Why does the factory GT-R reserve tank cause overheating issues during track use?

The factory tank's limited capacity makes it prone to cavitation after sustained full-throttle driving, and cavitation accelerates coolant temperature rise, which is the specific problem Top Secret's larger tank was designed to solve.

Does the larger capacity alone solve the overheating problem, or is there more to it?

Capacity is only part of it; Top Secret also redesigned the tank's internal structure, and that internal redesign is what actually suppresses the overheating tendency rather than volume by itself.

How do I check coolant level with this tank without opening it?

The tank includes a built-in level gauge, so coolant level can be checked visually at a glance instead of removing the cap to look inside.

Is there a functional difference between the buffed and gold anodized finish options, or is it purely cosmetic?

The finish choice is cosmetic; both the buffed aluminum and gold anodized aluminum versions use the same 2.3-liter capacity and internal structure, so the decision comes down to appearance under the hood.

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Description

Top Secret Reserve Tank for R35 Nissan GT-R

The Top Secret R35 GT-R reserve tank exists to fix a real problem with the factory setup: the stock tank’s small capacity leaves it prone to cavitation after sustained full-throttle runs, and once cavitation starts, coolant temperature climbs fast. Top Secret addressed it by building a 2.3-liter aluminum tank, larger than even Nissan’s own SPEC-V unit, and redesigning the internal structure rather than just scaling up the stock tank’s shape. That internal redesign is what actually suppresses the overheating tendency, not just the added volume alone. It comes with a level gauge built in, so checking coolant level is a glance instead of pulling a cap mid-session. It’s available in a buffed aluminum or a gold anodized finish, depending on what you’re running under the hood.

Features

2.3-liter capacity (larger than Nissan’s factory SPEC-V reserve tank)
Redesigned internal structure
Reduces coolant temperature rise under sustained load
Addresses cavitation caused by the factory tank’s limited capacity during full-throttle driving
Built-in level gauge for at-a-glance coolant level checks
Available in buffed aluminum or gold anodized aluminum finish

Specifications

Capacity: 2.3L
Material: Aluminum
Finish Options:
- Buffed aluminum
- Gold anodized aluminum

Applications

Nissan GT-R: CBA-R35, DBA-R35, EBA-R35, 4BA-R35 | 2008-2025

Frequently Asked Questions

Why does the factory GT-R reserve tank cause overheating issues during track use? The factory tank’s limited capacity makes it prone to cavitation after sustained full-throttle driving, and cavitation accelerates coolant temperature rise, which is the specific problem Top Secret’s larger tank was designed to solve.
Does the larger capacity alone solve the overheating problem, or is there more to it? Capacity is only part of it; Top Secret also redesigned the tank’s internal structure, and that internal redesign is what actually suppresses the overheating tendency rather than volume by itself.
How do I check coolant level with this tank without opening it? The tank includes a built-in level gauge, so coolant level can be checked visually at a glance instead of removing the cap to look inside.
Is there a functional difference between the buffed and gold anodized finish options, or is it purely cosmetic? The finish choice is cosmetic; both the buffed aluminum and gold anodized aluminum versions use the same 2.3-liter capacity and internal structure, so the decision comes down to appearance under the hood.

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.

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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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