Plenum Spacers
From Nissan 350Z & 370Z Wiki
You will definitely feel this one. The stock plenum slopes down towards the front of the engine. Nissan designed this in order to clear the stock strut bar and hood on the 350Z (function after form). This sloping design restricts the airflow to the front cylinders, but an aftermarket plenum can help the front cylinders breathe. Aftermarket plenum spacers either increase the overall height or remove the downward slope in the design, allowing more volume and greater airflow to all cylinders. Higher airflow is needed to achieve more power.
- Note: Some plenum spacers will cause you to loose the stock strut bar.
Contents |
Angled Spacers
AAM Angled Spacer
- List Price: $349.00
- Found For: $269.00
- Design: angled spacer insert between upper and lower plenums
- Material: aluminum
- Application: N/A, F/I
- Notes: Improves air flow to all cylinders, spacers for strut bar fitment
- Altered Atmosphere
Flat Spacers
PURE
- List Price: 229
- Found For: $229
- Design: 10mm thick, waterjet cut from single aluminum plate
- Material: aluminum
- Application: N/A, F/I
- Notes: Improves air flow to all cylinders, includes strut bar spacers for use with OEM strut tower bar (others may fit)
- Pure
Esprit
- List Price: ----
- Found For: $490
- Design: spacer insert between upper and lower plenums (???mm)
- Material: ????
- Application: N/A, F/I
- Notes: Improves air flow to all cylinders, JDM
- Esprit
Skunk2 Composite Spacer
- List Price: $329.00
- Found For: $189.00
- Design: 5/8†(15.9mm) uniform thickness.
- Material: carbon composite
- Application: N/A, F/I
- Notes: Improves air flow to all cylinders, OEM style strut bars will not fit
- Skunk2
- Plenum Spacer Installation (Skunk2 )
Throttle Body Spacers
AAM Throttle Body Spacer
- List Price: $99.00
- Found For: $98.00
- Material: Aluminum
- Application: N/A, F/I
- Notes: Very effective when it comes to installing vaccuum lines for stuff like MAP sensors and boost controllers.
Reviews Etc
Insulation Test
Here is a report on the effectiveness of insulating the plenum in Texas. I installed my Motordynamics 5/16" spacer and isothermal kit (with valve) last month. I installed the kit with the valve turned off - no flow of coolant to the TB. I have been very pleased and impressed with the performance enhancement this mod gives - how much is due to the spacer and how much is due to the thermal insulation, I can't say. Unfortunately, I did not take the following temperature readings prior to the install so the results below are of less value than they might have been - but they are enlightening and introduce some fact into a subject with a lot of opinion.
I drove to work today taking a 20 minute route, mostly 60-75 mph with five minutes of stop and go traffic. The ambient temperature was 41 degrees F, and I noticed no issues with TB icing, etc. When I arrived at work I opened the hood and using a infrared thermal gun I took temperature readings aroud the engine compartment. Here is what I found:
Cam covers on front of engine = 143F Engine bay wall just behind the passenger side strut tower (by the shiney ID plate) = 119F Top center of plenum = 66F
It seems obvious to me that the plenum is cooler than it would be without the isothermal kit installed. Connected directly to the engine, I believe it should have been at least the temperature of the engine bay wall, perhaps nearly as hot as the cam covers, if the iso kit was not working. Yet the plenum was substantially cooler. This mod is no joke.
This test demonstrates several things. First, reducing the heat flow into the plenum (coolant and conduction from block) reduces the temperature of the plenum. Second, the incoming air absorbs heat from the plenum as it passes through (otherwise the plenum should have been closer to the temperature of the bay wall). This infers that by reducing the temperature of the plenum, the temperature of the incoming air is reduced, resulting in an unknown magnitude of performance increase from 1) an increase in the mass of air (rule of thumb - a 10 degree reduction equals ~1% hp) and 2) a reduction in timing retard caused by hot intake air. Added to the reduction in the plenum airflow restriction by running a spacer, and the total performance enhancement is quite noticeable.
Categories: Altered Atmosphere | Pure | Esprit | Skunk2 | Parts | Intake