Mixing up my own E85 Blend. Any issues?

[ScottD]

I do time attack events and track days. So ran all the 93 out of the car and filled with VP racing X85, loaded the new tune and car runs great. However, the VP racing 5 gallon can of X85 is around $60 ($12 per gallon). My local station has flex fuel that I tested. Shows around 70% ethanol. VP racing also has X98 in the 5 gallon metal can. Was think of mixing half pump flex fuel with half X98 to achieve a mix close to E85. Cost would then be around $7 per gallon. Could save me around $300 per track weekend and then would have half the number of those metal cans to take to recycle. Was planning to use the VP plastic 5 gallon jug and fill half with pump flex then half with X98, then fill the car from the plastic Jug. Any issues there? Will the two fuels mix well enough just from the pouring both into the VP jug and then into the car?
I usually put about 5 to 7 gallons into the car for each session or whatever It needs to keep the tank full.
It would be nice to save some money but performance is most important so may not be worth it if the fuels won’t mix properly.
Thanks for your thoughts, comments and suggestions.

 

[byronj]

I suggest using an electric mixer so your shoulder don't get tired from stirring the vats. HA! Other than that I have absolutely no input.

 

[docs302]

I do time attack events and track days. So ran all the 93 out of the car and filled with VP racing X85, loaded the new tune and car runs great. However, the VP racing 5 gallon can of X85 is around $60 ($12 per gallon). My local station has flex fuel that I tested. Shows around 70% ethanol. VP racing also has X98 in the 5 gallon metal can. Was think of mixing half pump flex fuel with half X98 to achieve a mix close to E85. Cost would then be around $7 per gallon. Could save me around $300 per track weekend and then would have half the number of those metal cans to take to recycle. Was planning to use the VP plastic 5 gallon jug and fill half with pump flex then half with X98, then fill the car from the plastic Jug. Any issues there? Will the two fuels mix well enough just from the pouring both into the VP jug and then into the car?
I usually put about 5 to 7 gallons into the car for each session or whatever It needs to keep the tank full.
It would be nice to save some money but performance is most important so may not be worth it if the fuels won’t mix properly.
Thanks for your thoughts, comments and suggestions.

I did something similar this year. I had my new motor tuned for both Sunoco 100 (already in the tank) and then had it drained and tuned for E85. I bought a 52 gallon drum of Sunoco E85R and mixed one gallon with pump E75/E80 to get me close to E85. I tested using the simple graduated cylinder kit with water that you can get on Amazon. My local flex fuel pump was only E60 in the winter but I waited until spring when it was up close to E80. On the dyno the car only made about 16-20 more HP with the E85 but it's a lot cheaper as you noted. Only ran the car a few sessions but it seemed to run just fine with that mix. I would think a tune that isn't super aggressive would leave a little room for error.

 

[ScottD]

I did something similar this year. I had my new motor tuned for both Sunoco 100 (already in the tank) and then had it drained and tuned for E85. I bought a 52 gallon drum of Sunoco E85R and mixed one gallon with pump E75/E80 to get me close to E85. I tested using the simple graduated cylinder kit with water that you can get on Amazon. My local flex fuel pump was only E60 in the winter but I waited until spring when it was up close to E80. On the dyno the car only made about 16-20 more HP with the E85 but it's a lot cheaper as you noted. Only ran the car a few sessions but it seemed to run just fine with that mix. I would think a tune that isn't super aggressive would leave a little room for error.

I’m going to do some testing next weekend at Road Atlanta. Right now my top speed on the back straight is 138mph and a PB lap time of 1.36.86. Hoping the E85 can help bring that top speed up to 142-143mph. We will see. Also will monitor CHT. Main concern in mixing is to get a somewhat homogenous mixture. Wasn’t sure if just pouring both into tank would accomplish the mixing.

 

[JAJ]

I do time attack events and track days. So ran all the 93 out of the car and filled with VP racing X85, loaded the new tune and car runs great. However, the VP racing 5 gallon can of X85 is around $60 ($12 per gallon). My local station has flex fuel that I tested. Shows around 70% ethanol. VP racing also has X98 in the 5 gallon metal can. Was think of mixing half pump flex fuel with half X98 to achieve a mix close to E85. Cost would then be around $7 per gallon. Could save me around $300 per track weekend and then would have half the number of those metal cans to take to recycle. Was planning to use the VP plastic 5 gallon jug and fill half with pump flex then half with X98, then fill the car from the plastic Jug. Any issues there? Will the two fuels mix well enough just from the pouring both into the VP jug and then into the car?
I usually put about 5 to 7 gallons into the car for each session or whatever It needs to keep the tank full.
It would be nice to save some money but performance is most important so may not be worth it if the fuels won’t mix properly.
Thanks for your thoughts, comments and suggestions.

Getting a good mix involves some force when adding fuel. If you're able to put 2.5 gallons of X98 into the 5 gallon container and then top it off with the second 2.5 gallons from a gas-station style fuel pump nozzle, the force of the fuel coming from the pump nozzle into the container will mix the two fuels pretty well. Just pouring it in from a second gas can on the ground isn't as effective. That said, once the fuel's in the car, it'll mix pretty well just from the motion of the car. As far as protecting the engine is concerned, if the tuner did the job right, the ECU has guardrails and it listens for incipient knock and adjusts timing every rotation of the crank, so if a bit of E70 gets into the engine, it'll back off the timing and all will be well at a slightly lower power level.