Wilwoods or Brembos on 818 without brake booster

[Xusia]

Before you install the pedal box, you drill a new hole for the brake push rod. Since it's closer to the pivot, this results in additional leverage at the pedal. You should be fine!

[Boog]

I was also curious about using brembos without the booster. You could always go with an aftermarket replacement master cylinder of a smaller diameter if too much pedal force is needed, or a larger diameter if not enough fluid is being moved to clamp. Example:https://www.chasebays.com/product/su...ter-eliminator

I'm not sure of the accuracy, but I ran across this post which lists MC sizes http://legacygt.com/forums/showpost....99&postcount=5