Performance Dyno tuning & wiring solutions

Located in Portland, Oregon

Website undergoing changes - Stay tuned

At JMRacing, we specialize in wiring, tuning, and calibration for motorsport and performance applications. Whether you’re building a dedicated track car or refining your street setup, we help you unlock the full potential of your engine.

You get a complete solution — not just a tune that makes power on paper. From cold start to redline, we focus on real-world performance, reliability, and driveability. With our Mainline hub dyno, you get accurate, consistent results without tire slip or guesswork — so you know exactly what your car is capable of.

A black race car drifting around a curved race track, producing white smoke from its tires with a wooded background.
View of a race car engine bay with visible turbocharger, intercooler pipes, and various performance modifications.

Nissan S14 | 2JZ-GTE with JMRacing Engine Loom & PDM Chassis Harness

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Our Services

  • Dyno Tuning - Mainline Prohub 2wd 2000hp

    Take advantage of our superior Mainline hub dyno for precise, repeatable measurement.

    - Standalone ECU Installation & Tuning

    - Horsepower Measurement

    - Dyno Rental

    & More!

    See More Tuning
  • Automotive wiring harness with multiple connectors and cables.

    Motorsport wiring harnesses


    We design and build wiring solutions that keep your car reliable, consistent, and race ready. From full motorsport-grade harnesses built to withstand the harshest conditions, to cost-friendly options that integrate seamlessly with your factory wiring. Every harness is tailored to your build, budget, and goals.

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An engine management unit labeled 'EMU Black' with multiple electrical wiring harnesses arranged around it.

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