The Nissan VQ35DE and VQ35HR in the 350z are both great engines. They deliver great NA performance, power, and sounds. VQ35 engines are also easy to upgrade and mod for more power. Among one the best upgrades include a set of Nissan 350Z headers. It's a great power mod that also comes with plenty of other benefits. In this guide, we discuss the best 350z headers along with benefits, hp gains, cost, and more.

This guide applies to all Z33 350z models with VQ35DE and HR engines. Be sure to double-check the accessories, though. Some titles are only suitable for DE engines, while others may only be suitable for HR. Many 350z headers will fit both engines. We could also call the 350Z the Z33.

What Are 350z Headers?

The headers simply refer to the engine's exhaust manifold. The word header is usually only used to describe aftermarket or upgraded exhaust manifolds. Anyway, the exhaust manifold is bolted directly to the exhaust port of the engine. This is the first part of the bolt-on exhaust system.

Exhaust manifolds or headers just help the exhaust gas flow out of the engine, through the cat, and eventually out the tailpipes. Because of its location, it is often the most important part of the exhaust.

On the surface, a header or exhaust manifold is actually what it is. They are a simple part of the exhaust but play a very important role. In the next section, we'll dive into long tube headers, advantages, power gains, and more. After that, we've listed some of the best Nissan 350z headers.

Nissan Z33 Long-tube Headers

You may come across two main types of headers - shorty or long-tube. The long tube header design simply has longer individual tubes (as shown at the beginning of the article) before merging into a common collector. 350z long tube headers promote faster exhaust flow and better scavenging. Therefore, they also reduce exhaust gas reversion.

The 350z long tube fitting is the best choice for performance. They will minimize backpressure and exhaust reversion. If power is the end goal, then long fittings are the way to go. The only downside is that they are more challenging to install and may require an O2 sensor extension harness.

Benefits of 350z Header Upgrades

Let's discuss some of the benefits of the Nissan 350z header. Of course, many people are in the market for headers because of the power gain. That's not the only benefit of aftermarket headers, though. Several benefits of the 350Z fitting upgrade include:

  • 5-20 horsepower
  • 5-15 torque
  • Reduce back-pressure
  • Lower EGT's
  • Improved exhaust sounds

A set of 350z headers can provide a horsepower gain of around 5-20 hp and 5-15 torque. We'll return to the topic of power gain later. There's a lot to discuss when it comes to the many other benefits of header upgrades.

Reducing backpressure is one of the main goals of the header. The factory 350z exhaust manifold is perfect for emissions and their intended use. However, they create a lot of backpressures that can hurt performance and overall engine health.

This is because back pressure slows exhaust flow and traps heat in and around the engine. Again, it increases exhaust recirculation, which is the process by which exhaust gas returns to the combustion chamber. The header increases exhaust flow and reduces exhaust temperature.

Finally, you'll notice a louder, more aggressive exhaust note with a set of headers. With other stock exhausts, the sound is usually not overly intrusive. It's usually louder on cold starts or with the heavy throttle. Be careful if you plan to modify any other part of the exhaust, as things can get too loud very quickly.

Nissan 350Z Headers HP Gains

Alright. We quickly touched on the rough 350z header horsepower gains above. We'll expand a little here, but it's always hard to provide power gains. It can vary based on many factors such as different dynamometers, other modules, adjustments, conditions, etc. 10-20 hp and 5-15 torque is a good rough estimate of the 350z header horsepower gain.

Some people may see more power, while others see less. There are a few major things to consider, though. Long fittings with cat removal will provide the most benefit. With proper tuning to account for header upgrades, you may see gains at the high end. Those sticking with high traffic or OEM cats and short heads should expect a low end.

Regardless, the 350z exhaust manifold upgrade is still the best option for your buck conversion. Without serious mods like boredom, stroking, or forced induction, it's hard to find a better power mod than a set of titles. This is a simple add-on module that delivers impressive results.

Catless vs High-Flow Cats

This topic is related to the discussion of long tubes vs. short heads. Long tube headers will remove your catalytic converter. Without cats, your car won't pass emissions tests or inspections. Street use is also illegal. Shorty headers leave the OEM cat tubes in place so your emissions are still legal.

However, with the restrictive stock cat in place, you don't get the full benefits of the 350z header upgrade. You can delete them all or choose a high-traffic cat upgrade. This provides a good middle ground for performance and potentially keeps emissions legal.