Originally Posted by Mike@N54Tuning.com
No, the JB4 monitors timing advance and fuel trims and auto tunes itself when on E85. So you don't need to monitor anything. To run more than 50% E85 you normally also need the BMS flash which allows higher than OEM advance points and resolves the fuel trims issues.
So would you say running jb4 map 5 is just as good as using the Vishnu flex fuel kit? The one thing I like about jb4 is you don't need to send your dme to get it flashed.