86, GR86 & BRZ Tuning Done Right — The Twins, Finished
The chassis is world-class and the engine wants help. I build the twins into the car they should have shipped as. That means giving one of the best-handling platforms ever built the power it's begging for — but doing it in the right order, because the FA boxer has real habits that punish a rushed build.
The 86, GR86, FR-S and BRZ are the best-balanced, most tossable rear-drive cars money buys, and everyone who owns one eventually wants more grunt to match the grip. Bolt-ons and a tune wake up throttle response but add little peak power — this is a forced-induction platform once you want real numbers. A supercharger keeps the linear, revvy character; a turbo reaches higher. But the FA24's oil-starvation behavior under hard cornering and the FA20's reliability quirks have to be respected first, or you've added power to a motor that's about to protest.
My position is simple: I build the twins the way the factory should have, but I fix the engine's known weak points before I add the power, not after. Whether it's a mild supercharger on a street car or a built, forced-induction track weapon, I address the oiling, the carbon and the recall history first — because on these cars, the difference between the car it should have been and an expensive lesson is a shop that respected the boxer's habits.
86, GR86 & BRZ Engines: FA20D, FA24 & Built Blocks
Which generation you have decides the engine, the failure profile and the build. The two boxers share a philosophy and a family name — but not their weak points.
FA20D (first-gen)
The naturally aspirated 2.0-liter boxer in the first-gen 86, FR-S and BRZ, using Toyota's D-4S dual port-and-direct injection — the port side helpfully washes carbon off the intake valves. Not to be confused with the WRX's turbo FA20DIT. Its own story includes the 2013 valve-spring recall, which is the first thing to verify on any early car.
⤢ Click to enlargeFA24 (second-gen)
The 2.4-liter boxer in the current GR86 and BRZ — more torque and no valve-spring defect, but the platform carrying the well-documented oil-starvation behavior under hard cornering, especially on right-hand turns. A great engine that rewards an owner who addresses its oiling before tracking it.
⤢ Click to enlargeBuilt & boosted blocks
When you want real power, a closed-deck built short block with forged internals is the foundation — a higher-compression spec for a supercharger or low-boost, or a lower-compression spec built for 400-plus wheel horsepower of turbo. This is where the twins finally become the car the chassis always deserved.
⤢ Click to enlargeWhichever boxer you have, real power comes from the adder and the calibration — a supercharger for linear, revvy power, plus a proper custom ECU tune that matches the exact kit and handles the boxer's fueling. I build the twin you have into the car it should have been.
Signs Your FA Boxer Needs Attention — and What to Watch
The FA has a set of named, specific tells worth knowing. On the FA24, an oil-pressure warning light with a ticking or knocking under load is the RTV-sealant strainer-clog symptom — often a one-time issue once cleaned, not a recurring one. More telling is an oil-pressure drop specifically on hard right-hand turns: because of the oil-pickup geometry, right turns are worse than left for the FA24's oil-starvation behavior, which is genuinely non-obvious and worth naming plainly. And a quart of oil consumed every few hundred miles under hard driving is a real FA sensitivity — a 'check this before you panic' symptom, not necessarily a failure.
Other tells are smaller. Early second-gen cars can have a squeaky clutch pedal or notchy shifting from insufficient factory grease on the throwout bearing and fork, and early first-gen FA20 cars sometimes idle roughly or stall at low speed from an ECU mapping issue fixed by a dealer update. The single highest-value reliability mod across the platform is an air-oil separator, which intercepts the oil vapor blow-by that otherwise lowers effective octane and raises detonation risk. The clearest signal a twin needs a real tune is a car that's had a supercharger or turbo bolted on without the oiling addressed — because on this platform, power without the oiling handled is a countdown, and hard cornering is exactly what a drift or track day delivers.
How to Build Your 86, GR86 or BRZ — A Los Angeles Owner's Guide
Building a twin right is four decisions. Get them right and the chassis finally has the engine it deserves; get them wrong and you've starved a boxer on a right-hander.
- Decision 1 of 4
Fix the oiling and reliability first
On any FA build, the oiling comes before the power — an air-oil separator on every car, and a real oil strategy on a tracked FA24, because its starvation behavior under hard cornering is an eventuality, not a maybe. On an early FA20 I verify the valve-spring recall was done. The boring parts first, because they're what keep the fun parts alive.
- Decision 2 of 4
Supercharger or turbo
A supercharger keeps the linear, revvy character the twins are loved for and is the simplest to live with; a turbo reaches higher power. Naturally aspirated bolt-ons alone add little peak power, so if you want real numbers, forced induction is the honest path. I match the adder to how you drive — street sweetness or track punch.
- Decision 3 of 4
Know when the block needs building
The stock boxer takes a sensible amount of boost, but real power — 400 wheel horsepower and up — wants a closed-deck built short block with forged internals, in the compression spec that matches your adder. I set the target against that line, so we build a strong car on the stock block or a proper foundation to go past it, never an over-boosted stock motor.
- Decision 4 of 4
Tune it, and mind the oil cooler
Every forced-induction twin gets a proper dyno tune to the exact kit and fuel. And a real, non-obvious detail: an oil cooler can rob 5 to 10 psi from the system, which matters enormously on a platform already fighting oil pressure — so I plumb it as part of the oiling strategy, not a bolt-on afterthought that makes the problem worse.
What a GR86 or BRZ Build Costs in Los Angeles
Here's the honest range by build level, based on what the LA market charges in 2026. Naturally aspirated bolt-ons do little for peak power, so the money that matters goes to the adder and, for big power, the block. I publish these because it's easy to spend on the wrong things first.
Bolt-ons + tune
Intake, exhaust, an air-oil separator and a tune — sharper response and a clean, protected baseline.
- Custom tune
- AOS included
- Better throttle
Supercharger / turbo kit
A supercharger or turbo kit, oiling protection and a full tune — the real answer to the engine's shortfall.
- Kit + install + tune
- Oiling protected
- Linear or high power
Track oiling package
The oiling strategy for a tracked FA24 — overfill, cooler done right, and the supporting fixes.
- Oil-starvation defense
- Cooler plumbed right
- Track-ready
Built FI motor
A closed-deck forged short block and big turbo or blower for serious, repeatable 400-plus wheel horsepower.
- Closed-deck forged
- Big turbo or blower
- Built to live
What moves your number: your power target, whether you're supercharged or turbo, and how hard you track the car — which decides how much oiling defense it needs. Tell me the goal and how you drive it, and I'll build a twin that makes it — and keeps making it.
FA Boxer Technical Guide — Oiling, Boost & Power Paths
You don't need to be a Subaru engineer to build an FA well, but the oiling story is the one that saves the motor.
The FA24 oil-starvation mechanism. Per Subaru's own documentation, the FA24 oil pump flows nearly 49 quarts a minute at 6,000 rpm — enough to theoretically empty a four-quart lower pan in about five seconds if return flow lags. Under sustained cornering, oil pools in the cylinder heads and starves the pickup, and it's worse on right-hand turns. This is the platform's defining engineering fact, and it's why a serious build is an oiling conversation before it's a power one.
The honest fix debate. No single cheap part solves it. A baffled pan slows sloshing but doesn't address head-pooling, and some data questions its benefit. A modest half-to-one-quart overfill is the most consistently recommended low-cost mitigation. An AccuSump works but is expensive and complex; a dry sump is the real fix but requires custom fabrication since no off-the-shelf FA24 kit exists. And an oil cooler — while good for heat — can cost 5 to 10 psi of oil pressure, which matters on a platform already fighting it. I build the right combination for how hard you run the car.
Power paths and the boxers. Bolt-ons sharpen response but add little peak power — this is a forced-induction platform for real numbers. A supercharger keeps the linear character; a turbo reaches higher. Serious power wants a closed-deck forged block in the right compression spec, and an air-oil separator on any build to stop oil-fouled intake air from raising knock. The FA20's D-4S port injection helps with intake carbon, but a walnut blast every 40,000 to 60,000 miles is still smart maintenance.
86, GR86 & BRZ by Generation — FA20D vs FA24
Fitment on a twin is a generation-and-engine question — which FA you have decides the failure profile, the checks and the build.
First-gen and the recall. The 2013-to-2020 86, FR-S and BRZ run the FA20D, and they carry the 2013 valve-spring risk — a fractured spring can drop a valve, so verifying the recall is done comes before any performance work. This is the Subaru-built boxer at its lightest, and the twins share their boxer DNA with the WRX and STI — though the 86's naturally aspirated FA20D is a different engine from the WRX's turbo FA20DIT. As a Subaru-blooded chassis, an 86 makes a surprisingly game rally and gravel car.
Second-gen and its habits. The 2022-plus GR86 and BRZ run the FA24 — more torque, no spring defect, but the oil-starvation profile to respect on track. Whichever generation, this is a chassis that lives for corners, which is why it's a favorite lightweight tool alongside the other great cheap-thrills rear-driver, the Miata and MX-5. Build the oiling right and add the power the chassis has always deserved, and the twins become genuinely special.
5 86 & BRZ Mistakes LA Shops Make — And How I Do It Differently
I've fixed a lot of twins that a shop boosted without respecting the boxer. The five mistakes I see most:
1. Selling a baffle as the oil-starvation fix
A baffled pan is a partial mitigation at best, and some data questions its benefit — it doesn't stop oil pooling in the heads under G-load. I build a real oiling strategy for how hard you track the car, and I'm honest that no single cheap part makes the problem disappear.
2. Skipping the first-gen recall check
Building power on an FA20 with unaddressed valve springs is a genuine liability — a broken spring drops a valve. I verify the 2013 recall was completed before any performance work on an early car, every time.
3. Aggressively overfilling oil 'to be safe'
Too much overfill causes aeration and PCV problems — the safe range is half a quart to a quart, not an arbitrary amount. I dial the overfill precisely, because 'more' past a point makes the oiling worse, not better.
4. Bolting on an oil cooler without the pressure math
An oil cooler can rob 5 to 10 psi, which is a big deal on a platform already fighting oil pressure. I plumb it as part of the oiling strategy, weighing the pressure cost, instead of adding one and accidentally worsening the starvation.
5. Adding boost before the oiling
Power on top of an unaddressed FA24 oiling problem is a countdown, especially on a tracked car. I fix the oiling and the air-oil separator first, then add the power — the right order the platform demands.
Tuning an 86 or BRZ in Los Angeles, CA — Canyons, Heat & Grip
LA is where the twins live their best life — and where their habits show up. The canyon roads and autocross lots that suit the chassis so perfectly are exactly the sustained cornering the FA24's oiling hates, and the heat only sharpens the point.
The grip is the point — and the risk. Angeles Crest, GMR and Mulholland are exactly the long, hard corners the twins were built for, and exactly where an unaddressed FA24 pulls oil away from the pickup. So in LA the oiling defense isn't optional on a car that sees canyons or lapping days — it's the whole foundation. The chassis rewards good suspension as much as power, which is why a proper coilover and corner-balance setup is often the best first money on a twin, before any boost. And 91-octane heat means a tune calibrated for the hot day, not the cool dyno cell.
The best-value grip in Southern California. The 86 and BRZ are among the best autocross cars for the money there is — light, balanced and endlessly adjustable — which is exactly why so many LA owners eventually want the engine to match the chassis. Do it in the right order: oiling and reliability first, then the supercharger or turbo the car has always deserved, tuned for LA's heat. That's how the twins become the car they should have shipped as — and stay that car under real, sustained load.
How I Tune and Build Your 86, GR86 or BRZ
Every twin build follows the same disciplined arc, whether it's a bolt-on tune or a built, boosted track car. No mystery, no shortcuts.
- Step 1 / 5
Assess the car and the goal
We confirm which FA you have, its failure profile, and how hard you drive the car — street, canyon or track — plus the honest power goal. You get a plan that puts the oiling and reliability before the power, and verifies the recall on an early car, before any boost target is set.
- Step 2 / 5
Protect the oiling first
An air-oil separator on every build, and a real oiling strategy on a tracked FA24 — the right overfill, a cooler plumbed with the pressure cost in mind, and the supporting fixes. The protection goes in before the power, because on this platform it's the whole ballgame.
- Step 3 / 5
Add the adder, build if needed
The supercharger or turbo goes on, and if the target is past what the stock block should hold, a closed-deck forged short block in the right compression spec goes under it. See how a boxer build comes together in my build process.
- Step 4 / 5
Dyno-tune to the kit and the heat
On the loaded dyno I calibrate to the exact adder and fuel, watching knock and air-fuel every pull and accounting for LA heat, and verify it hot with back-to-back runs. The tune matches your car, not an average of someone else's.
- Step 5 / 5
Deliver, log and support
You leave with the logs, a plain-English walkthrough of what the car wants, and a twin that finally has the power its chassis deserves — protected, repeatable, and built to live on a canyon or a track day, not just to screenshot.
86, GR86 & BRZ Tuning Questions, Answered
Is the GR86 and BRZ oil-starvation problem really that bad?
Does a baffled oil pan fix the FA24's oiling issue?
What's the safest fix for FA24 oil starvation on a track car?
Is the FA20 in my BRZ the same engine as the WRX's turbo engine?
What was the 2013 valve-spring recall about, and does it affect my car?
Why does an oil cooler matter so much on this platform?
86, GR86 & BRZ Tuning Across Greater Los Angeles, CA
My shop and dyno are in West Covina, in the San Gabriel Valley. Twin owners bring me their 86s, FR-Ss, GR86s and BRZs from the near ring, the mid ring and the South Bay because they want the engine the chassis deserves — with the oiling protected first, not after a right-hander. Tap your city:
Brands We Trust
I build twins on the brands that have earned it giving the FA boxer real, reliable power — forced induction, internals, oiling and tuning that hold up on real 86 and BRZ builds — not because there's a poster on the wall. When your twin goes on the bench, these are what I reach for.
// The twins, finished. Built for LA.
Let's build your 86, GR86 or BRZ right
Tell me your engine, your power goal and how hard you drive it. I'll protect the oiling and reliability first, then add the supercharger or turbo the chassis has always deserved — tuned for LA heat and built to live.