Bill The reason for the limit on the boost has a lot to do with the extreme flow my turbo puts out. The spec on it is 585 cfm @ 2.8 PR or 48 lb/min @ 2.8 PR @ 70 % efficiency( standard day). 2.8 PR equates to about 17-18 psi of boost. 22 psi works out to about 670 cfm @ about 80% efficiency