Why is there a separate rear toe arm for the 981/718 generation rather than using the same SPL RTA 996?

The 981 and 982/718 generation Boxster and Cayman use a different rear suspension architecture and different rear toe arm mounting geometry from the older 996, 997, 986, and 987 platforms. The arm attachment points, arm angle, and pivot geometry are different enough that SPL engineers a separate part for each generation. The SPL RTA 996 and SPL RTA 981 are not interchangeable; ordering the wrong version will result in a fitment problem. Confirm your specific platform before ordering.

What geometry problem does lowering the 981 create at the rear toe arm?

The 981's rear multi-link suspension changes the effective geometry of every link as the ride height drops. The rear toe arm, which controls the toe angle through its length and angular position, moves to a geometry it wasn't sized for at the factory; the result is excessive rear toe-in that goes beyond what the factory eccentric bolt can adjust back out. Excessive rear toe-in pushes the handling toward understeer at corner entry, reduces the feel of what the rear is doing, and wears the inside rear tire shoulder unevenly. The SPL RTA 981's extended adjustment range provides the range needed to bring toe back to the correct target at the lowered height.

What is FEA validation and why does it matter for this arm?

Finite Element Analysis is a computational method that simulates how a structure behaves under load by dividing it into thousands of small elements and calculating the stress at each point. SPL uses FEA during the design phase to confirm that the arm's geometry and gun-drilled weight reduction do not create stress concentrations or failure points under the loads the arm experiences in use. The FEA validation step means the weight reduction is confirmed safe across all load cases before the first part is produced.

Does installing the SPL RTA 981 also reduce dynamic toe change through bump travel?

Yes. The factory rear toe arm uses a rubber bushing that deflects under lateral and longitudinal loads; this allows the arm to move slightly away from its set position as the suspension loads up, introducing dynamic toe change mid-corner. The FK spherical rod ends in the RTA 981 articulate freely without deflecting, holding the toe arm in position under all load conditions. The toe set at the alignment rack holds throughout the suspension's travel range; both static alignment accuracy and dynamic geometry consistency improve simultaneously.

Are replacement rod ends available for the SPL RTA 981?

Yes. SPL Parts offers replacement rod ends for the RTA 981 in both left and right hand thread.

Description

Additional Info

Shipping policy

BP PRICING DIFFERENCE

Reviews

Product Inquiry

Description

SPL Parts Adjustable Bumpsteer Rear Toe Arms for 98x Porsche Boxster / Cayman

The rear suspension on the Porsche 981 Boxster and Cayman uses a multi-link architecture with rear toe arms that control toe angle through an eccentric bolt adjustment. At factory ride height and factory geometry, those rear toe arms have enough travel to align the car within Porsche’s tolerance. Lower the car, and the geometry shifts — the rear toe arms’ effective length changes relative to the new suspension position, and the result is too much toe-in that the factory eccentric can no longer adjust out. Excessive rear toe-in on a lowered 981 or 718 creates real handling problems: the rear end pushes at corner entry, the steering feel becomes indirect, and the inside rear tire shoulder wears faster than it should. The SPL RTA 981 rear toe arms give the alignment technician the full range of adjustment needed to set rear toe correctly at any ride height, along with the structural capability to hold that setting under load. Gun-drilled 2024-T351 aluminum main links reduce unsprung weight while maintaining the high strength and stiffness required of rear toe arms in demanding use — the arm geometry was developed using Computer Aided Design validated by Finite Element Analysis, confirming structural performance across all load cases before production. The 360-degree rotating clamp locks the toe setting with a single allen key, without jam nuts, quickly and repeatably.

Features

Extended rear toe adjustment range beyond the factory eccentric bolt; corrects the excessive rear toe-in that lowering the 981 or 718 introduces beyond the factory rear toe arms’ capacity
Gun-drilled 2024-T351 aluminum main links; black anodized; gun-drilling reduces unsprung weight while maintaining structural integrity
Computer Aided Design validated by Finite Element Analysis; structural performance of the rear toe arms confirmed across all load cases before production
SPL exclusive 360-degree rotating clamp; locks toe setting without jam nuts; single allen key adjustment
High-misalignment three-piece Teflon-lined FK Heim joints and rod ends; eliminates rubber bushing deflection; rear toe arms hold their set position under all load conditions
Suitable for daily driver through race car use

Specifications

Body Material: 2024-T351 aluminum (gun-drilled, black anodized)
Heim Joints: PTFE-lined FK USA spherical bearings
Toe Adjustment: Wide range — past OEM eccentric limits
Bumpsteer Adjustment: Up to 0.5″
Origin: Made in the USA

Applications

Porsche Boxster: 981, 982 | 2013-present
Porsche Boxster GTS: 981, 982 | 2014-present
Porsche Boxster Spyder: 981 | 2015-2016
Porsche Boxster S: 981, 982 | 2013-present
Porsche Boxster T: 982 | 2019-present
Porsche Cayman: 981, 982 | 2013-present
Porsche Cayman GT4: 981, 982 | 2015-present
Porsche Cayman GT4 RS: 982 | 2021-present
Porsche Cayman GTS: 981, 982 | 2015-present
Porsche Cayman S: 981, 982 | 2013-present
Porsche Cayman T: 982 | 2019-present
Porsche Cayman R: 981 | 2013-2016

Notes

Installation Instructions
Replacement rod ends available from SPL Parts in left and right hand thread, please contact us
SPL components are made-to-order in the USA; build time will be confirmed at the time of order

Frequently Asked Questions

Why is there a separate set of rear toe arms for the 981/718 generation rather than using the same SPL RTA 996? The 981 and 982/718 generation Boxster and Cayman use a different rear suspension architecture and different rear toe arm mounting geometry from the older 996, 997, 986, and 987 platforms. The arm attachment points, arm angle, and pivot geometry are different enough that SPL engineers a dedicated set of rear toe arms for each generation. The SPL RTA 996 and SPL RTA 981 rear toe arms are not interchangeable; ordering the wrong version will result in a fitment problem. Confirm your specific platform before ordering.
What geometry problem does lowering the 981 create at the rear toe arms? The 981’s rear multi-link suspension changes the effective geometry of every link as ride height drops. The rear toe arms, which control the toe angle through their length and angular position, move to a geometry they weren’t sized for at the factory — the result is excessive rear toe-in that goes beyond what the factory eccentric bolt can adjust back out. Excessive rear toe-in pushes the handling toward understeer at corner entry, reduces the feel of what the rear is doing, and wears the inside rear tire shoulder unevenly. The SPL RTA 981 rear toe arms provide the extended adjustment range needed to bring toe back to the correct target at any lowered ride height.
What is FEA validation and why does it matter for these rear toe arms? Finite Element Analysis is a computational method that simulates how a structure behaves under load by dividing it into thousands of small elements and calculating the stress at each point. SPL uses FEA during the design phase to confirm that the rear toe arms’ geometry and gun-drilled weight reduction do not create stress concentrations or failure points under the loads the arms experience in use — hard cornering, braking, and sustained track loading. The FEA validation step means the weight reduction built into the rear toe arms is confirmed safe across all load cases before the first part is produced.
Does installing the SPL RTA 981 rear toe arms also reduce dynamic toe change through bump travel? Yes. The factory rear toe arms use a rubber bushing that deflects under lateral and longitudinal loads, allowing the arms to move slightly away from their set position as the suspension loads up and introducing dynamic toe change mid-corner. The FK spherical rod ends in the RTA 981 rear toe arms articulate freely without deflecting, holding the arms in position under all load conditions. The toe set at the alignment rack holds throughout the suspension’s travel range — both static alignment accuracy and dynamic geometry consistency improve simultaneously.
Are replacement rod ends available for the SPL RTA 981 rear toe arms? Yes. SPL Parts offers replacement rod ends for the RTA 981 rear toe arms in both left and right hand thread. Please contact the Bulletproof Sales Team for the correct replacement for your specific application.

About SPL Parts

SPL Parts is a USA-based manufacturer of high-performance suspension components engineered for both professional racing and demanding street applications. Built on the core principles of strength, lightweight construction, low friction, and precision, SPL Parts products deliver the adjustability and alignment performance required by top race teams and discerning enthusiasts alike. Every component is produced using USA-sourced, certified materials and machined by experienced local shops to exacting tolerances. Professional TIG welders ensure maximum weld integrity, while each part is hand-fitted and treated with anti-seize and 3M internal panel coating for lasting protection. SPL Parts conducts all research and development in-house, allowing the team to leverage firsthand product knowledge and deliver unmatched customer support. Their suspension components feature innovative adjuster designs for quicker, more precise alignments, and utilize spherical bearings with Teflon liners that are self-cleaning, self-lubricating, and built for long service life. From concept to assembly, SPL Parts is made with pride in the USA by skilled machinists and welders who are committed to quality, innovation, and performance.

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.

Reviews

There are no reviews yet.

Only logged in customers who have purchased this product may leave a review.

Product Inquiry

First Name (*required)

Last Name (*required)

Your E-Mail (*required)

Telephone Number (*required)

Country (*required)

Vehicle Year / Make / Model (*required)

Please Explain What do you want to do with your vehicle

Additional Information (optional)

I agree to the terms & conditions and privacy policy and to have Bulletproof Automotive LLC contact me for promotion, marketing and other purposes via email, phone or SMS message.

SPL Parts Adjustable Bumpsteer Rear Toe Arms for 98x Porsche Boxster / Cayman [SPLRTA981]

Guaranteed Safe Checkout

SPL Parts Adjustable Bumpsteer Rear Toe Arms for 98x Porsche Boxster / Cayman

Features

Specifications

Applications

Notes

Frequently Asked Questions

About SPL Parts

Reviews