Plenum Spacer Installation

From Zwiki

Tutorial by: HyperSprite (member of 350z-tech.com)

This tutorial covers a Motordyne Engineering 1/4" Plenum Spacer install in the 350Z. The spacer arrived in the mail properly packaged to avoid damage. Pulling it out and laying it out on the bench shows they have done there homework on the kit, everything you need is in there.

In the Box

The 1/4" Spacer Top gasket (stock gasket cut special to fit) 6 1/4" mini spacers for the 6 internal standoffs, they have gaskets bonded to them. Bolts to replace the now too short stock bolts on the plenum and strut bar. 8 strut bar spacers. Full installation should take about one hour at a relaxed pace. Read through all of the instructions before starting.

Taking things apart

Remove the strut bar

• Loosen the two jam nuts on the left hand side.
• Mark the center and loosen it one full turn.
• Remove the 6x14mm head bolts and 2x14mm head nuts.
• Use a screw driver on the lock of the slide on wire connector and slide off.
• Use needle nose pliers to squeeze the snap in wire connectors and push them out.
• Carefully lift bar out of the way and set aside.

Remove engine cover

• Remove the 2x10mm head nuts and 2x10mm head bolts.
• Carefully lift cover and set aside.

Disconnect the "Z tube" from the throttle body.

• Loosen the clamp and pull back carefully.

Disconnect the vacuum line on the battery side of plenum

• Use pliers to squeeze the clamp a move it two inches toward the battery.
• Slide hose off of nipple.

Take off oil filler spill guard

• Remove oil cap
• Pull off spill guard (to avoid getting it clamped up in you plenum)
• Replace oil cap

Loosen and remove all plenum bolts

• Remove all 16x10mm head bolts and 2x10mm head nuts in opposite of tightening direction (see picture further down)

Spacer Install

Caution: Care should be taken not to drop anything into the intake manifold.

• Clean the plenum top and around it's edges to remove any dirt or debris.
• Lay the spacer on top of the plenum to find the correct orientation, lay the gasket on top of that, the twin arrows should be resting just above the matching ones already on the car.
• Lift the plenum and clean the riser post with alcohol or brake cleaner applied to a rag.
• Lift the plenum enough to get spacer and gasket in place and make sure the gasket is still lined up
• Using the new long bolts and medium bolts as a guide, put on the 6 riser spacers.
• Take out the two studs in the lower spacer.
• Replace upper plenum, make sure the gasket and spacers all stay in place.
• Tighten all the bolts in forward order to 61 inch lbs. (see picture below)
• Installed the rest in reverse order of disassembly, remembering to add the strut spacers for the strut bar.

This is a picture of the 1/4" spacer installed, there are no hood or strut bar clearance issues so even an informed inspector may not notice.