Peak Performance - Choosing The Best Nissan 350Z Plenum Spacers

The Nissan 350Z, a renowned Japanese sports car, has captured the admiration of gearheads across the world with its dynamic design, remarkable handling, and potent VQ35 V6 engine. But as with all sports cars, some Z owners want more than what’s offered from the factory, and thats where performance modifications like an aftermarket plenum spacer for your VQ35DE come in!

The Importance of Plenum Spacers for Your VQ35DE

If you looking to increase the performance of the 2003-2006 Nissan 350Z, plenum spacers have a crucial role to play in both N/A and boosted builds. Developed to increase the plenum volume and adjust air distribution across all cylinders, the plenum spacer is a great way to help your VQ35DE catch up to later VQ35HR power Z33s that received a major overhaul towards the end of the production run. Plenum spacers for the VQ35DE not only increase horsepower, torque, and overall performance, they are one of the most budget-friendly modifications that every 1st gen 350Z owner that’s looking for more horsepower should install right along with an intake, exhaust, and a tune.

Reviewing The Best Nissan 350Z Plenum Spacers

In the pursuit of improving your Nissan 350Z's performance, not just any plenum spacer will suffice. In the section below we'll examine five of the finest Nissan 350Z plenum spacers available on the market today. All of these plenum spacers have a proven track record so you can rest assured knowing you're buying a quality part for your Fairlady Z.

BLOX Racing Gen2 HyperTemp Plenum Spacer

BLOX Racing 2003-2005 Nissan 350Z / Infiniti G35 - 5/16 Thermal Shield
BLOX Racing Gen2 HyperTemp Plenum Spacer

Constructed from a cutting-edge, high-temperature polymer, the BLOX Racing GEN2 HyperTemp Plenum Spacer is one of the best plenum spacers you can purchase today. Reducing heat transfer from the engine to the intake manifold ensures your Nissan 350Z's performance remains uninterrupted even during extreme engine temperatures. The BLOX Racing Plenum Spacer features a high temp polymer construction, promising to improve your 350Z's performance with an easy 100% bolt-on installation process that comes with all necessary hardware. This Blox plenum spacer stands the test of big-boost turbo and supercharged engines, offering both longevity and an increase in performance at a wallet-friendly price.

Skunk2 Intake Plenum Spacer V2

Skunk2 Intake Plenum Spacer V2 Nissan 350Z/G35
Skunk2 Intake Plenum Spacer V2

The Skunk2 Intake Plenum Spacer V2, specifically designed for the Nissan/Infiniti VQ35DE, is a performance upgrade that promises to provide a notable increase in your Nissan 350Z's engine performance. Boasting a thicker design to increase plenum volume and lower intake temperatures, it improves airflow efficiency, resulting in a mid-range power surge that can be felt during your daily drive or at the track. 

Along with gains as high as 10hp and a fuel efficiency boost of over 2mpg, this aerospace thermo-polymer composite intake plenum from Skunk2 provides unmatched thermal insulation capabilities. Its unique design eliminates the need for an OEM gasket, offering an injected sealed perimeter for the perfect fit. Complete with all the required hardware, Skunk2 guarantees an easy installation process for any DIY 350Z owner.

GKTech Plenum Spacer

GKTech Plenum Spacer

Designed with an eye on quality, the GKTech Plenum Spacer is a great performance upgrade for your Nissan 350Z's engine. Its thicker profile increases air inflow to the front cylinders, boosting mid-range torque, top-end power, and fuel efficiency. This intake plenum spacer not only increases your VQ35DE's horsepower by up to 10hp but also improves throttle response. What sets this 350Z plenum spacer apart is its easy installation and the included hardware and gaskets, addressing common manifold issues in one fell swoop. 

Crafted from premium, lightweight aluminum, this spacer elevates the plenum by 5/16” to 1/2”, clearing the OEM strut bar and engine cover with ease. All these features come together to provide a hassle-free performance boost to your Nissan 350Z, something that GKTech is proud to offer!

AAM Competition Angled Intake Plenum Spacer

AAM Competition Angled Plenum Spacer 03-06 350Z-G35
AAM Competition Angled Intake Plenum Spacer

The AAM Competition Angled Plenum Spacer, tailored for the Nissan 350Z, Infiniti G35 & Infiniti FX35 with the VQ35DE engine, offers a perfect blend of improved performance, value, and superior build quality. The unique angled design improves airflow and expands the intake plenum’s overall volume, unlocking upper RPM range power and delivering consistent horsepower gains. Made from billet aluminum, this spacer fits between the factory upper and lower plenum, helping to increase airflow into your VQ35DE’s cylinder heads. The installation is straightforward, and the package from AAM includes spacers for the original strut bar, ensuring you won’t need to modify any parts to make things fit.

Z1 Motorsports Plenum Spacer

Z1 350Z / G35 VQ35DE Plenum Spacer

Crafted from top-tier, thermal-resistant material, the Z1 Motorsports Plenum Spacer is a game-changer for your 350Z - G35 VQ35DE. The angled aluminum design improves engine airflow and allows you to keep the factory strut tower brace. By raising the plenum, Z1’s plenum spacer ensures increased airflow to the front cylinders, leading to substantial gains in mid-range torque and top-end power. Not only does this plenum spacer deliver impressive power and torque improvements, but it also offers a consistent power delivery while minimizing heat soak. The Z1 Motorsports Plenum Spacer is a valuable addition to your 350Z, providing noticeable horsepower upgrades when paired with the right supporting modifications and tuning.

What Does A Plenum Spacer Do?

To get the most from your Nissan 350Z's engine, it's key to understand what a plenum spacer is and how it works. In essence, a plenum spacer is an aftermarket engine component that increases the plenum chamber volume in your engine, refining air distribution to each cylinder. Adding a plenum spacer is a budget-friendly modification for power-hungry Nissan 350Z owners that are looking to get the most out of their VQ35DE engines.

How Does a Plenum Spacer Work in the Nissan 350Z?

In a Nissan 350Z, the plenum spacer creates extra space between the throttle body and the plenum. This simple modification enlarges the plenum chamber's volume, promoting better air distribution to all cylinders. The result? A more efficient combustion process, leading to noticeable increases in horsepower and torque.

Performance Benefits of Nissan 350Z Plenum Spacers

Black Nissan 350Z Drifting on Track
"Smoky" by MIDWST.BLUR is licensed under CC BY 2.0

Increased Power and Torque

By installing a plenum spacer in your Nissan 350Z, you can expect a notable bump in power and torque, particularly in the mid-range. This improvement can radically transform your driving experience, making it more enjoy on the street or at the track..

Improved Throttle Response

Plenum spacers also improve throttle response, making your Nissan 350Z’s VQ35DE react more promptly and smoothly to your throttle inputs. This responsiveness improves your Z’s driving dynamics, making it even more enjoyable to drive. 

More Fuel Efficient

The optimized air distribution and combustion efficiency provided by a plenum spacer can also improve fuel efficiency. This benefit means you can enjoy the improved engine performance without frequently visiting the fuel pump if you manage to go easy on the throttle with your increased power!

Reduces Heat Soak

Premium plenum spacers, crafted from thermal-resistant materials, help mitigate heat soak, maintaining your engine at optimal operating temperatures. This benefit contributes to maintaining peak performance and extending engine life, especially for turbo or supercharged VQ35DEs.

How To Choose A Nissan 350Z Plenum Spacer

BLOX Racing Gen2 HyperTemp Plenum Spacer


When shopping for a plenum spacer, prioritize durability. Look for high-grade materials like premium polymer or aluminum, which can withstand high temperatures and pressures over time.

Size and Thickness

The size and thickness of the plenum spacer affect the increase in plenum volume. Choose the size and thickness that align with your Nissan 350Z's specifications and performance goals. We recommend a plenum spacer in the 5/16” variety with the larger sizes working better for forced induction builds.

How To Install Your Nissan 350Z Plenum Spacer

Tools Required

Typically, you’ll need a range of sockets, wrenches, and screwdrivers, along with a torque wrench, for the installation process.

Step-by-Step Instructions

Always adhere to the instruction manual that comes with the plenum spacer. This will guide you through the entire process and help avoid any mishaps. There are also a significant amount of walkthroughs online so don’t forget to open up a tab if you are unsure about the installation process.

Safety Measures During Installation

Always ensure that the engine is cool before you begin the process. Disconnect the battery, and always tighten all bolts according to the manufacturer's recommended torque settings to prevent any leaks or potential damage.

OverRev’s Nissan 350Z Plenum Spacer Guide

Slammed Burnt Orange Nissan 350Z
"Edit -1-29" by Dane is licensed under CC BY 2.0

We appreciate the time you’ve spent exploring the world of plenum spacers, a great investment for Nissan 350Z owners eager to improve their Z's performance. Each plenum spacer we've discussed carries its unique advantages, reinforcing the fact that your final choice should align with your specific needs, preferences, and budget. 

But wait! The journey to transforming your 350Z doesn't end here. We encourage you to delve into our comprehensive selection of 350Z-focused content, including our extensive tuning guide, exhaust guide, and intake guide along with a slew of other Nissan 350Z content. These resources offer an abundance of tips and tricks to assist you as you tailor your Nissan 350Z to your liking. Thanks again for reading, and enjoy your journey to perfecting your Fairlady Z!

Nissan 350Z Plenum Spacer FAQ

Are plenum spacers safe for my Nissan 350Z?

Absolutely! Plenum spacers are safe for your Nissan 350Z, provided they are correctly installed and are high-quality components.

Can a plenum spacer improve my Nissan 350Z's performance?

Definitely! A plenum spacer significantly improves your Nissan 350Z's performance by improving air distribution, which in turn improves horsepower, torque, and fuel efficiency.

What is the average cost of a quality plenum spacer for a Nissan 350Z?

The cost can range from $100 to $300, depending on the brand, material, and design. Always ensure you're choosing a high-quality plenum spacer to get the best value for your money.

Can I install a plenum spacer on my Nissan 350Z by myself?

Yes, with a basic knowledge of car repair and the right tools, you can install a plenum spacer on your Nissan 350Z by yourself. However, if you're unsure, it's best to get it installed by a professional.

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