[Sivik]

do you have a mech boost gauge? on your SAFC, whats the boost scale setting? it might be set to read only vacuum, on mine i had to change the pressure scale to read up to 1.0 bar for it so show positive boost.

i would say its a boost leak... fuel won't affect boost pressure (fuel doesn't drive turbo). but it would have to be a big boost leak for no boost to show up.

piping size would be the 2nd thing i look at, but even with small pipes you should get boost pressure just real slow boost build.