[raannathr333]

Came across a few articles on blending E85 & 91 octane as well as the below calculator. Given I’m in CA; it’s either 91 or 100 race fuel at $10+ a gallon.

Or, blending E85 & 91.

Blended 4.5 Gallons of E85 & 16.5 gallons of 91; for a blended octane of 94.1 Octane or E27.

In the future, I intend to blend 5.5 Gallons of E85 & 15.5 91 for a blended octane of 94.7 or E30.

Cheaper way to improve power and mileage? So far, was able to run Map 7 on the Dinantronics X (suggests 93octane +) with no issues, knock, rough idle, etc.

Thoughts?

Fuel Mix Calculator

[Planoser]

21 Gallons ??

[raannathr333]

Originally Posted by Planoser

21 Gallons ??

Fuel Capacity for my whip is 21.9 gallons.

[Planoser]

Originally Posted by raannathr333

Fuel Capacity for my whip is 21.9 gallons.

Ahh, didn’t realize you were rockin the x5 👍

[Planoser]

I would highly recommend an ethanol content analyzer. I started by mathing my e-content, even got a tester but quickly found inconsistency at my local pumps.

After installing the fuel-it, I now get real time readings which takes some of the guess work out and gives reassurance I have the right mix.

[raannathr333]

Originally Posted by Planoser

I would highly recommend an ethanol content analyzer. I started by mathing my e-content, even got a tester but quickly found inconsistency at my local pumps.

After installing the fuel-it, I now get real time readings which takes some of the guess work out and gives reassurance I have the right mix.

Good looking out. I’ll get one of these on order.

Yep, x5. Bummed they didn’t provide an x40i platform with the more powerful B58 found in the M340i & M440is. Would have opted for that engine platform.

[mike@x-ph.com]

Originally Posted by raannathr333

So far, was able to run Map 7 on the Dinantronics X (suggests 93octane +) with no issues, knock, rough idle, etc.

How are you checking this since Dinantronics does not datalog?

[Jnasratyar]

Just a heads up, there’s not set ratio of 91 and e to make a certain blend. You have to test the e level of the e85 your pumping and input that into the calculator. Your suppose to test the 91 too, but I’m too lazy for that. I’d reccomend a flex fuel sensor if you ever get tuned.

[mike@x-ph.com]

Originally Posted by Jnasratyar

Just a heads up, there’s not set ratio of 91 and e to make a certain blend. You have to test the e level of the e85 your pumping and input that into the calculator. Your suppose to test the 91 too, but I’m too lazy for that. I’d reccomend a flex fuel sensor if you ever get tuned.

+1

in my opinion a flex fuel kit is a must when blending E85

if the car is using a piggyback, get the Fuel-it kit

if you are tuned with bootmod3, get the PTF flex fuel kit which allows bootmod3 to automatically adjust your map based off the E85 content.

[RTPenland]

gents the analyzers are great tools i love mine but don't get scared - figure out your ratio based on your local pump gas and e85 pump gas ratio of E and enjoy - a properly designed flash will give you alot of safe wiggle room in terms of e content typically as long as it doesn't exceed e50 - we were all doing just fine before these analyzers (although they are a great tool). And remember without additional fueling we really hit the limits of power gain somewhere between e30 and e50.

As an example mission and dinan offers a 100% e85 tune on an otherwise stock car and while it makes more power than stock it does not exceed the power delivered by an an e30 tune (again on an otherwise stock car) so its likely for the person that wants to enjoy the savings at the pump with a little power bump

[aleph-one]

Originally Posted by RTPenland

As an example mission and dinan offers a 100% e85 tune on an otherwise stock car and while it makes more power than stock it does not exceed the power delivered by an an e30 tune (again on an otherwise stock car) so its likely for the person that wants to enjoy the savings at the pump with a little power bump

Always been a curiosity of mine, anyone know why this is the case? Is it a hardware issue, or something about the energy density of petrol vs ethanol? Seems like there's always a sweet spot blend before power gains become diminishing or decrease flat out at a certain volume of e

Edit: To clarify, I know stock fueling tops out around e50. Even cars with full fueling setups tend to run blends as opposed to full e85

[raannathr333]

Originally Posted by aleph-one

Always been a curiosity of mine, anyone know why this is the case? Is it a hardware issue, or something about the energy density of petrol vs ethanol? Seems like there's always a sweet spot blend before power gains become diminishing or decrease flat out at a certain volume of e

Edit: To clarify, I know stock fueling tops out around e50. Even cars with full fueling setups tend to run blends as opposed to full e85

I believe it has to do with the amount of gas needed to burn (at higher temps) as ethanol content increases. The higher the ethanol, the higher the flashpoint = more gas needed; is my novice understanding. This is also why a HPFP upgrade is required…. Requires much more fuel into the cylinder. Again, just my novice understanding. Not science based… moreso broscience.

I’ve heard a lot of the same feedback in other articles… E30 to E50 max seems to be a point where diminishing returns start to be realized.