On saturday, Maxpower and I installed our new Motordyne Plenum Spacer Iso Thermal gasket and Coolant Control Valves. It was a good thing we decided to do it togeather, as it was more difficult than we expected. The instructions pretty much glossed over the "gory details" that we encountered. We started on my 2003 G35 Sedan at 9:00 am Saturday morning and finished it at 12:30! We learned so much during my install that we were able to do Tom's (Maxpower) 2005 G35 Coupe in a little more than one and one half hours. The following are some pictures of this dual install. Enjoy and learn

 

We had both previously bought and installed the Motordyne 3/8 " spacers. The first pic is of the Iso Thermal gasket upgrade along with the Coolant Control Valve. The next 4 pics are of my 2003 G35 Sedan's plenum before removal.

 

Removal of the upper Plenum required all the hoses around the throttle body to be disconnected. This was a real pain in the a** and does require two people to do it.
The fifth picture shows two bolts that were required to be removed before the lower plenum could be taken off. These two bolts were not mentioned in the Motordyne install guide. The fourth picture shows the plenum spacer and the two gaskets removed, sitting on the workbench.

 

Now let's get the lower plenum off! Wait! The instructions don't say anything about all the other bolts that need removal....
#1)Another pic of the two extra bolts needing removal from the left rear of the lower plenum. #2) The bracket that has the 3 stamped on it needed removal as well.
#3) Showing the three bolts at the front bracket that also needed removal. #4) shows the rear lower plenum bolt removed #5) the front lower plenum bolt removed.
These bolts are in addition to the six bolts within the lower plenum that attach it to the intake manifold.

 

Remove the lower plenum and expose the intake manifold! Pic #1) intake manifold. Notice that the second intake appears to be completely clean while the others are discolored. This worries me! Pic #2) looking downward into the intakes. Pic #3) the lower plenum as it sits on my garage floor. Pic #4) the bottom of the lower plenum that makes contact with the intake manifild gasket. Pic #5) another view of that beautiful intake! Also notice in pic #1 how the right hand side near the oil filler appears to be oiled up. I never spilled oil when I changed my own oil...I bet the Stealership spilled oil all over the engine when they did their oil changes.... Lousy gorillas! I took Mineral Spirits and cleaned it up in pic #5.

 

Oil up the Iso Thermal gasket and place it on the manifold. Then reverse the process. Man...my back was aching after all the leaning over the engine.
Pic #1 is my 2003 Sedan getting put togeather. Pic #2 is the 2005 Coupe lower plenum exposed. Pic #3 is the new Coupe again. It is a 2005 with a little more than 4000 miles on her. Quite a bit cleaner than my 69,000 mile 2003 Sedan! Pic #4 &5 are the Coupes intake manifold. Notice how clean the intakes appear.

 

Put everything togeather and enjoy the good work! I had bought a Sears inch pound torque wrench for the initial plenum spacer install. It really came in handy! My magnetic pick up tool also came in handy for the bolt I dropped in Tom's engine. I actually dropped one bolt and one plastic plenum post spacer down my engine, forcing me to remove the lower engine cover to retrieve them. Man..that really sucks when you have to break stride to fix your own Fu*k up....

 

Here is a nice gathering of Nissan products, Tom's 2005 G35 Coupe, my 2003 G35 Sedan and my wife's 2000 Maxima. After we finished the install, I broke all my rules and cracked open the beer before 2:00 pm...hehe We took a spirited drive around the business park to check out the work. After about 5 miles of driving, we pulled over and popped the hoods. HOLY ****!! The plenums were just slightly warm, this mod has made a huge difference. I tried to touch my plenum after about 1 hour after shutting her down the other day and it was too hot to touch. So this mod MUST result in cooler air entering the intakes.....more HP.

 

cato,

Thank you for all of your efforts. Your post is quite detailed and informative. I am quite sure that your information will be extremely beneficial to me with regard to my future mods, as with others.

Congrats to you on your own mod. I trust everything is working up to your expectations.

 

thanks cato and maxpower!.........i have the mod sitting here in my home office and didnt get time this weekend to install.........i will get to it next weekend and im sure your DIY will help me tremendously. Thanks!

 

Congrats on your latest mod. Your installation posts and pictures should help others who haven't done it yet. I've done this installation about a dozen times and now have a one hour par time... depending on the number of Coronas consumed.

We tested the Iso Thermal upgrade over last summer and found it dropped the upper plenum temps as much as >80F on a 105F day.

Did you buy an in-lb rather than a ft-lb torque wench? The lowest setting on my Craftsman ft-lb torque wrench is 20, twice the maximum factory value (9 - 10 ft-lbs or 108 - 120 in-lbs) for the lower and upper collector bolts and nuts.

 

DaveO,

Yeah, I bought the Sears inch pound torque wrench. My mistake in the above post. (I've corrected it now..thanks!) It really came in handy. As you know, I had planned on installing new spark plugs during this install... But we took so long to get to the intake gasket, and the plenum was actually in the way, and I was so discouraged, and my back was aching so much... Well..you get the picture! At that point I thought it was actually better to pay somebody to install the spark plugs. Maybe some other day

 

"I've done this installation about a dozen times and now have a one hour par time"

DaveO,
had there been a third install to do that day it would have been less than one hour, we took our time on the first (cato's) to get it right and were moving at a good clip on mine with the experience we gained. we followed Tony's recommendation and tightened all the bolts in the progressive sequence of 30-60-110 inch-lbs.

Thanks again Cato

max

 

Why is it necessary to have two people for removal of all the plenum hoses? I haven't looked at mine yet, but I was planning on doing this upgrade this weekend.

 

Well...... You might be able to do it alone. But I was glad I had someone to hold the upper plenum while the other disconnected the hoses. The two hoses that are relly tough to remove are situated at the bottom of the throttle body, with hose clamps face in a particulary nasty direction. It requires that somebody hold the upper plenum while the other squezes in to remove the hoses. You will need pliers to get the hose clamps off the hose. Good luck if you are planning on doing this yourself. I think you will regret it.