Serving Diamond Bar import & tuner owners · West Covina, CA

Import & Tuner Performance Shop — Diamond Bar

Black Sheep Tuner Garage is about fifteen minutes southeast toward the 57/60 from Diamond Bar — a JDM and European performance shop building honest power for Diamond Bar owners who want the work done right the first time.

// Diamond Bar to dialed in. Close enough for the drive, serious enough to be worth it.

15 min SE from Diamond Bar JDM & Euro owner-led 4.9★ · 312 reviews
Worth the short drive

Why Diamond Bar Drivers Make the Drive

Diamond Bar has no shortage of shops that will flash a tune and hand you a slip. What it doesn't have on every corner is a builder who tells you the truth about your car before taking your money.

That's why Diamond Bar owners point their cars about fifteen minutes southeast toward the 57/60 to my shop in West Covina. It's a short hop across the hilly, rolling east-valley suburb, and the reason people make it is simple: they want a build spec'd to their real goal and their real fuel, not a parts-cannon aimed at a number they'll never use. I'd rather send you home with the honest version of your build than the expensive one.

Popular builds & real LA pricing

What Diamond Bar Owners Build Most

These are the four builds I see most from Diamond Bar — with real Los Angeles price bands, not “call for a quote.” Nearly every one starts with the tune; the rest is where you take it.

Where every build starts

Dyno & ECU Tuning

$400–1,200

The foundation of every build — a custom ECU calibration proven on the loaded dyno, safe for LA heat and 91 octane.

  • Flash, e-tune or full custom
  • Verified on the dyno
  • Logs you keep
⤢ Click to enlarge

Turbo & Forced Induction

$3,500–8,000+

Bolt-on to big-single turbo builds, sized to your real target and backed by the tune to hold it.

  • Turbo, fueling & cooling
  • Fabrication + install
  • Tuned as one system
⤢ Click to enlarge

Coilovers & Suspension

$1,900–4,000

Coilovers installed, corner-balanced and aligned — the difference between just lower and actually handling.

  • Install + ride height
  • Corner balance + align
  • Set up for your roads
⤢ Click to enlarge

Exhaust & Downpipes

$700–2,500

Catback, downpipe or turbo-back that flows — with a straight answer on what's smog-legal here.

  • Catback to turbo-back
  • High-flow, CARB-honest
  • Paired with the tune
⤢ Click to enlarge

Real starting bands, not fixed quotes — the number moves with your platform, parts and power target. Bring me the car and the goal and you'll leave with a straight figure, in writing, before anything comes apart.

START YOUR BUILD
Built for how you actually drive

What Diamond Bar Roads Ask of a Tuned Car

roads · Grand Ave built for Canyon Evo · WRX/STI tuned for 91 · E85

A car built for Diamond Bar has to live in the real world around it — Grand Avenue over the hills and Diamond Bar Boulevard, plus the LA heat and stop-and-go that every SGV build has to survive. That shapes how I spec a car: a tune that stays safe hot, cooling that holds up, and suspension set up for the roads you actually drive. Around here that often means the Mitsubishi Evo or Subaru WRX and STI — but whatever you drive gets built to the platform, not a template.

Some Diamond Bar owners take it further. Grand Avenue over the hills and the foothill roads reward a car that actually handles. If that's the direction you're headed, a canyon build is the kind of build I set up for owners near Diamond Bar.

Trusted by owners near Diamond Bar

What Diamond Bar-Area Import Owners Say

A 4.9-star reputation across 312 reviews, earned one honest build at a time — including owners right around Diamond Bar.

★★★★★

Came in wanting the biggest turbo I could afford. He walked me through why the right-sized one would be faster and more reliable for how I actually drive. Car rips and it's still my daily.

Priya N. · Diamond Bar · Civic
★★★★★

Rodrigo talked me out of a built motor I didn't need and put the money into a proper tune instead. My WRX makes more usable power than my old shop's “Stage 3,” and it hasn't skipped a beat since. Honest is rare in this scene.

Marcus D. · West Covina · WRX
★★★★★

The dyno tune on my Supra was the whole difference. Same parts, way more power, and he walked me through the logs. He tunes for the car living a long time, not just a big peak number.

Sam P. · Long Beach · Supra
Easy to reach

Getting to the Shop From Diamond Bar

The shop  ·  555 S Glendora Ave, West Covina, CA 91790

From Diamond Bar  ·  about fifteen minutes southeast toward the 57/60 on the 57 and 60 (and the notorious 57/60 confluence)

Between  ·  Rowland Heights, Walnut, Pomona and Brea

Hours  ·  Mon–Fri 9am–6pm · Saturdays by appointment

Call ahead  ·  (626) 555-0183 — so I can give your car real attention when you arrive instead of catching me mid-build.

Where I serve

Proudly Serving Diamond Bar & Greater Los Angeles

My shop is in West Covina, in the San Gabriel Valley, and owners bring me builds from Diamond Bar and across the metro. Tap your city:

Diamond Bar owners ask

Questions Diamond Bar Drivers Ask Us

Is Black Sheep worth the drive from Diamond Bar?
For an honest build, yes. The shop is about fifteen minutes southeast toward the 57/60 from Diamond Bar on the 57 and 60 (and the notorious 57/60 confluence) — a short run, and owners come from across greater Los Angeles for the same reason: a builder who tells you the truth about your car and backs the work on the dyno. A tune done right once beats a cheap one you pay to fix twice.
Do you tune Diamond Bar daily drivers, not just race cars?
Most of what I build are street cars — dailies and weekend cars for Diamond Bar owners who want more power that still behaves in traffic and survives Grand Avenue over the hills and Diamond Bar Boulevard and the heat. A good daily build is spec'd to stay reliable, not just to hit a dyno number, and that's most of the work that comes through the door.
Do you work on both JDM and European cars?
Both. Whether it's a Subaru, Honda, Toyota or Nissan or the BMW, VW-Audi, Mercedes and Porsche side, I build them all — and knowing both is how I keep from forcing a Diamond Bar owner's car into a build that fits my comfort zone instead of their goal.

// Diamond Bar to dialed in. Let's build it right.

From Diamond Bar to Dialed In

Make the short drive from Diamond Bar and let's talk about your car — the platform, the goal and the fuel. I'll tell you honestly what it needs, then build it to a number you can stand behind.