Can the NTR-R1 be upgraded to a higher specification later without replacing the whole kit?

Yes. The Nitron NTR-R1 coilover kit for the G29 Z4 and A90 GR Supra is fully upgradeable. The modular construction means damper internals, valving, and spring rates can be revised as your build evolves, whether that means stepping up to R3 specification or moving from a fast road to a track day setup without starting from scratch.

How does a kit built without a remote canister manage heat and fade on track?

The NTR-R1 uses an internal reservoir design with nitrogen gas charging to control heat and maintain consistent damping under sustained load. The ultra-low friction component construction reduces heat generation at the shaft and seal, and the fade-resistant valving is developed from the same platform Nitron uses in professional race builds rather than adapted from a road-only design.

What does fully serviceable mean in practice for a street and track-driven car?

It means the damper can be rebuilt, revalved, and re-sprung by Nitron rather than replaced when it reaches the end of its service life. Seals, oil, and shim stacks can all be refreshed, and spring rates can be changed at the same time if the build direction has shifted. For a car that sees regular track use, that serviceability is what makes the long-term cost of ownership reasonable.

Is the NTR-R1 suitable as a starting point for a car that will eventually be built further?

Yes. The NTR-R1 sits at the entry point of the NTR range but shares core components with the R3 system, so it performs well beyond what the price point suggests. The kit is custom sprung to order, fully serviceable, and upgradeable, which makes it a sensible foundation for a build that will develop over time rather than a compromise to be replaced in the first season.

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Description

Nitron NTR-R1 Coilover Kit for G29 BMW Z4 / A9x Toyota GR Supra

The Nitron NTR-R1 coilover kit for the G29 BMW Z4 and A9x Toyota GR Supra addresses a familiar problem on both platforms: factory suspension calibrated for a broad range of drivers rather than the precision a serious build demands. Both cars share the same underlying architecture, and Nitron has engineered this kit to suit both, with coilover and divorced rear suspension configurations available to cover different build requirements across the Z4 and GR Supra. The damping hardware is drawn directly from Nitron’s R3 race platform, sharing core components with a kit built for professional competition, and combined 2-way adjustment keeps setup straightforward without requiring a remote canister to package around. Every unit is individually hand-built with ultra-low friction components that deliver consistent, fade-resistant performance from the street to the circuit. Hard-anodized titanium finish parts and high-grade materials keep corrosion out and weight in check, and with each kit custom built, custom sprung, and fully serviceable, the NTR-R1 is an investment that holds up well beyond a single season.

Coilover vs Divorced Rear Suspension

The G29 Z4 NTR-R1 is available with two rear suspension configurations depending on how the car is being built. The coilover setup combines the spring and damper into a single unit, keeping things compact and straightforward for road and general track use. The divorced configuration separates the spring and damper, allowing each to be positioned and tuned independently; this is the preferred approach for dedicated race builds where maximizing suspension geometry and setup flexibility matters more than packaging simplicity. Nitron offers both to make sure the R1 works with the build rather than against it.
The A90 and A91 GR Supra NTR-R1 are available in the divorced rear suspension configuration only. The divorced setup separates the spring and damper, allowing each to be positioned and tuned independently rather than packaging both into a single coilover unit. This suits the GR Supra’s rear suspension geometry and gives dedicated builds the setup flexibility to extract the most from the platform without compromising damper positioning or spring rate tuning.

Unique Technology

Every Nitron shock is built from precision components that go through a thorough design and development process before reaching final assembly. The modular construction gives engineers the flexibility to approach each application properly, without compromising on how individual parts are made or how they perform together under load. Components are machined to tight tolerances and inspected one by one by trained technicians throughout production, not just at the end. New materials, finishes, and processes are validated extensively before adoption, with proprietary Nitron technologies integrated throughout to produce shocks that consistently hold up against the competition on road and track. That engineering standard is what the brand has been built on since 1998.
- Basic Damper Design:
  1. End Eye / Top Mount
  2. Damper Piston & Shim Stack
  3. Shaft / Rod
  4. Floating / Separator Piston
  5. Suspension Oil
  6. Compressed Nitrogen Gas

Bespoke Engineering

Nitron doesn’t adapt a generic damper to fit the G29 Z4 / A9x GR Supra. Every application goes through a dedicated development process, with components, spring rates, and damping characteristics engineered around the specific platform rather than the category it belongs to. Geometry, weight distribution, and suspension travel are factored into the design from the start, not compensated for after the fact. The result is a kit built for the G29 Z4 or A9x GR Supra specifically, not one that was built broadly and happens to fit.

Features

Coilover or divorced rear suspension types
Internal reservoir type
2-way combined adjustment
Full alloy body
Preload adjuster
Combined 24 clicks of adjustment
Nitrogen gas charged
Precision bearing spacers supplied as required
Consists of 4 coilover assemblies, and top mounts
Hand made to order

Specifications

Coilover Type: NTR-R1
Adjustment Type: 2-way combined
Adjustment: 24 clicks combined
Rear Suspension Types:
- G29 Z4:
  - Coilover
  - Divorced
- A90 / A91 GR Supra:
  - Divorced
Droplinks Included: No
Recommended Spring Rates:
- G29 Z4:
  - FRS – Fast Road Spec:
    - Front: 343lbs/inch (60N/mm)
    - Rear:
      - Coilover: 300lbs/inch (53N/mm)
      - Divorced: 799lbs/inch (140N/mm)
- A90 / A91 GR Supra:
  - FRS – Fast Road Spec:
    - Front: 343lbs/inch (60N/mm)
    - Rear: 799lbs/inch (140N/mm)
  - TDS – Track Day Spec:
    - Front: 457lbs/inch (80N/mm)
    - Rear: 913lbs/inch (160N/mm)

Applications

BMW Z4 M40i: G29 | 2019-2026
BMW Z4 sDrive20i: G29 | 2019-2026
BMW Z4 sDrive30i: G29 | 2019-2026
Toyota GR Supra: A90, A91, MK5 | 2020-2026

Other Suspension Kits for G29 Z4 / A9x GR Supra

NTR-R1 Coilover Kit w/ Standalone FAL (A90 / A91 GR Supra only)
NTR-R3 Coilover Kit
NTR-R3 Coilover Kit w/ Standalone FAL (A90 / A91 GR Supra only)
elec-TRON R1 Coilover Kit
elec-TRON R1 Coilover Kit w/ Standalone FAL (A90 / A91 GR Supra only)
elec-TRON R3 Coilover Kit
elec-TRON R3 Coilover Kit w/ Standalone FAL (A90 / A91 GR Supra only)

Notes

Compatible on 2.0L and 3.0L GR Supra models
If your Z4 or GR Supra is equipped with electronic damping, the Nitron Electronic Damping Delete Kit is required when fitting a non-electronic coilover kit to prevent fault codes and warning lights
Custom spring rates also available, please contact us directly here for more information or for a consultation on custom rates
Images used for illustration purposes only. Specific details, finishes and end fittings may differ from that shown.
Precision bearing spacers supplied as required

Frequently Asked Questions

Can the NTR-R1 be upgraded to a higher specification later without replacing the whole kit? Yes. The Nitron NTR-R1 coilover kit for the G29 Z4 and A90 GR Supra is fully upgradeable. The modular construction means damper internals, valving, and spring rates can be revised as your build evolves, whether that means stepping up to R3 specification or moving from a fast road to a track day setup without starting from scratch.
How does a kit built without a remote canister manage heat and fade on track? The NTR-R1 uses an internal reservoir design with nitrogen gas charging to control heat and maintain consistent damping under sustained load. The ultra-low friction component construction reduces heat generation at the shaft and seal, and the fade-resistant valving is developed from the same platform Nitron uses in professional race builds rather than adapted from a road-only design.
What does fully serviceable mean in practice for a street and track-driven car? It means the damper can be rebuilt, revalved, and re-sprung by Nitron rather than replaced when it reaches the end of its service life. Seals, oil, and shim stacks can all be refreshed, and spring rates can be changed at the same time if the build direction has shifted. For a car that sees regular track use, that serviceability is what makes the long-term cost of ownership reasonable.
Is the NTR-R1 suitable as a starting point for a car that will eventually be built further? Yes. The NTR-R1 sits at the entry point of the NTR range but shares core components with the R3 system, so it performs well beyond what the price point suggests. The kit is custom sprung to order, fully serviceable, and upgradeable, which makes it a sensible foundation for a build that will develop over time rather than a compromise to be replaced in the first season.

About Nitron Suspension

Nitron Suspension has been at the forefront of precision suspension engineering since 1998, founded by Guy Evans with the goal of building high-performance shocks for enthusiasts and professionals alike. Over 200 dealers now carry Nitron products across Europe, Asia, the US, Australasia, and Africa. In 2008, the company moved into a dedicated facility in the UK’s Motorsport Valley, adding dynamometers, 5-axis CNC machines, and 3D CAD capabilities to support both growing demand and continued product development. A second expansion came in 2023 with a new office in Murrieta, California. The team behind every Nitron product draws from deep backgrounds in machining, materials technology, hydraulics, bike engineering, and F1 racing, with many engineers bringing firsthand experience as competitive drivers and riders. That depth of knowledge across both the technical and competitive sides of motorsport shapes every product Nitron develops.

Additional Information

The Bulletproof Automotive website contains many thousands of products purchased in multiple different currencies. All of the prices are entered manually and accurately at the time of entry. Due to the consistently fluctuating international exchange rates, at times prices may not be able to be honored at their original intended rate. We apologize for any inconvenience this may cause, unfortunately our website is unable to compensate dynamically for what can at times be volatile changes in the cost of items due to currency values fluctuating, changes in prices from suppliers, changes in shipping and import duties, and other factors. Rest assured that any order you place on line will be at zero risk to you in this area. If in the event your order cannot be fulfilled at the original intended website price we will offer you a 100% refund, no questions asked. We will continue to do our best to maintain updated prices and we will always continue to offer our price match guarantees as well to ensure our prices are always the best for you. In short, prices may change without notice. It is always advised to give us a call prior to placing your order online to confirm availability and to confirm current pricing.

Shipping Policy

Items that are in stock in the US, either at Bulletproof’s warehouse or at a supplier’s warehouse, are generally delivered within 7-10 days. Special order items from overseas take considerably longer. As a courtesy Bulletproof offers delivery estimates to our customers which take into consideration manufacturer availability and shipping schedule. These estimates represent our best guess based on previous orders from the manufacturer and do not in any way imply a guaranteed delivery window. Many manufacturers work in a “just in time” inventory system and often take 2-20+ weeks to produce an item once an order is submitted. All deliverable items are then sent to our Japanese warehouse. Bulletproof ships a minimum of one full ocean freight container every month from Japan, oftentimes more than one a month. Ocean freight takes an average of 4 weeks. Typically it breaks down to one week in Japan for paperwork and customs, two weeks by boat and one week in US customs/clearance. Due to the wide number of variables between manufacturer and shipping schedules, delivery estimates are simply just that – estimates. We attempt to estimate conservatively and we usually deliver faster than our estimates suggest. It is not Bulletproof’s policy to guarantee delivery time of any special order item, this is impossible for us to do. By ordering you acknowledge that there is no required delivery ETA and an order may not be canceled or altered due to manufacturing or shipping delays, all ETA’s are provided as a best guess only. Please review the full Terms & Conditions here.

BP Pricing Difference

We do pricing a little differently on our JDM brands and we believe in making things simple and clear. No hidden fees or surcharges. Every price you see includes the shipping cost to our office in Los Angeles, California and all the associated taxes/duties/fees for bringing the products into the US. The only shipping you ever pay is from our facility in the US to your location. Be wary of resellers that don’t include the cost of international shipping in their pricing on JDM parts. While we believe we’ll always have the lowest all-in price on JDM products, we offer a price match guarantee for all authentic parts purchased from authorized dealers as well. For many international customers, it’s much more affordable to ship from the USA than from Japan directly, as the air freight and ocean freight costs are typically much less. However, for customers looking to ship directly from Japan outside of North America, or domestically in Japan, we can provide pricing specifically for that scenario. Please do not hesitate to contact us with any pricing questions or concerns. Please email us at sales@bulletproofautomotive.com with any inquiries.

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Nitron NTR-R1 Coilover Kit for G29 BMW Z4 / A9x Toyota GR Supra [NTCTO013R1]

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Nitron NTR-R1 Coilover Kit for G29 BMW Z4 / A9x Toyota GR Supra

Coilover vs Divorced Rear Suspension

Unique Technology

Bespoke Engineering

Features

Specifications

Applications

Other Suspension Kits for G29 Z4 / A9x GR Supra

Notes

Frequently Asked Questions

About Nitron Suspension

Reviews