I watched a video on YouTube from Chris Fix about a flex fuel kit and wondered if there was an easy/reversible way to install flex fuel on the C55. Surprisingly, this company had an exact kit for a M113 engine so I ordered it on Tuesday from Finland (yeah, the country). DHL delivered the kit on Friday and I proceeded to start the process which was straightforward. I did not have to cut, splice, or hack any harnesses for the installation. Also, the fuel line was a direct replacement for the braided fuel line which runs from the driver's side to the fuel rail. I promise I will add pics tomorrow.

Before I get too crazy with more explanations, you need to watch the video of an install on a Prius to get the basics of this kit. The fuel system needs a flex fuel sensor and associated wiring so the fueling can be adjusted by the little brain box via an injector harness. The strangest part of the install was pinning the new harness in the correct orientation prior to placing the included harness in line with the factory injector plug. Use a continuity tester to confirm but the + wire is the inboard wire closest the intake. The included harness had the red wire for the injector in the correct location indicating + so that step wasn't really necessary. It is nice to confirm but you will understand when you see the harness.

This kit uses an app to give data realtime injector duty cycle, rpm, speed and ethanol %. You also have three driving modes: economy, dynamic, and sport. There is no real explanation of the driving modes and I don't feel much (if any) difference between them. A data line showing individual injector function is also present to confirm power to each injector. It also has its own fault system if there are any issues. Luckily, I had no faults and it has worked flawlessly for 50 miles or so at 53% ethanol. The kit was $599 and took me maybe 2 hours to install. I think I could do another one in half the time. Any performance difference you ask? It is hard to tell as it was 98°F and humid today so performance testing was not happening. I think the technology is amazing and it has a bypass plug included if for some reason the brain box decides to go kaput. The bypass plug will revert everything to stock injector function if the need arises. Pics tomorrow.

 

 

Cool project, let us know how it goes!

 

What’s the benefit on a normally aspirated car that wasn’t designed to accept ethanol or the increased fuel volume for it? Nothing in that fuel system is designed for that.

 

Our cars are designed to accept ethanol 10% so your statement isn't accurate. They aren't speaking of running 100% ethanol as pumps only have E85 which can vary 71-85% ethanol. The system adjusts the fueling and our pump isn't working much harder to supply fuel. The injectors can handle the extra ethanol and the duty cycle isn't even close maxing out according to the app data. Cheaper fuel, cleaner running, higher octane, and cooling properties are a plus with a little less fuel economy. The C55 hasn't impressed me in the fuel economy department thus far so no biggie with a little less.

 

 

Better put something over that fuel line rubbing on the valve cover, over the exhaust manifolds With as much as the motor mounts move, that looks to be a problem.

 

thanks for the concern; however, there is clearance between the valve cover and the fuel line. The angle of the photo doesn't clearly show the space. Because of your comment I did add some black plastic sheathing to the fuel line.

 

E85 is not available around here so this discussion is new to me. E85 is about 10% cheaper on average per gallon but contains about 30% less energy than gas so car has less range. It appears E85 is a worse value proposition. E85 is cleaner at the pipe but like EV, environmental cost of production is not factored in. The only benefits I see are higher octane and better cooling which with a tune would allow for greater power production.

 

It is a worse value option where I live as well. I used it in a forced induction car and it gummed up the fuel injectors over the winter. It was not a sealed system, and when the ethanol evaporated, it left a sugary goo throughout the system. The e85 stations around here are dwindling, and I am not a fan of it for cars older than 2010.