We have found a solution for flex fuel tuning your Subaru that works with the green speed update. Delicious Tuning re-released their V1 flex fuel kits that they had before Cobb came out with the current kits you are used to. We have been tuning with these kits on the 2002-2005 WRX and EVO X with Accessports for many years and tuning flex fuel this way works very well.

No check engine lights, and you get to use your Accessport

These kits function the same as the Cobb kits by sending an ethanol signal to the ECU that we can use to adjust boost, ignition timing, and fueling depending on the current ethanol content. Where these kits differ is they do NOT use the TGV or Rear O2 for the signal input, so it is still compatible with the new green speed update and will NOT throw any check engine lights. You will also not get a direct ethanol gauge on the Accessport like in the past, but can monitor ethanol content via the IAT (Intake Air Temp) gauge. By setting up your Accessport to read in Celsius, the IAT gauge now reads ethanol on a 0-100% ethanol scale.  You can also monitor ethanol content via an app on your smartphone. You can download the android version here and the apple version here.

The Delicious Tuning flex fuel kits cost about the same as the Cobb kits and are currently available for the following models:

  • 2004-2021 STI
  • 2002-2021 WRX
  • 2005-2009 LGT
  • 2004-2013 FXT *Kits for the 09-13 FXT are not direct bolt on and currently require custom mounting*

When we tune these kits on an Accessport we give you 2 tunes with the only difference being the starting strategies. Both tunes are full flex fuel, we just adjust the starting tables so your car will start on E85 at even the coldest Minnesota temps. This is the only downfall we have found with these kits and it’s a pretty small one if you ask me. These kits don’t have 2 starting strategies in one tune like the Cobb software allowed. The only time you ever need to flash the other map is if you switch fuels. That only takes about 5 min at the gas station to do when you fill up on the new fuel. Most of these kits are compatible to be used when tuning opensource, except the 2015-2021 WRX, if you plan on running E85 year-round too. This opens the door for a lot of customers who want flex fuel but don’t have an Accessport.

Email us at tuning@jmautomn.com, call us at 763-316-5882, or message us on Facebook today with any questions you have.