I have always wondered what the purpose is of the capped vacuum port on the front left side of the upper intake plenum. Nissan certainly would not have taken the time to add it if it is not going to be used. Anyone have any idea what purpose it serves?

(It is under the engine cover if you still have your cover on.)

 

I wondered the same thing last night when I switched out my stock for the Crawford. I was like....what tha??

 

was that easy? i'm getting my crawford late this week or early next week.

 

It was a piece of cake! Just make sure you follow Vandy Z's instruction manual. Lots of nuts/screws that can be misplaced if not careful.

 

Pretty straight forward for my coupe. I am pretty clueless when it comes to engines, but the instructions were very simple. There were a couple of small areas to work on when removing the plenum, but nothing too tight.

I broke my wrist last December. I thought it was pretty much healed but I had a couple of f-bombs when I was l removing the electric throttle control actuator with an allen wrench. Those babies are on tight.

There is a great post over at freshalloy.com in the g35 forum on the install. It is called "Complete Idiot's Guide to Crawford Plenum Install" It has a link to a guide that a forum member put together that has pictures of the process that helped me. It was for the G35, but they are very similar.


G35 Crawford install details

 

Yah now that you bring it up I wonder why its plugged. The most educated guess is that since this engine is used in many other nissan cars, that they use it to vacuum somewhere.

Could be an overseas thing they use as well. If anyone knows the answer please let me know!

 

We use it on the dyno to watch boost on a portable boost guage... just plug it on and go!

 

I think it's got something to do with JDM spec engines. They probably had extra stuff installed for their emmissions standards.

When my dad bought a JDM VG30DETT for his car, it had some extra stuff installed on the intake plenum. All of it was removed prior to engine installation.

 

I would think that this port could be a potential problem. Let's say you were to boost the engine but you never removed the plenum cover therefore you did not know about this port. Eventually, if not immediately, this cap is going to pop off under boost because it is not mechanically secured to the port....

 

Good point, maybe I'll put a hose clamp on mine.

 

I wouldn't worry about it...

As small as it is... it isn't going to create an issue. For all the guys boosting 7lbs+ ... no probs!

 

Well, it only takes 30 seconds since my plenum cover is not installed, so I'm gonna go ahead and do it anyways.