Brian McPherson's Projects

Tag: E85

  • A few days pass

    So, two days after having to drain the engine of water it ingested because of A2DOT breaking a water main, the car seems to be ‘happy’ again.

    I unfortunately had to put 93 octane gas into the tank last night because I still don’t know where enough E85 stations are everywhere. I need to make a map or something perhaps. I set the AFR to 12.5 to try to get a decent middle ground for either fill of E85 or 93. I’m still -20 in some of the LTFT cells where more power is made, but it’s only around -7 on average in the cells I’ve tuned the most, so there is quite a bit of work left for me to do on the VEs. I’d much rather be -20 on gas than +20 on E85, however.

    The wideband O2 sensor is supposed to come on Monday. I’m planning on getting the fuel rail tapped this weekend so I can run the fuel all out with the fuel pump. Hopefully this means I’ll have a chance of being able to tune to consistant fuel.

  • First tank impressions

    Well, now that I’ve officially ran down a full tank rather than adding to it when I feel uncomfortable about the availability of E85 on a trip, I can write down some thoughts about it. First off, yes, I saw quite a mileage decrease over 93 octane fuel. This was to be expected. I’m estimating based on how I drove on that last tank that I might have seen around 25 mpg on gas, while I got just a hair over 21 mpg on E85. This equates to a slight savings in $$ over the premium fill. I’m hoping I’ll be able to nearly eliminate the difference once I get the wideband O2 sensor so I can adjust my timing after getting it at stoich.

    As for the changes in the car’s personality? It’s much more responsive prior to the power enrich range when attempting to pass on the freeway. 65-80 in 3rd is practically instantaneous as far as one should be concerned. Cranking idle is a bit rough at first, but I’m fairly sure there’s something in the tune that I’m missing that will improve it. I’d estimate that there is a good additional 10% power under the entire curve over running 93. It’s quite significant.

  • Cobalt SS E85 conversion

    So I’ve had the thought for a few years to convert my car to run on E85 rather than 93 octane fuel. I finally got the ambition to try it out, so I ordered a set of 80#/hr injectors and installed them. I’ve been using my hptuners device to flash and calibrate the car to run more acceptably. So far it definitely seems as though there will be a possibility of increasing the power over the 93 tune.  The wideband O2 sensor I ordered from plx devices will hopefully arrive this week some time, so I’ll be able to tune off the AFR instead of the LTFTs. LTFTs have gotten me a lot closer than my calculated tune was able to do, but there’s still a whole lot of progress to do before I can consider it tuned right. I’m hoping to be able to adjust the base timing table as well, so that can be optimized for fuel efficiency and power. I’ll update with more information as I can.