12-7-2023 Update-
Cobb has rereleased flex fuel kits for the 2008-2021 STI and the 2015-2021 WRX is rumored to be released next. The Cobb flex fuel kits and tuning solution are true flex fuel and much better making this option now obsolete.
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. They had these kits 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. We have found 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. We can use that signal 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.
What’s the catch?
When we tune with these kits on an Accessport we give you 2 tunes. 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 ethanol 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. An example is if you have pump gas currently in the fuel tank and decide to pump E60. You would want to flash the E60 map so the starting / warmup tables are correct for ethanol. If you are always running ethanol or pump gas there is no need to change maps. Flashing a map only takes about 5 min at the gas station 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.
What vehicles do these kits work on?
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*
Click here to check out the Delicious Flex kits along with many other performance parts.
Email us at tuning@jmautomn.com, call us at 763-316-5882, or message us on Facebook today with any questions you have.