My 2018 Subaru WRX Build: Engine Mods, E85 Tune, and a Whole Lotta Fun

Motor God’s Marketing Strategist GI Griffin talks about his Subaru WRX build and mods.

There’s something magical about taking a car and tailoring it to match your personality. For me, cars are more than a mode of transportation. They’re an extension of who we are—a canvas for innovation, style, and pure, unfiltered fun. When I first laid my eyes on the Subaru WRX in 2018, I knew I’d found my perfect canvas.

What started as a stock WRX has since transformed into a custom beast with refined power and a whole lot of personality. From high-performance mods to a custom e85 tune, this is the story of my 2018 Subaru WRX build.

Why I Chose the Subaru WRX Over the STI

After months of research (and endless debate), I nearly pulled the trigger on the Subaru STI. I mean, what’s not to love? Solid base power with room to grow, rally heritage, and that signature Subaru rumble. But there was something about the WRX that called to me.

For one, I wanted a higher compression engine for improved off-boost power. The turbocharged FA20 engine in the WRX offered just that at 10.6:1 compression ratio. Plus, it gave me the freedom to explore modifications without feeling like I was starting with a finished product. Long story short, I saw potential—and I’m glad I trusted my instincts.

Oh, and my test drive? Legendary. My car salesman—clearly as Subaru-obsessed as I am—took me out to literally spin donuts right outside the dealership. Dude was a mad man, you don’t forget a test drive like that!

Putting the WRX to the Test

The first thing I did after bringing my WRX home? Took it off-road to see how it handled the dirt. (Spoiler alert: like a CHAMP.) I even launched it three feet into the air because I got too excited—and it didn’t break a sweat. It was then I knew this car wasn’t just built for daily commutes; it was ready for adventure.

Now that I was sold, it was time to transform this stock WRX into something uniquely mine. That meant MODS. Lots of mods.

Engine Modifications That Turned My WRX into a Beast

If you’re a car enthusiast, you know that modifying a vehicle is as much about strategy as it is about passion. My goal was simple—to create a daily driver that was fun, reliable, and environmentally conscious (yes, clean gas matters!). Here's the lowdown on the mods that took my WRX to the next level:

1. GrimmSpeed Intercooler

The GrimmSpeed Top Mount Intercooler was hands-down my favorite modification. Turbocharged engines love cold air, and reducing heat soak made a tangible difference. With this upgrade, the air charge stayed cool, delivering reliable and consistent power during spirited driving and going WOT.

2. Cobb Cold Air Intake System

This addition brought more than just improved airflow—it gave the car attitude. The added turbo spool sound and blow-off noise were music to my ears. Performance + ear candy? Worth every penny.

3. E85-Ready Fuel System

Switching to e85 fuel required upgrading the entire fuel system (pump, filter, and lines). Why? Because e85 is less lubricating than regular gas and demands specialized components. Bonus tip: I run a mix of e85 with a little 91-octane for added lubrication and fuel pump reliability.

4. High-Flow Fuel Injectors

With extra boost comes the need for extra fuel. High-flow injectors ensured the engine got the fuel it craved to handle the added performance. (Not going to lie, I did blow my injectors in the first month and had to spend $2000 to have them replaced. This is why you don’t go WOT in 6th gear lol.)

5. TGV Delete

More airflow? Yes, please. The TGV delete contributed to both increased turbo boost pressure and an extra bump in power.

6. EGR Delete

The EGR delete improved throttle response, added horsepower, and increased overall efficiency. Fewer carbon deposits, better performance. A win-win.

7. E85/91 Octane Tune

The cherry on top of this build was a custom tune by Travis Barnes at Snail Performance in Northern California. Travis dialed in a 91-octane map and an e85 map, all loaded onto a Cobb Tuning Accessport. This allowed me to monitor engine performance, ethanol mixture, and switch fuel maps at the touch of a button.

Performance Results

After months of hard work and plenty of test drives, I was happy modest numbers it put down:

  • 327 whp

  • 330 wtq

And this was while keeping reliability at the forefront! Remember, this is my daily driver, not a track-exclusive project. The best part? The ride was consistent—no hiccups, no surprises. Travis absolutely nailed the tune with a very linear powerband. My goal wasn’t extreme power, my goal was balance—enough power to have fun while maintaining the reliability I needed for everyday life. Full boost, clear skies, and a slightly blurry view out the windshield. What more could I ask for?

Why E85? A Quick Note on Clean Fuel

One of my priorities with this build was finding a way to enjoy peak performance and still be environmentally conscious. Enter e85—a clean-burning alternative to regular gasoline. While not the easiest fuel to come by in every area, its reduced carbon emissions and high octane rating made it a no-brainer for this project. The result? An engine that’s powerful, responsive, and just a little kinder to the environment.

Final Thoughts: Building Your Dream Subaru WRX

Every engine mod I chose was geared towards creating a Subaru WRX that perfectly fit my needs—a car that’s fun, reliable, and uniquely mine. Whether you're just getting started or already deep in the modification world, remember this—building your dream car is a personal journey. It’s about finding what excites you, learning by trial and error, and celebrating the ride (literally and figuratively).

Thinking of starting your own Subaru WRX build? My advice:

  • Do your research. Make sure every mod aligns with your goals.

  • Find a great tuner—someone who understands your vision.

  • Don’t rush the process. The best builds take time.

If you’re as obsessed with cars as we are at Motor Gods, why not check out our collection of car-inspired gear? From bold apparel to accessories inspired by the open road, we’ve got something to fuel your passion for driving. Visit Motor Gods to shop, learn, and connect with a community of car enthusiasts like you.

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My 2018 Subaru WRX Build & Custom e85 Tune 

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Discover GI Griffin’s Subaru WRX build, showcasing engine modifications, a custom e85 tune, and how it delivers fun, power, and reliability!

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