Nitrous Oxide Plate

What Is a Nitrous Oxide Plate?

A nitrous oxide plate is one of the most popular and straightforward methods for delivering nitrous oxide into a performance engine. Nitrous oxide plates are machined spacers that mount between the carburetor or throttle body and the intake manifold, spraying a precisely metered mixture of nitrous oxide — and in wet-system configurations, supplemental fuel — directly into the incoming air charge. The result is a denser, oxygen-rich mixture that allows the engine to burn more fuel per cycle and produce significantly more power on demand.

Unlike single nozzle or direct port injection methods, the plate system creates a relatively even distribution of nitrous and fuel across the entire intake opening. As one technical resource explains, a plate system is mounted between the intake manifold and the throttle body, creating a more even distribution than a simple nozzle setup. This makes plate systems a favorite for both street enthusiasts and serious drag racers who want broad, consistent power delivery without invasive modifications to the intake manifold itself.

How Nitrous Oxide Plate Systems Work

When nitrous oxide (N₂O) is heated in the combustion chamber, its molecules decompose into nitrogen and oxygen. This releases a higher concentration of oxygen than normal air provides — enabling the engine to consume more fuel and generate more power with each combustion event. The nitrous plate facilitates this process by atomizing the nitrous (and fuel, in wet systems) through internal spray bars or perimeter injection ports machined directly into the plate, ensuring the charge is evenly distributed before it enters the intake runners.

Plate systems are available in two primary configurations. Wet systems inject both nitrous and supplemental fuel through the plate, providing complete fueling control independent of the engine's existing fuel system. Dry systems inject only nitrous oxide, relying on the engine's ECU to add the extra fuel through the injectors. The wet plate approach is the more traditional and widely used setup, particularly on carbureted engines, and is generally preferred when chasing larger power numbers.

What to Consider When Shopping for a Nitrous Oxide Plate

• Carburetor or throttle body flange size: Plates are designed for specific bolt patterns (e.g., 4150, 4500 square-bore, or OEM EFI throttle body sizes like 78mm, 90mm, 102mm). Match the plate to your exact intake configuration.
• Wet vs. dry operation: Determine whether you need supplemental fuel delivery through the plate, or if your engine management system can handle fueling independently.
• Horsepower range: Jet sizing determines the power level. Most systems are adjustable across a wide range — from modest 50 hp bumps to 400+ hp shots — by swapping jets.
• Material and construction: CNC-machined billet aluminum plates offer superior atomization, precise distribution, and long-term durability compared to older cast designs.
• Supporting modifications: Larger power levels require a capable fuel pump, fuel pressure safety switch, and an engine bottom end that can handle the added cylinder pressure.

Top Nitrous Oxide Plate Brands

NOS (Nitrous Oxide Systems) is the brand that essentially defined the category. Born in the late 1970s when two racers perfected nitrous oxide delivery for automotive use, NOS quickly built a reputation for easy-to-install kits engineered from high-quality materials. The brand aided both the first 200 mph and the first 6-second passes in drag racing's Pro Mod class, cementing its legendary status on the strip. Today, NOS plate kits span a wide range of carbureted and EFI applications.

Nitrous Express (NX) has been pushing plate technology forward since 1996, drawing on deep experience in flow-bench development and precision CNC machining. NX pioneered billet nitrous plates and has continued to innovate with their Assassin and Spraybarless plate designs, which eliminate traditional spray bars in favor of perimeter injection patterns that deliver superior atomization and cylinder-to-cylinder distribution. Their application-specific plate kits cover everything from classic carbureted V8s to modern EFI platforms like the GM LS, Ford Coyote, and Dodge HEMI.

Speedmaster rounds out the lineup with value-focused nitrous plate options that give budget-conscious builders access to the performance benefits of a plate-style system without compromise on basic quality and fitment.

Wilson Manifolds brings its deep roots in intake manifold engineering to the nitrous plate category, offering products well-regarded in racing circles for their attention to airflow dynamics and precision manufacturing — a natural extension of their manifold expertise.