KTuner.com

If I have ID1ks and actually have to reduce psi the higher the E content can I put negative (whole #'s in as "-3.1") when I save an re upload it comes back as a rounded super high number like 125.556 etc. (and looks to be a positive number) in that cell.

I'm sorry, what you're saying doesn't make from a tuning aspect so you will definitely need to elaborate. There should be no negative PSI adjustments on a properly tuned platform with flex fuel.

So on pump 91 I'm running around 15 psi with anywhere from 2%-10% ethanol at around 75ish injector duty cycle. But when I pump E85 in I need to subtract boost so my injectors don't max.

Change your base target. Add more to the lower end of the ethanol spectrum and add less, or 0, to the high end.

Thank you!