Need help with actuator/wastegate

[Darrenb10]

Hey guys, ive recently bought my first ford. A bf xr6t my first turbo car aswell. Im goimg im for a tune in a few weeks. Im having a bit of trouble understanding the actuator, lets just say if I buy 15psi actuator will that only allow me to go to 15psi or is the minimum boost 15psi? 

[Puffwagon]

Click me.

[Ralph Wiggum]

Yes

 

and 

 

 

No

 

 

The rating on the actuator is technically the minimum boost you can run. However this rule of thumb assumes the wastegate is capable of flowing enough to support the base boost pressure.

 

If you install and properly setup a 15lb actuator on a stock turbine housing/wastegate port it WILL over boost as the wastegate will not flow enough to bypass suffcient exhaust gas pressure if opening from 15lb.

 

Rule of thumb #2 is you should run a wastegate base spring pressure of aprox 1/2 your desired boost pressure. Again this assumes sufficient wastegate efficiency, but this may not give you the best turbo response. So a well ported wastegate (or external gate) and slightly higher than 1/2 spring rate will give you better response but also flow enough to control boost.

 

All of the above assumes your intake and exhaust are also up to the task, so without know current mods/setup and what you're planning it difficult to give a definitive answer. 

[Darrenb10]

Cheers mate, ive got plazmaman intake and cooler and will get an exhaust soon, I want about 13 or 14 psi so thanks ill keep that in mind

[JETURBO]

You'll want a genuine Garrett 8psi actuator to do that with a good pprt and flapper job