Saturday, July 23, 2022

Corn-fed Catalyst - FlexFuel for the STI

 

2016 Subaru WRX STI Series.HyperBlue

It had been part of my plan for upgrading this car for awhile, but sitting around waiting for the Pandemic to pass got me itching for some speed.  The next obvious step power-wise for my WRX STI was to run E85 fuel.  Along with that goal came several other changes to optimize things for greater power gains and increase reliability as I continue to push both this car's capabilities and my own.  This took several months of research and planning to get right, but I'm glad I did my homework as the results have been that much more satisfying.

For the E85 upgrade, I chose to go with the COBB FlexFuel kit.  With travel plans taking me places away from E85 availability, it just made sense to fully utilize a FlexFuel type setup so whether I could only find 91 Octane or full-fledged corn juice, I wanted to be able to continue whatever routes lay ahead.  With that came ID1050X fuel injectors and a DeatschWerks DW300C fuel pump.  While we were installing the kit on the engine, we also removed the TGVs and EGR.  We used Torque Solutions block off plates to finish things up for that delete.  

This was all done long before news of the emissions requirements COBB would later implement, so I slightly regret going that direction.  If I ever need to change or tweak anything tune-related, I will need to get all of the emissions-related items back on the car.  As it stands, this STI has no catalytic converters, no TGVs, and no EGR.  I would be able to find a downpipe with a catalytic converter and re-install the EGR, but because the TGVs were removed directly from my manifold, I would need to source another manifold with the TGVs intact.  Essentially, this current setup is the best it can.  Any further improvements would also need me to reinstall the emissions-related items.

I already had installed an Air Oil Separator, but it also seemed wise to address cooling issues inherit with the EJ257.  The TGV delete and most of the install was performed at Russ' Garage, with whom I have had much success with over the last 10 years.  They did a top-notch job installing things and worked with my tuner to ensure proper methods were used when setting up the FlexFuel system.  We did a Cylinder 4 Coolant mod to improve circulation within the stock block.  We also ended up re-routing some of the AOS coolant lines to improve the layout and clean things up under the hood.  With all that installed, buttoned up, and a base tune installed, I carefully drove the car to Boosted Performance Tuning for a session with Graham.

This was my third time meeting with Graham for tuning and marked 4 years of working with him in general.  It's always a pleasure to work with someone so knowledgeable that is also easily approachable.  He has always been receptive and respectful when I've had questions no matter what.  At the time of tuning, Graham noted that I was still using the stock clutch in my STI and recommended we dial the torque back a bit to ensure reliability and keep me from tearing it apart.  I ran on that tune for almost two years before revising it just before all of the emissions restrictions imposed by COBB took place.  He was able to make quick revisions to the tune and I'm grateful that the new clutch that will go in will be able to make use of the full potential of tuning we had originally done in 2020.


What's Next?

I need to get caught up on build information on this blog and more articles and reviews will be written for the changes I've made.  New parts, new partnerships, and new goals to compete with the car again are all in place.  In fact, this very article was something I started writing in June of 2021 but had since drifted away from writing.  Life keeps me busy but it is always enjoyable to write, so I'm hoping to record all of that here once again.  If you'd like to see more, please leave a comment.  I tend to find more value in writing these when others are showing interest or have questions.