What aerodynamic function does this lip spoiler actually perform on the 370Z?

The Top Secret front lip spoiler Z34 370Z does three things aerodynamically: the integrated brake cooling ducts channel airflow directly to the front brakes during driving, the underbody shaping reduces the front lift the stock bumper generates at speed, and the combined effect produces front downforce that keeps the nose more planted under hard driving. It is not a purely cosmetic addition and the duct integration in particular requires the installation drilling that a visual-only lip would not.

What is the difference between the FRP, half carbon, and full carbon versions?

The FRP version is fiberglass throughout. The half carbon version uses carbon fiber on the top visible surface of the lip while the duct section above the dividing line and the underside are FRP. The full carbon version uses carbon fiber on every component that comes into contact with the brake cooling duct, making it the most weight-optimized and thermally appropriate option for the duct area specifically. All three versions deliver the same aerodynamic and brake cooling function; the differences are material, weight, and price.

Why does installation require drilling holes in the factory bumper?

The brake cooling ducts need to connect through the bumper to direct airflow to the front brakes effectively. Two holes are drilled into the rear face of the factory front bumper to create that connection point. This is a permanent modification to the bumper, which is why Top Secret specifies sheet metal factory installation rather than a general workshop environment. Factor this into the decision if returning the car to stock is a future consideration.

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Description

Top Secret G-Force Front Lip Spoiler for Z34 Nissan 370Z (pre-facelift)

The Top Secret front lip spoiler 370Z pre-facelift owners need to add functional aerodynamic work to the front end is part of Top Secret’s G-Force Aero lineup, a range built around the principle that aero parts need to earn their place through function rather than appearance alone. This lip integrates brake cooling ducts to actively direct airflow to the front brakes, shapes the airflow path under the car to reduce lift, and generates front downforce that improves stability and confidence under hard driving. The design addresses fitment and durability alongside aerodynamic function, which matters on a part that takes road debris, curb strikes, and temperature cycling in normal use. Three material options are available; FRP throughout, half carbon with a carbon fiber top surface and FRP duct section and underside, and full carbon where every component in contact with the brake cooling duct is carbon fiber.

Features

Integrated brake cooling ducts direct airflow to the front brakes
Aerodynamic underbody shaping
Reduces front lift and increases downforce
FRP, half carbon, full carbon material options
Part of Top Secret’s G-Force Aero lineup

Applications

Nissan 370Z: Z34 | 2009-2012

Notes

This lip spoiler fits pre-facelift Z34 370Z models only; it is not compatible with the 2013-2020 facelift 370Z or the NISMO 370Z variant
Installation requires drilling two holes into the rear of the factory front bumper; this modification is permanent
Professional installation by a body shop with panel fabrication experience is required
FRP version is delivered unpainted
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 aerodynamic function does this lip spoiler actually perform on the 370Z? The Top Secret front lip spoiler Z34 370Z does three things aerodynamically: the integrated brake cooling ducts channel airflow directly to the front brakes during driving, the underbody shaping reduces the front lift the stock bumper generates at speed, and the combined effect produces front downforce that keeps the nose more planted under hard driving. It is not a purely cosmetic addition and the duct integration in particular requires the installation drilling that a visual-only lip would not.
What is the difference between the FRP, half carbon, and full carbon versions? The FRP version is fiberglass throughout. The half carbon version uses carbon fiber on the top visible surface of the lip while the duct section above the dividing line and the underside are FRP. The full carbon version uses carbon fiber on every component that comes into contact with the brake cooling duct, making it the most weight-optimized and thermally appropriate option for the duct area specifically. All three versions deliver the same aerodynamic and brake cooling function; the differences are material, weight, and price.
Why does installation require drilling holes in the factory bumper? The brake cooling ducts need to connect through the bumper to direct airflow to the front brakes effectively. Two holes are drilled into the rear face of the factory front bumper to create that connection point. This is a permanent modification to the bumper, which is why Top Secret specifies sheet metal factory installation rather than a general workshop environment. Factor this into the decision if returning the car to stock is a future consideration.

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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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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