Just don't go to ShaidarHaran's "tuner"
Who says he even tuned it dude probably threw parts on and went full send.
Stock fuel is actually pretty good. The 18's and higher have both direct inject and port injectors. That's good for E85 naturally aspirated without touching the fuel system at all. It is also good for low boost setups on pump gas. The stage 1 kits for Procharger/Vortech/Paxton don't call for injector upgrades for example.
However, high output boosted applications (like Whipple or Procharger Stage 2) or any boosted with E85 will require injector upgrades. E85 especially will need a BAP or fuel pump upgrade as well.
I plan on running a Paxton supercharger kit with E85 later this year. For that I'll be using a Fore fuel system with ID 1050x injectors.
E85 is so good powerwise, it's like running on race fuel all the time. Plus it runs cooler than pump, better for your engine. There's lots of E85 stations around here with quality E85 fuel (that tests actual 80% ethanol and higher), I don't think I want to go back to pump gas for any tune, even boosted.
I would like to go meth injection or flex fuel but like I said, availability near me isn’t that great. The mileage on E85 is another issue. Just not something I could do 24/7. I’d love to do meth injection .. I’m still toying with doing EGR/TGV deletes (helps against carbon buildup on the valves) and then going meth injection to really keep it clean and also get a decent performance boost. I would have to grab a new fuel pump though and injectors would be really close to max duty cycle at WOT. This **** is a massive rabbit hole that I keep falling into lol.
Not sure if the Mustangs have this issue but as with any direct injection motor, make sure you keep an eye on the carbon buildup on the valves. I plan on doing my TGV deletes myself and when I have them off, I have a buddy who has a walnut blaster who can clean the valves for me. I’ve seen pics of people’s valves after only 30k miles and they are COVERED in carbon buildup. Not sure if your motor is susceptible to that since it isn’t a straight up DI system, but just something to keep in mind.
I want meth and I want it now!!!