Ebay GT45 + 5.9 Magnum + E85 blow thru

Ok looked back in your thread and if your fpr is still connected by vacuum to the throttle body you need to change that. The boost reference should be coming from your carb hat directly to the fpr.


There's 0 difference to the amount of boost getting to the fpr at WOT if the fpr vac line is connected to the intake, throttle body, carb hat or turbo.
Big difference out of boost, but that's not the issue.