Independent European-focused specialist in Ferndale, Washington. From board-level ECU diagnostics to custom big-turbo fabrication — the work most shops outsource.
Dark Horse Performance is the independent workshop of Kory Scroggins a Ferndale-based European specialist with over a decade of hands-on experience across Volkswagen, BMW, Audi Etc. platforms.
Kory works at a depth most shops outsource. Every job is treated like a personal build researched, documented, and finished only when it's right.
Backed by trusted parts partners and a network of fellow craftsmen across the Pacific Northwest, Dark Horse is where European cars come to be understood not just repaired.
Pulled directly from the work documented on the bench these are the disciplines Dark Horse executes day in, day out.
GTX-series turbo upgrades, plenum and charge-pipe fabrication, stage 2+ tuning, and the supporting fuel/boost infrastructure to make it all live.
Board-level coil driver MOSFET testing, limp-mode and fault-code resolution, ICM and sensor work. The diagnostics most shops won't even open the lid for.
CP4 to CP3 conversions on TDI platforms, rail and injector diagnostics, contamination cleanup, and complete fuel-system rebuilds when failure has spread.
One-off plenums, charge piping, thermal heat insulation wrap, hardline vacuum routing, and weld repair on cast aluminum. Built once, built right.
Full VR6 and inline rebuilds, balanced rotating assemblies, head work, and complex platform swaps (automatic-to-manual harness work included).
Dark Horse offers ECU tuning built around your setup not a generic map. Using MHD, VCDS, and platform-specific tools across BMW, VW, and Audi, every tune is dialed to your goals, your fuel, and how the car actually behaves. No guessing. Just results you can feel.
Real builds, real diagnostics, in Kory's own words.
Quick test on the coil driver MOSFETs inside the MSD80 DME notorious failure points on the pre-facelift N54 when coil demand is pushed. This 335i is running 19T turbos at 18psi, full bolt-ons with @precisionraceworks coils and @armmotorsports downpipes. After MHD stage 2+, a medium-load pull revealed the known weakness.
CJAA TDI towed in after shutting off on I-5 all components testing electronically fine but no rail pressure. Pulled the fuel quantity sensor from the CP4 high-pressure pump and found a glitter party in all the wrong places. Pump cam follower spun 90° as they all eventually do. Converted to a reliable Fisher R70 CP3 kit from @cascadegermanparts, cleaned the entire fuel system, and replaced the filter housing. Customer back on the road — no more ticking time bomb.
GTX2867R at 21psi was too much for the 2" charge pipe, so 2.5" thru-and-thru should flow a whole lot easier. Now to get Gonzo at @gts.performance to help finalize the tune and get the VVT running so Elsa can get out there and eat.
After months of research and tooling, Dark Horse Performance is now offering custom 304 stainless thermal heat insulation for anyone looking to lower bay temps. These headers are for a special build — @faction_automotive's LS-swapped BMW. Not only will they keep temps down, but who doesn't love how beautiful these headers are going to look in the bay. Got Rev limiter–bouncing exhaust components? Let's protect that investment.
Worked on this absolutely amazing E82 1M Coupe for @1mprsv1. Full interior Alcantara upholstery with Recaro RC powered seats, carbon seat backs, carbon accents throughout, BMW performance steering wheel with factory wiring and matching Alcantara airbag cover, RTD short shifter, carbon diffuser, and Bayoptiks headlights. Long nights — worth every second.
Premium parts, performance hardware, and dealer-alternative expertise. Every job at Dark Horse is supported by a parts partner that takes European platforms as seriously as we do.
JH Motorsports is a full-service performance and maintenance facility specializing in Audi, Volkswagen, and Porsche. As a premier APR Tuning dealer and authorized JHM Tuning supplier, they stock thousands of OEM and German-made replacement parts — with multiple deliveries daily for everything they don't.
When your build needs the right parts the first time, this is the network behind the bench.
Visit jhmotorsports.comReal reviews from European owners across Whatcom County.
"Brought my BMW 540i in for overheating issues and some other things I couldn't figure out on my own. Kory got into it fast and came back with a thorough breakdown of everything going on — not just the obvious stuff but the root causes behind it. Pricing was very fair for the level of work and knowledge he brought to the table. This is the kind of shop where you can tell the guy actually knows BMWs, not just how to plug in a scanner. Will be back."
"My 2012 Audi A4 2.0T Avant started throwing a lean code and had a rough idle at startup that would smooth out after a few minutes. Took it to two shops before Kory — both just kept throwing parts at it. Kory pressure tested the intake, found a cracked accordion hose behind the air filter box and a weeping valve cover gasket that was letting oil fumes mess with the MAF readings. Fixed both, cleared the codes, and the car has been dead smooth ever since. Didn't charge me for half the diagnostic time he put in. That kind of honesty is rare."
"CP4 failed on my TDI on I-5. Kory walked me through the conversion to a CP3, sourced the parts, and got me back on the road. Knows these cars cold. Won't take it anywhere else."
Solo shop, focused work. Drop a note with your vehicle and the symptoms — Kory will get back to you to schedule.