HKS Performance Parts: What J-Spec Stocks and Who It's For

HKS has been designing and manufacturing performance parts for Japanese engines since 1973. That is over 50 years of engineering specifically for the platforms J-Spec Garage serves — 2JZ-GTE, RB26DETT, SR20DET, and the broader JDM catalog. HKS is not a brand that dabbles in this space. It is one that helped define it.

This guide covers what HKS makes and what J-Spec Garage currently stocks from their catalog.

Who Is HKS?

HKS — short for Hasegawa, Kitagawa, and Sports — was founded in Fujinomiya, Japan in 1973. The company began with performance exhaust systems and expanded into turbochargers, intercoolers, suspension, camshafts, and engine management. For JDM enthusiasts, HKS occupies a specific position in the market: a Japanese brand that designs parts specifically for Japanese OEM engines, not universal components adapted to fit. That distinction matters when you're fitting suspension to a JZA80 Supra or a Nissan Skyline GT-R.

HKS has an extensive motorsport history — GT turbos used in JGTC and Super GT competition, EVC boost controllers as standard equipment in time attack builds, and suspension systems developed alongside professional drivers in Japan. That motorsport-derived development philosophy shows up in every product they make.

HKS Hipermax R Coilovers — What J-Spec Stocks

The product J-Spec Garage most commonly sells from the HKS catalog is the Hipermax R coilover system. The Hipermax R is HKS's premium street and track coilover — adjustable ride height and damping, engineered with input from HKS's motorsport program, and available in application-specific kits for JDM platforms.

J-Spec currently stocks the HKS Hipermax R in three vehicle-specific configurations:

• HKS Hipermax R Full Kit — Toyota Supra JZA80 — the complete coilover kit for the MK4 Supra. Designed specifically for the JZA80 chassis with spring rates appropriate for street and track use. One of the most widely used suspension upgrades on the MK4 Supra platform.
• HKS Hipermax R Full Kit — Nissan S15 — the S15 Silvia application. Correct spring rates and damper tuning for the S-chassis in street, track, and drift configurations.
• HKS Hipermax R Full Kit — Nissan GT-R R35 — the R35 application. The VR38DETT-powered GT-R requires a significantly different spring rate profile than the older platforms; HKS tunes the Hipermax R specifically for the R35's weight and AWD architecture.

The Hipermax R competes with Tein, KW, and BC Racing at the premium end of the coilover market. HKS's advantage is the motorsport development history and the fact that rates are tuned specifically for each platform rather than using a universal spring and damper with a vehicle-specific mount kit.

HKS Toyota GR Supra (A90) Parts

J-Spec stocks several HKS products for the A90 Toyota GR Supra — the B58-powered fifth-generation car. These are separate from the JZA80 (2JZ) catalog.

• HKS Toyota Supra A90 Adjustable Spring Kit — an HKS-spec lowering spring kit for the A90 GR Supra. Lowers ride height while maintaining a street-appropriate spring rate. A popular entry-level suspension upgrade for A90 owners who want improved handling without committing to a full coilover conversion.
• HKS A90 Supra Carbon Brace — Full Set, Front Set, and Rear Set — carbon fiber strut brace systems for the A90 GR Supra. HKS designs these as structural reinforcement for the A90's engine bay and chassis, reducing body flex and improving handling response.

HKS Filter Elements

J-Spec stocks the HKS 2-Layer Wet Replacement Filter Element (200mm, Red) — a high-flow replacement filter for HKS intake and filtration applications. Compatible with HKS intake systems running the 200mm filter size. A necessary service item for HKS intake-equipped builds.

HKS Products J-Spec Can Source on Request

HKS makes a significantly broader catalog than what J-Spec keeps in stock — including GT turbos for the 2JZ and RB26, camshafts, the SSQV blow-off valve, the FlashEditor ECU tuning tool, and exhaust systems. If you are looking for a specific HKS product not listed in the J-Spec catalog, contact us — we source HKS parts on request for customers who need items from outside our standard stocking list.

Frequently Asked Questions

Is HKS a good brand?

Yes. HKS is one of the most established performance parts manufacturers in Japan, with over 50 years of development history on JDM platforms. Their products are engineered specifically for the engines and chassis they support, not adapted from universal applications. The Hipermax R coilovers in particular represent genuine motorsport-derived suspension development — not a commodity product with HKS badges.

What is the difference between HKS Hipermax R and cheaper coilover alternatives?

The main differences are damper tuning and spring rate specificity. HKS tunes the Hipermax R dampers with input from their professional motorsport program and develops application-specific spring rates for each platform rather than adapting universal rates. Cheaper alternatives often use similar hardware with less development behind the rate curves and damper valving. On a JZA80 Supra or R35 GT-R — cars where suspension geometry is a significant performance variable — this development work is reflected in the on-track behavior.

Can J-Spec source HKS turbos, cams, or other engine parts not listed in the catalog?

Yes. Contact us with the specific HKS part number or description and we can source it. Lead times vary by product and availability — some items ship from US distribution, others require direct Japan import.

Does HKS make parts for the 13B rotary?

HKS does have some rotary applications in their catalog, though their rotary-specific offerings are narrower than their piston engine lineup. For FD and FC RX-7 performance parts, J-Spec's catalog — including RaceOnly billet components as the only authorized US distributor — covers more ground. Browse 13B rotary parts at J-Spec Garage.

Browse the complete HKS collection at J-Spec Garage. Price match guarantee on all stocked items. Contact us for HKS products not currently listed.