Frequently Asked Questions.

For FAQ suggestions, contact- tech@joepmbc.com

Q- What is the "Dual Ball Design" and how does it work?

A- A typical "ball and spring" type MBC uses a single ball that is held against it's seat by a spring. Typically, an adjusting screw is used directly against the spring in order to adjust the spring pressure against the check ball, which in turn increases or decreases boost. The downsides to this are 1) You have no overboost protection in case of adjusting screw loss due to the boost pressure leaking out the hole where the screw was instead of going to the wastegate and 2) in some cases, the end of the spring will actually "catch" on the adjusting screw as you are turning it, causing the spring to bind which will in turn give you inconsistent boost control.

The Dual Ball Design of the Joe P. MBC utilizes the same ball and spring design however, a second ball is added in between the adjusting screw and spring. This gives you the benefits of having overboost protection in case of adjusting screw loss by having a second check ball to block the adjusting screw opening in case or loss AND it prevents spring bind by giving both the adjusting screw and spring a perfectly smooth surface to rotate freely against.
"Joe P. is the innovator of the Dual Ball Design"

Q- I have heard that a Joe P. MBC will give me faster spool up, but I want to keep my stock boost, can I use a Joe P. MBC to only increase spool?

A- No, you cannot simply adjust spool without increasing boost. Also, bear in mind that ANY MBC will create a slight restriction in the wastegate line, which will cause boost to increase slightly even if the MBC is fully open.
Q- How high can I set my boost using a Joe P. MBC?

A- There is no answer to this question. The Joe P. MBC will basically allow for infinite boost increase (as high as your turbo will go), however different vehicles have different "safe" limits.

For those running "high boost" applications, the Joe P. MBC has been tested to 32 psi reliably with more to go.
Q- What tools are needed to adjust my Joe P. MBC?

A- NO TOOLS are required to adjust the Joe P. MBC "XZ" model. The original style Joe P. MBC requires a 3/32" allen wrench (which is included) for the adjusting screw and a 3/8 wrench for the lock nut.

"Easy and reliable boost control"

As always- If you have any questions regarding a Joe P. MBC that is not answered here, contact me at- tech@joepmbc.com