Hey all, built MSM with an EFR6258 @20psi on it, makes 330 on 93, looking to add some extra, and hear E85 is a bit safer as well. I see FM sells the Continental Flex Fuel sensor, and my MS2e has the ability to run flex fuel as Rev told me, but I know there are a few possible limitations.

Walbro 255lph HP, will it be enough?
FIC 775cc Injectors, probably should step up to 1100cc
Fuel Lines, this is a biggie, do I need to replace them

I also see FM makes a Big Flex Fuel kit which I think has a bunch of things that I could do without like the big fuel rail, FPR.

So Miata friends, what is a basic (yet not ghetto), and relatively reliable way to do this for my situation?

 

My NA was around 370whp and the Walbro 255 wasn't enough, at least with stock lines. It just couldn't hold fuel pressure up top. I upgraded to a DW300 and it worked great for me. You'll definitely need more fuel than 775's can flow as well.

I picked up an NB and have similar power goals to you. I just converted the NB to a return system. I pulled the fuel return hardline off my NA when I parted it out. The line popped right in place on my NB. Some people have done a return with the NB evap line but I wasn't comfortable with the tiny line. Once the hardline was in place it's just a matter of swapping a couple hoses at the tank and engine bay. That will give you the ability to raise fuel pressure if needed and use boost referenced fuel pressure.