Originally Posted by Jordan Y.

Is that Golf a flex-fuel vehicle? You can't just dump E85 in the tank like 100 unleaded and crank the boost on a normal car. You have to completely retune the vehicle, and you'd better have some serious excess fuel injector and pump capacity. E85 stoich is way richer than gas- unless that stock ecu runs off a lambda sensor (which it might) and your injectors and pump are way oversized, and the stock computer is able to adjust and dump a lot more fuel- you're going to run incredibly lean.