E85 and Supercharger? (1 Viewer)

[FJ60GatewayDrug]

Hey, looking for some advice. Is it possible to run E85 in a supercharged V6 4Runner?

For context, the previous owner upgraded the fuel pump and injectors in this truck. I don't have any pinging under any condition, so I'm assuming he did it right. With 91 octane hovering around $4/gallon and E85 less than $2.50/gallon, it's pretty attractive to run even a 50/50 mix. I haven't been able to find anyone else who has done this. If anything, the higher octane of E85 should be safer, but only if I can deliver enough fuel to compensate. The bigger injectors and pump might be enough to do that... thoughts?

 

[cruiserdan]

I wouldn't.

As an aside, for what it may be worth, when superchargers were still available from TRD for the 5.7 V8 they specifically excluded the flex-fuel engines.

 

[FJ60GatewayDrug]

Hey Dan!

I found that in my research, too. But some threads (like this one: E85 TRD Supercharger? - Toyota Tundra Forums : Tundra Solutions Forum) made me wonder if it is doable. Mostly talk about ECU tuning and minor corrosion worries. There are reports of flex-fuel vehicles with the supercharger, but only running on standard E10. The stock 5VZ-FE engines run fine on a 50/50 mix and only throw injector duty cycle codes if it gets too much E85 vs. regular gasoline, which is why I started wondering.

Let's say I did want to test this out and go, say, two gallons of E85 in a tank at a time. What would I need to monitor to make sure I'm not going to do expensive damage?

 

[Tigerstripe40]

The supercharger system was engineered to run a specific way with a specific setup. The time, money, and effort that it would take to modify and tune the truck to run E85, you can buy an *aweful* lot of Premium fuel. Plus it won't be as reliable.
I wouldn't bother.

If MPG's and fuel cost is your primary concern, get a Honda Civic, or Motorcycle.

 

[FJ60GatewayDrug]

The supercharger on these was bolt-on and there exists an aftermarket to fix some of it's deficiencies. The URD 7th injector kit being the most famous example, but many people have swapped larger injectors and fuel pumps in to keep up with the supercharger's thirst. I'm not trying to get better MPGs out of a 20 year old SUV, and I knew going into it that if I couldn't afford the premium fuel I couldn't afford the truck.

I didn't do a good job at explaining my ulterior motivation here, sorry! My fingers got ahead of my brain while I was typing quickly at work. I know that in CA we get a maximum of 91 octane vs. 93+ in other parts of the country. E85 has higher octane and burns cooler, both of which should be safer for a forced injection engine; however there's ~25% less energy content in E85 vs. gasoline. With bigger injectors and uprated pump, that 25% deficit could be made up. But with a supercharger pumping ~25% more air into the system, not delivering enough fuel could cause the mixture to lean out, resulting in damage.

If E85 is cheaper, that's a bonus, and being so much cheaper it is hard to ignore it's siren call. But there are other advantages to running E85, even mixed with gasoline, aside from the cost. That's what I'm curious about exploring.