering, and an overall increase in the area under the boost curve. The units are piston based, and fully rebuildable. They carry a lifetime warranty.
With the weaker spring of the stock unit, as well as the poor placement of the wastegate flapper within the exhaust housing, the exhaust gas pressure can easily force the wastegate flapper open prematurely. When this occurs, the exhaust gas that is supposed to be spooling the turbo is dumped which will slow the speed of the compressor wheel and limit the potential to build boost further.
Tightening the stock unit will have the same effect as ours, as many people are finding, but to a much lower degree. You're working with an altogether weaker spring to begin with. Somewhere in the neighborhood of 12-15 PSI base pressure.
We assemble our units with a 19-24 PSI base spring pressure, so the possibility of the exhaust gas pressure prematurely opening the flapper against this higher spring pressure is minimized, if not completely eliminated.
All of the exhaust gas is kept within the exhaust housing of the turbo and is forced to continue spooling the wheels keeping boost at it's peak potential.
A boost controller will still allow you to adjust up from the base actuator spring pressure, and it will open the actuator when the target boost pressure is reached, but with the stock unit, there is still the potential for the exhaust gas pressure to prematurely open the wastegate BEFORE peak boost is reached and the boost controller would send the signal to open the actuator.
With our unit, the boost controller will still function in the same way, sending the pressure signal to the actuator to open it fully when the target boost level is reached, but there is far less chance of the exhaust gas pressure opening the flapper before that occurs.
Depending upon how the units are adjusted, you will see changes like quicker spool, less tapering, and an overall increase in the area under the boost curve. The units are piston based, and fully rebuildable. They carry a lifetime warranty.
