RaceOnly Parts in the USA: J-Spec Garage Is Your Only Source
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Finding quality billet CNC rotary engine parts in the United States has always been a frustrating exercise. You either settle for mass-market components that weren't engineered for your power goals, or you spend weeks sourcing overseas with no certainty on quality, fitment, or lead time. For serious 13B-REW and 20B-REW builds, that gap has been real — until now.
J-Spec Garage is the only authorized US distributor of RaceOnly parts. That means one domestic source, stocked and ready to ship, backed by a team that actually builds rotary-powered cars.
What Is RaceOnly?
RaceOnly is a precision engineering brand that designs and manufactures billet CNC components specifically for rotary engines — the Mazda 13B-REW, 20B-REW, and the broader FD RX-7 and FC RX-7 platform. This isn't a generalist parts catalog. Every RaceOnly product is engineered for a specific rotary application, with tolerances and material specs that match what the platform demands at elevated power levels.
The manufacturing standard is billet aluminum — not cast, not stamped. CNC-machined from solid stock, which means consistent wall thickness, precise port geometry, and surface finishes that hold up under the heat cycling and mechanical stress a built rotary generates. RaceOnly parts are designed for street builds that see track days, dedicated circuit cars, and full drag builds where every component in the fueling and intake path has to perform without question.
What separates RaceOnly from generic aftermarket options is specificity. A 13B-REW secondary fuel rail isn't a universal fuel system component with a bracket kit bolted on — it's a part engineered around the twin-rotor architecture, the OEM port layout, and the injector sizing a built engine requires. That level of platform-specific development is what makes RaceOnly parts worth sourcing, and worth the effort to find.
Why J-Spec Garage Is Your Only US Source
J-Spec Garage holds the exclusive US distribution rights for RaceOnly. That word — exclusive — matters here. You will not find RaceOnly parts through another US retailer, and you should be skeptical of any gray-market listing that claims otherwise. Gray-market imports carry no warranty support, no guaranteed authenticity, and no recourse if a part arrives damaged or incorrect.
When you order RaceOnly parts from J-Spec Garage, you're buying from the authorized channel. That means:
- Direct domestic inventory — no waiting 3–6 weeks for overseas fulfillment. Parts are in stock at our Panama City Beach, FL facility and ship fast.
- Authentic product — every RaceOnly component we sell is sourced directly from the manufacturer.
- Rotary expertise behind every order — our team understands the 13B-REW platform, which means if you have a fitment or compatibility question, you're talking to someone who knows the engine, not a generic customer service rep reading off a spec sheet.
- Price match guarantee — if you find a legitimate competitor price, we'll match it.
For FD RX-7 builders in the US, there is no other option for RaceOnly. We're it.
Key RaceOnly Products
The RaceOnly catalog covers several critical systems on the 13B-REW and FC/FD rotary platform. Here's what to know about the core product categories available through J-Spec:
Secondary Fuel Rail Step-Up Kits
The RaceOnly FD 13B-REW secondary rail step-up kit is one of the most specified RaceOnly products in the US market. On a built 13B-REW running larger primary injectors and higher fuel pressure, the OEM secondary fuel rail becomes a restriction point — both in flow capacity and in fitment compatibility with larger injector bodies. The RaceOnly step-up kit resolves this with a machined billet rail designed for the secondary injector bank, giving you the clearance and flow capacity a built engine needs without fabricating a custom solution. If you're doing a serious FD RX-7 engine build, this is the part that makes your fuel system work as a cohesive unit rather than a collection of mismatched components.
Intake Manifold Components
The 13B-REW intake manifold system — with its sequential intake architecture and dual throttle bodies — is one of the most complex factory intake setups ever put on a production sports car. RaceOnly engineers billet components that integrate with and improve on that system, designed for builds that are pushing the OEM intake layout past its intended operating range. Whether you're porting, building a single-turbo conversion, or optimizing the intake charge path on a twin-turbo build, RaceOnly's manifold components give you machined precision where the OEM casting leaves room for improvement.
Oil and Coolant System Fittings
Rotary engines are sensitive to oil temperature management in a way that piston engines simply aren't. The apex seal lubrication and the thermal load on the rotor housings mean that oil system integrity isn't a supporting-mod consideration — it's foundational. RaceOnly produces billet fittings and adapters for the 13B-REW oil and coolant circuit that eliminate the leak points and flow restrictions that plague modified rotary oil systems. For any 13B rotary build pushing beyond stock power levels, this hardware is part of a reliable foundation, not an optional upgrade.
Billet CNC Accessories
Beyond the primary systems, RaceOnly produces a range of billet CNC accessories for the FD and FC platform — brackets, block-off plates, sensor bungs, and hardware that rounds out a build done to a high standard. These are the parts that separate a build that looks finished from one that actually is. Small in cost relative to the overall build, significant in the difference they make to reliability and presentation.
Who Should Buy RaceOnly Parts?
RaceOnly is not entry-level rotary hardware. These parts are engineered for builders who are doing the job properly — which means they're exactly right for:
- FD RX-7 owners doing a serious rebuild — if you're pulling the engine to address wear, you're already in the right place to upgrade the fuel and intake systems properly. Drop in RaceOnly components while everything is apart and don't revisit it.
- 13B-REW builders targeting 400+ whp — at this power level, OEM fuel system components become a liability. RaceOnly's secondary rail and fueling hardware is engineered for the injector sizing and fuel pressure these builds require.
- Track and time attack builds — precision components that hold their tolerances under thermal and mechanical stress are not optional when the car is running hard. RaceOnly's manufacturing standard is built for exactly this use case.
- FC RX-7 rotary builds — the FC platform with a 13B-REW swap or a built 13B-T benefits from the same RaceOnly component philosophy. The rotary-specific engineering approach applies across the platform.
- Builders who want to do it once — RaceOnly parts are priced like precision components and perform like them. If you're building the engine to last, the cost of proper hardware is always less than the cost of doing the build twice.
How to Order RaceOnly Parts from J-Spec Garage
Ordering is straightforward. Browse the full RaceOnly collection at J-Spec Garage to see what's currently in stock. Inventory moves — RaceOnly is a specialized catalog and demand among serious FD builders is consistent — so if you see a part you need, don't wait on it.
If you're building a parts list and need help confirming compatibility for your specific setup, reach out. Our team knows the 13B-REW platform and can help you identify what you need for your build goals before you order. We also carry the broader Mazda RX-7 engine parts catalog and 13B rotary parts collection — so whether you're sourcing RaceOnly exclusively or building a complete parts list for the whole engine, J-Spec is the one-stop shop for the rotary platform in the US.
Price match guarantee applies across the board. If you find a legitimate price on any part we carry, we'll match it — no hoops.
The Bottom Line
Serious rotary builds in the US now have a single authoritative source for RaceOnly precision billet components. J-Spec Garage is the only authorized US distributor — not a gray-market importer, not a third-party reseller. Direct inventory, domestic shipping, rotary expertise, and price match backing every order.
Browse the full RaceOnly collection at J-Spec Garage and get your build spec'd with the right parts from the only US source that can actually sell them to you.
RaceOnly USA: Frequently Asked Questions
Where can I buy RaceOnly parts in the USA?
J-Spec Garage is the only authorized US distributor of RaceOnly. Genuine RaceOnly billet rotary parts are not available through any other US retailer — J-Spec stocks them domestically in Panama City Beach, Florida and ships fast within the US.
Is J-Spec Garage an authorized RaceOnly distributor?
Yes. J-Spec Garage holds exclusive US distribution rights for RaceOnly. Any other US listing claiming to sell RaceOnly is gray-market, with no warranty support and no guaranteed authenticity.
What does RaceOnly manufacture for the rotary platform?
RaceOnly designs billet CNC components for the 13B-REW and 20B-REW: secondary fuel rail step-up kits, intake manifold components, oil and coolant system fittings, IGN-1A coil kits and harnesses, billet oil filter pedestals, and a range of billet accessories for the FD and FC RX-7.
Are RaceOnly parts made from billet aluminum?
Yes. Every RaceOnly component is CNC-machined from solid billet aluminum — not cast or stamped — for consistent wall thickness, precise port geometry, and surface finishes that hold up to the heat cycling and mechanical stress a built rotary generates.
Do RaceOnly parts fit the FC RX-7 as well as the FD?
RaceOnly's primary development platform is the FD RX-7 and the 13B-REW, where the catalog is deepest. FC-specific parts are more limited but available. If a US-available RaceOnly part exists for your RX-7, J-Spec Garage carries it.
How fast does J-Spec Garage ship RaceOnly parts?
Because J-Spec Garage stocks RaceOnly domestically at its Panama City Beach, Florida facility, orders ship fast from within the US with no 3-6 week overseas fulfillment wait. A price match guarantee applies across the catalog.
