"Fuel Management Unit" I have one on my car. My 12.6@116 setup is as follows: Vortech 4:1 fmu (raises fuel pressure 4 lbs per pound of boost instead of 1 lb like the stock regulator), Walbro 255, HKS FCD type K3 with dial set to 3, stock injectors, and stock afm. Running 18.5 psi boost with water/air intercooler on 104 octane unleaded. This setup gave me a perfect 12:1 a/f ratio from 3000 rpm all the way to redline. Lower boost levels will cause the engine to run rich under boost as does the stock intercooler because it is sooooo restrictive. Sorry about the blurry pic (the fmu is the blue thing). It is installed after the stock fpr.