What Do You Need To Do, To Run E85 In Your Nissan Skyline?

E85 fill up Nissan Skyline GT-R

Ever hear of Chicken Little. The guy that runs around, and yells "The Sky is Falling, the sky is falling"  This is who I think of, when I hear some people talk about things, they have never tried themselves.  E85, or 85% ethanol and 15% gasoline, is a type of fuel.  The 85% ethanol is an "up to" number, where the actual mix can be anything from 51% to about 83%. In cold weather there is more gasoline in the mix, as it is easier to start with more gasoline.  For most cars, you can't just put E85 into the car, and expect it to run right. 

• Alternative Fuels Data Center
• E85 vs Gasoline Edmunds
• EPA E85 Fuel

This Enginelabs article has some great information and results of 93 vs MS109 vs meth injection vs C85. 

The upside is that ethanol does a great job of cooling the combustion process. It "acts" something like 100+ octane fuel.  I just paid $1.85 a gallon for 7.6 gallons, or $14.15 for fuel that more or less acts like race gas.  I normally pay about that per gallon of good gas. So what do you need to do to run this fuel, that you get worse gas mileage, is a little hard to find, and is labeled as a "bio-fuel".  Not much really.  For the Bluecar fuel system, I had:

• Nistune
• ECB-1
• Flex fuel sensor in the return line
• Shows boost, Ethanol percentage, AFR, and fuel temperature
• 1250 cc injectors from Kudos
• Stock fuel pump
• Stock fuel lines at the tank
• Stock fuel pressure regulator

Now that setup, isn't something that I would call ideal, however real life, and ideal don't always intersect.  I had a Hellcat- 525l/hr fuel pump for the car, that I ran out of time to install before the dyno and R's Day.  Rather than take any risks, I figured it probably had a decent fuel pump, and would be enough for the power I wanted to make.  I was wrong.  In my fuel system post, I talk about it being your limiting factor when you dyno, and I proved it there.  At 9 psi on E85 the car did 330 whp.  At 14 psi on E85 it did 440 whp. We tried 19 psi, but ran out of fuel by 500 whp, and about 6000 rpm, so we backed it down to 14 psi, and figured that was enough.  That was on about 70% ethanol, or you could even say - E70.

Ran the car out at R's Day in October. Had a fun day, struggled with a few things with the car, but power wasn't one of them.  After R's Day, I use the Bluecar as a limited Friday, some weekends car. Mostly it sits in the garage.  I don't burn a lot of fuel, and I have heard a lot of horror stories about the fuel sitting.  I did recently replace the fuel pump with a 525 l/hr pump, everything in the tank, lines etc all seemed good.  Nothing out of the ordinary. 

Even when it was $2.89, it was about a dollar cheaper than normal 91 in Southern California. 

The beginning of this month (April 2020), I decided to take the fuel filter out to replace it. Figured if anything really bad was going to show up, now was a good time to check it.  From the supply side, the fuel looked dirty, but honestly about the same as it did, the last time I replaced the filter in the car. 

Fuel filter after running it for about eight months on E85

ECB-1 Mounted in ashtray location for E85 and boost monitoring

Cut the fuel filter open to look at the insides. Disregard the metal shavings this way was fastest

Cut the fuel filter open to look at the insides. Disregard the metal shavings this way was fastest

So my conclusions. Run E85. Do it. Don't look back. 

E85 used to be a little hard to get in SoCal, that was one excuse for a while not to run it. Then having an ECU, flex fuel, tuning it for E85 was the next excuse.  You will get worse gas mileage, which isn't  really a concern.  Not every gas station carries it, which is why you run a flex fuel setup.  E85 is hygroscopic, or it attracts water, you just need to get out and use it every now and then. Run a normal tank of E10(pump gas) through it every now and then, and it should keep everything in the system decently clean.  Like any car, or high performance car, it will require maintenance. I think its a good idea to replace the fuel filter every 6 months or so to monitor the system.   E85 smells great, car runs great. I can crank it up without worrying about the 91 octane fuel in the car. It never gets that cold in SoCal, so I am not worried about the blend or starting. 1250cc injectors idle fine on a RB26, with a Nistune.  Can't wait to get the E85 setups in Big Bird 2, and my Nismo.  Both those cars will be more max effort, none of this weak 14 psi stuff. 

Injector Dynamics thoughts on E85

In the real world, the broad flammability range, excellent cylinder cooling, and outstanding detonation resistance of ethanol make these issues less problematic than the numbers might suggest. But that doesn’t change the fact that injectors get stuck, and engines blow up because of the facts stated above.

How to deal with it? As with most things, knowledge is power. Just knowing that your opponent has a big left hook is half the solution.

1. Do not let your E85 or methanol-powered car sit for extended periods of time. In hot humid weather, the alcohol can absorb enough water to rust injectors in less than a week. If the car is going to sit, “pickle” the fuel system by emptying the tank and flushing the system by running the engine on gasoline for a few minutes.

2. Monitor the ethanol content of your fuel. This can be done one of two ways. Either install a fuel composition sensor, or measure it directly using the “baby bottle method” which is detailed at the end of this article.

3. Tune conservatively. Knowing that the octane value of the fuel can change even if the ethanol content remains constant, you will be wise to leave a few hp on the table by keeping that final 2 degrees of advance to yourself.

4. Eliminate the consistency issues altogether by purchasing “racing” E85 by the drum. Not exactly practical for the average street car, but if you’re racing I wouldn’t even consider running E85 from the pump. In addition to having a consistent ethanol content, E85 from a race fuel blender should insure that the “other hydrocarbons in the gasoline boiling range” used to make up the remaining 15% are of high quality with a reasonable octane rating.

Better yet, buy E98. The car may be a bit hard to start on a cold morning, but it is a race car right?

5. Don’t be stupid. This should cover anything I forgot.

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