DIY E85 How to?
 

Just put flex fuel in a 2018 gti. very easy and simple. But for my Miata I wanna do the same because I won’t have access to 93 anymore. So for a parts list I found some 650cc injectors and the gm flex fuel sensor off fab 9. I know one wire for ground, power, then the one for the ecu. How do I do that? It’s a 1990 on a speedyefi. Do I make a pin like I did for the gti? Or do I have to open the board and solder? Can’t find much online so thought you guys can help. Any videos and pictures are hugely appreciated because I’m a visual learner haha. Thanks!

I was literally poking around to figure out where to do a writeup on how to add flex fuel lol. I guess there is some demand.

pleaseeeee do I need to know

I did a write up which is like 1 post above this one.

I didn't cover running the wires to the ECU. The Speeduino should have a dedicated flex pin which you'd need to get the signal to.