I think the WG begins to open the bypass valve around 10-12 psi in an attempt to limit max boost to around 16-17 psi in stock tune. I've seen some stock trucks make around 18 psi but not much more than that. With the hundreds of different stock PCM calibrations out there....it seems reasonable that some programs might allow increased boost levels for whatever reason.

I have the Banks Big Head waste gate on one truck and it seems like it remains closed much longer than the stock unit and then eventually dumps boost all at once. Kinda seems like that would be more harmful to the turbo than the OEM wastegate that opens the valve more progressively. However, the engine builds boost much quicker with the Big Head compared to the OEM unit so I guess it performs as advertised. I am just not sure it makes any more usable power on a stock calibration. I'll see if things change once I get some custom calibrations for that truck.

EDIT: I just saw your other post about the 5 psi initial opening point. Makes sense that adjusting it to open at a higher PSI would allow boost to build faster...Seems much cheaper (and probably more effective) than the Banks Big Head. The more I learn about the Banks performance products, the more I appreciate the OEM stuff...

 

Greg,

Our posts are so close together I bet you didn't see my last post.