Let me make sure I have this right.

First, the Evo 8 makes 20ish psi max, stock.

Boost lessens (in psi) at higher RPMs.

The fact that it lessens at higher RPMs is something controlled by the ECU.

The only way to retain higher boost to fuel cut-off requires ECU, boost-controller, or both?

When is a BOV truly required?

I don't want a debate here just some simple understanding so I can search what's already here more effectively.

Thanks!

 

You can also remove the boost restrictor pill in the tubing from the stock boost solenoid but that's not recommended.

You'll ultimately need either a boost controller or an XEDE or soon-to-be-released UTEC to modify the stock boost settings.

The BOV is debatable but I believe the stocker will hold pretty much anything the stock turbo will throw at it.