350z Intake Install Guide

Have an install guide you'd like to share or even unformatted pictures? Contact the editor.

by Sanjeev Verma
struan87@yahoo.com

Description
This is a relatively simple improvement that provides one of the most cost-effective upgrades to your G35. The stock Infiniti intake tube has two resonators, whereas the Nissan tube has none. This was most likely designed to reduce noise, but it also drops engine output by approximately 5 hp. After installing the 350Z tube, you will have slightly higher power and a more aggressive engine note at high RPMs.
Since this installation is fairly easy, it is a good first project if you are unfamiliar with your engine.

Cost
The easiest way to obtain a 350Z intake tube is from a 350Z. If you know someone who is replacing their intake, they will probably sell you their stock tube. You can also check with your local Z car club or search web sites such as ebay. I bought my tube for $40 from a 350Z owner who had just installed a ProCharger.

The 350Z intake tube:

Tools Required

• 10mm socket wrench
• Flathead screwdriver
• Philips screwdriver
• Pliers

Precautions
These should go without saying, but:

• Turn your car off! There is absolutely no reason to open a running engine.
• Wait for the engine to cool completely before you begin work. The intake (like any other engine part) can get very hot.
• Before you remove anything, line up your new intake tube with the old one so you can be sure it will fit

  

Step 1: Remove the engine cover
Using the 10mm socket wrench, remove the four bolts shown below. You will then be able to lift off the entire plastic engine cover to expose the intake tube and plenum.

Step 2: Disconnect and remove the stock tube
Using the 10mm socket wrench or an appropriate screwdriver, loosen or remove the three screws that are holding the stock tube in place. These screws are marked in red on the picture below. The screws on each end of the tube need to be loosened enough that the bands allow the tube to slide easily.

Next remove the emissions hose (marked in green) by squeezing the clamp with a pair of pliers. When the clamp is compressed, the hose should slide off easily.

Once the stock tube is no longer held in place, you will need to gradually work it out of its position. One of the resonators sticks down into the engine area a few inches, so you will have to be careful not to force it too much or it could damage internal parts. I found that the easiest way was to compress the pleats on the lower end of the tube and slide that end off the air filter box (shown below in green). Then the tube can be lifted out with a medium amount of force. Be very careful not to damage the airflow sensor (shown below in red)! You should not need to apply any force in that area.

Once the stock tube is removed, you can discard it (or keep it around…you never know when it might come in handy). You should have removed three parts—the pleated rubber section, the plastic resonator box, and the rubber upper tube—that are all connected together. Your engine should now look like the bottom picture; all the points of connection are highlighted.

Step 3: Install the new tube
Now you are ready to install the 350Z tube. You will notice that the emissions hose attaches on the underside of this tube, unlike the stock tube. Therefore, the first thing you need to do is attach the emissions hose. The easiest way to do this is to squeeze the clamp with pliers, then slide it an inch or two up the hose. It will now be very easy to slide the end of the hose over the port on the 350Z tube, then squeeze the clamp and slide it back to its previous position. There will probably be an indentation in the hose to show you where the clamp was before.

Next you will put the 350Z tube itself into place; this is most easily done by following the removal steps in reverse. First, put the rigid end of the tube around the throttle actuator port (shown at the top of the figure below), then compress the pleated rubber end and slide it over the air filter box port. The two ends of the tube should fit snugly on the ports, and the mounting bracket should line up with the screw hole on the engine block. Ensure that the tube is stretched to its longest length; if the accordion pleats are compressed too far, the tube will not be tight enough on the two ports. Next, guide the metal bands at each end to the correct place and tighten them by hand. There is no need to make them overly tight. Then replace the screw on the mounting bracket, and your tube should look like this:

Step 4: Replace the engine cover
Place the plastic cover on top of the engine, making sure to line up the bolt holes. The cover should fit exactly as before; if there seem to be any obstructions, double-check to make sure the tube is installed correctly. Once the cover is installed, replace the four bolts using the 10mm socket wrench.

That’s all there is to it! Start the car and enjoy your pleasant engine note and slight increase in power.

Have an install guide you'd like to share or even unformatted pictures? Send it to editor@6mt.net.