How much compression?
tolerable is subjective depending on the person. I've heard of people running 13/14:1 on E85. But it all depends on the tune, and the consistency in the grade of E85 you run. E85 grade ranges wildly between the time of year and supplier to supplier. Paired with that, at some point you will reach a level of diminishing returns when your tuner ends up pulling timing out in favor of the tune tolerating more compression safely.
Static compression is not nearly as important as dynamic compression. Even with e-85, you don't really want Dynamic compression much higher than 8.5:1. On regular pump gas, not much higher than 8.0:1, and probably closer to 7.8:1 if you drive in hot weather.
http://www.wallaceracing.com/dynamic-cr.php
http://kennedysdynotune.com/dynamic-compression-ratio/
http://www.wallaceracing.com/dynamic-cr.php
http://kennedysdynotune.com/dynamic-compression-ratio/
Yet for a race only engine e85 can work for a much higher static C/R like 14:1 ? Just wanted to know more about that because I'm planning a 416 with slight dome (3cc) and wanted to know if e85 would work with that.
Last edited by 64post; Feb 25, 2017 at 08:53 AM.





