Subaru WRX / STI tune. Nashville.
The WRX (FA20 turbo) and STI (EJ257 turbo) are two of the most well-documented tuning platforms in the JDM world. Stage 1 alone picks up 50+ wheel hp on stock turbo. Stage 2 with downpipe + intake + intercooler pushes past 380 on the right supporting mods.
Every Carma tune includes.
Real prices, no dyno-number runaround. Here's what comes with every flash — at no extra charge.
What we do for the wrx / sti.
Stage 1 unlocks the FA20 or EJ257 safe envelope on 93 octane. We've mapped Subarus for over a decade — the playbook is mature. Stage 2 with bolt-ons + ethanol blend is well-trodden territory.
Straight talk, because Subaru owners have earned it: the EJ257's ringland reputation is real, and the cure is disciplined calibration — conservative knock margins, honest fueling, and a health check before the flash, not after the tow. That's how we tune every STI. The newer FA-series cars (2015+ WRX FA20DIT, 2022+ FA24) are stouter platforms with their own maps, and flex-fuel is the ceiling-raiser across all of them.
- Stock file pulled and archived (free stock-revert anytime)
- Custom-mapped per platform (FA20 vs EJ257)
- Safe map flashed and road-tested in-house
- E85 / flex-fuel mapping common on this platform
- Lifetime support on revisions
Pricing for the subaru wrx / sti.
Mods we pair with this tune.
The Subaru path, tuned for longevity first:
- Turbo-back exhaust / J-pipe — the platform’s classic unlock — FA cars especially respond to the J-pipe.
- Front-mount or upgraded TMIC — heat is the boxer’s enemy; cooling is the consistency mod.
- Flex-fuel kit + fueling — injectors + pump + sensor — the E85 path that transforms the car.
- AOS / catch can — boxer crankcase management; cheap insurance under boost.
- Pre-tune health check — compression + leak-down before the map. Non-negotiable on EJ cars.
No dyno-number games, no hard sell. Drive it, and if the tune isn't for you, we revert to stock at no charge. That's how confident we are in the map.
Common questions.
WRX vs STI — different tune?
Yes — completely different engines (FA20 in the WRX, EJ257 in the STI through 2021). We tune each as its own platform.
Stock turbo limit?
WRX stock turbo: ~330 wheel hp. STI stock VF48: ~380 wheel hp. Past that, upgraded turbo is the next step.
Is the transmission rated?
STI 6-speed is robust. WRX CVT is the limiting factor on power — TCM tune helps but it's not a built-engine candidate.
How long does the appointment take?
Stage 1: 2 hours. Stage 2 with mods to install: half-day to full day.
Is the EJ257 safe to tune, honestly?
Yes — with discipline. Conservative knock margins, correct fueling, and a pre-tune health check keep the EJ alive; the ringland failures you’ve read about are almost always aggressive maps or hidden pre-existing wear. We tune for the long game.
Do you tune the 2022+ WRX (FA24)?
Yes — the FA24 is a stouter, direct-injected platform with its own calibration path. Solid Stage 1 gains, and the flex-fuel story is just as good.
What does the flex-fuel setup involve?
Ethanol sensor, injectors, pump, and a map that blends live from pump 93 to E85. It’s the single biggest transformation available on any Subaru and we spec the whole path before you spend.
Book your Subaru WRX / STI tune.
Drop it off in the morning, drive it home tuned by end of day. 1035 3rd Ave S, Nashville, TN 37210 · Mon–Fri 8 to 5.