How do they do it on the VAG engine?
I have zero technical knowledge on the subject but I know when I upgraded the HPFP in my S3 the mid range was where it benfitted the most.

Let's keep in mind he's running 100%, non-diluted E85 without Meth. So the Vargas HPFP upgrade might be sufficient for petroleum based fuels (Pump/Race Gas), it might not be enough for 100% E85.

That is the fifty thousand dollar question, why at my 450-469 (depending on conditions) hp rating am I not able to keep up with fuel demand. I am trying to avoid the whole kill it with meth idea since I have had little luck keeping my meth setup functional for more than a few weeks at a time. That coupled with the fact that I decided to bite the bullet and pay for every known (at the time)fueling upgrade available to future proof my car when I inevitably decide go stage 2/3. Instead I have hit a wall on stock turbos, limp modes every time I go WOT when the tank is full of e85. Check logs and low and behold, 5-600 psi reading on JB4 logs. This triggers an immediate limp mode that makes my car totally impotent. Maybe meth is the answer, maybe this new pump solution terry is looking into is the key or maybe undercover will crack the problem with their idea...All I know is that several thousands later I still cannot run an e85 tune that the car is happy with. Moral of the story for those listening, just buy upgraded turbos and work from there.

Everything is on hold, HPFP (upgraded) is still falling flat on its face (badly) in the midrange. Undercover is going to try some new tactics to solve the issues at hand. I am sad to say that consistently running 100% e85 even on stock turbos is not possible with any hardware out there currently. I know there have been a few anomalies out there (wedge, ect) who have been able to run 100%e85 with no issues but I believe most (if not all of them) are funneling a ton of meth in there to keep things happy. Stay tuned as Undercover tries to get this fuel situation in order.