What problem do rear side diffusers solve on the R35 GT-R?

The factory R35 body sides do not manage the airflow running underneath the car at speed. That air separates along the body sides, creates drag, and reduces lateral stability in a straight line. The Top Secret carbon rear side diffusers GT-R address that by streamlining the airflow path along the underside of the body, reducing separation and producing the stability effect that keeps the car composed from street speeds through to circuit use above 300 km/h.

How noticeable is the stability improvement at street speeds versus track speeds?

Top Secret describes the improvement as effective from low-speed street driving through to speeds exceeding 300 km/h, which is a wider effective range than most aero components deliver. At street speeds the effect is subtle but present; at circuit and high-speed road speeds where underbody airflow is moving fast enough to generate meaningful aerodynamic forces, the stability gain becomes more pronounced and directly affects how confidently the car can be driven in a straight line.

Is this a racing-only part or is it practical for a street-driven R35?

It is practical for both. Top Secret has run this part on their own GT-R since the R35's release across a range of driving conditions, and they describe it as effective at street speeds as well as on circuit. The carbon construction adds no meaningful weight penalty, and the aerodynamic benefit at road speeds is a genuine improvement rather than a track-only effect.

Do rear side diffusers affect handling through corners or only in a straight line?

The primary function is straight-line stability through underbody airflow management along the body sides. The lateral stability improvement that comes from reducing airflow separation also contributes to how composed the car feels entering and exiting corners at speed, but the design is specifically aimed at straight-line behavior rather than cornering downforce, which is addressed by other aero components.

How do these diffusers interact with other Top Secret aero components on the R35?

Top Secret designs their aero components to work as a system. The rear side diffusers manage airflow along the body sides, which complements the front end aerodynamic work done by components like the V1 front bumper kit and front diffuser. Running the full aero package gives a more coherent overall airflow management solution than any single component delivers on its own.

Description

Additional Info

Shipping policy

BP PRICING DIFFERENCE

Reviews

Product Inquiry

Description

Top Secret Carbon Rear Side Diffusers for CBA-R35 Nissan GT-R

The Top Secret carbon rear side diffusers GT-R owners running the car at speed need to address the underbody airflow that builds instability on the sides of the car are a direct application of racing car aerodynamic design to the R35 platform. The factory body side does nothing to manage airflow running underneath the car at speed; it separates, creates drag, and contributes to the instability that becomes noticeable from highway speeds through to circuit use. These diffusers streamline that airflow along the body sides, reducing separation and generating the lateral stability that keeps the car predictable in a straight line from low-speed street driving through to speeds exceeding 300km/h. Top Secret has run this part on their own GT-R since the R35’s release and considers it one of the more effective aero components in their lineup for the consistency of the stability improvement it delivers across the full speed range. Full carbon construction.

Features

Streamlines underbody airflow along the body sides to improve straight-line stability
Effective from low-speed street driving through to speeds exceeding 300km/h
Racing-derived design
Combines aerodynamic function and visual presence
Full carbon construction
Run by Top Secret on their own GT-R since the R35’s release
Sold as a pair

Applications

Nissan GT-R: CBA-R35 | 2008-2011

Notes

Sold as a pair
All Top Secret carbon is delivered in its raw state and will require prep and application of a UV resistant clear coat and/or PPF

Frequently Asked Questions

What problem do rear side diffusers solve on the R35 GT-R? The factory R35 body sides do not manage the airflow running underneath the car at speed. That air separates along the body sides, creates drag, and reduces lateral stability in a straight line. The Top Secret carbon rear side diffusers GT-R address that by streamlining the airflow path along the underside of the body, reducing separation and producing the stability effect that keeps the car composed from street speeds through to circuit use above 300 km/h.
How noticeable is the stability improvement at street speeds versus track speeds? Top Secret describes the improvement as effective from low-speed street driving through to speeds exceeding 300km/h, which is a wider effective range than most aero components deliver. At street speeds the effect is subtle but present; at circuit and high-speed road speeds where underbody airflow is moving fast enough to generate meaningful aerodynamic forces, the stability gain becomes more pronounced and directly affects how confidently the car can be driven in a straight line.
Is this a racing-only part or is it practical for a street-driven R35? It is practical for both. Top Secret has run this part on their own GT-R since the R35’s release across a range of driving conditions, and they describe it as effective at street speeds as well as on circuit. The carbon construction adds no meaningful weight penalty, and the aerodynamic benefit at road speeds is a genuine improvement rather than a track-only effect.
Do rear side diffusers affect handling through corners or only in a straight line? The primary function is straight-line stability through underbody airflow management along the body sides. The lateral stability improvement that comes from reducing airflow separation also contributes to how composed the car feels entering and exiting corners at speed, but the design is specifically aimed at straight-line behavior rather than cornering downforce, which is addressed by other aero components.
How do these diffusers interact with other Top Secret aero components on the R35? Top Secret designs their aero components to work as a system. The rear side diffusers manage airflow along the body sides, which complements the front end aerodynamic work done by components like the V1 front bumper kit and front diffuser. Running the full aero package gives a more coherent overall airflow management solution than any single component delivers on its own.

About Top Secret

Top Secret Co., Ltd. (株式会社トップシークレット, Kabushiki-gaisha Toppu Shīkuretto) is a renowned Japanese automobile tuner and parts manufacturer, founded by automotive engineer and driver Kazuhiko “Smokey” Nagata. The company is widely recognized for its expertise in tuning, aftermarket parts, body kits, and performance engineering. Top Secret’s product range includes aero components, exterior and interior parts, engine upgrades, exhaust systems, chassis, brakes, suspension, and powertrain enhancements. In addition to its products, Top Secret is also famous for its high-speed Wangan runs, as well as its involvement in professional drifting, circuit racing, and drag racing.

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

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.