Modified stock intake -- a new variation on an old theme

[dr-rjp]

After reading a lot of posts by people who have played around with their stock setups, such as hacking their airboxes, and adding hoses to where the resonator would go, I decided to experiment with mine.

Speaking of Maxima.org, there are a few people on there who feel like I am personally offending them by having the audacity to modify my stock intake. I cannot tell you how many times I heard someone say, "It's all been done before," and "You're wasting your time," and "What makes you think that you're smarter than Nissan engineers?"

My oh my. Galileo never had it this tough.

Anyway...none of their detractors would dissuade me because (1) I was not trying to reinvent the wheel, and (2) experimenting is fun and one cannot put a price on self-discovery.

Before I set out to do my mods, I decided to do some objective testing on airflow and air temperature using an anemometer to see what, if any, changes the m ods would produce. I set up an experiment to record both the air velocity and air temperature inside the air box.

Now, here is how I modifed my stock intake:

The first thing that I did was to cut off the lip on the bottom where the eblow to the resonator goes. I cut it even with the intake.

Next, I cut a hole in the top and bottom of the scoop to remove the center divider so that more air could enter it. This center divider is shaped like an hour-glass. The bottom of the hood is shaped to match it, such that the scoop is divided off into two sections (but the sections are not equal in width nor the space through which air is allowed to enter. I guess that Nissan engineers thought that the hood needed to be supported in the middle of the air scoop -- not exactly a good idea, IMHO).

These holes were then sealed over to provide one, single, unblocked airway (well, sort of).

As another touch -- and this step is a one-of-a-kind mod --- I coated the entire intake with liquid ceramic. Liquid ceramic is a roof coating designed to insulate the inside of a house from outside heat. When homes have roofs coated with this stuff, the air inside is up to 30 degrees cooler! The idea behind this step was to keep the incoming air as cool as possible.

Now, as a final touch -- and this is another Dr-RJP original -- I added what I call, a "scoop extender."

The way this works is that air hits the extender and is deflected up and into the scoop. The nice thing about it when it rais is that when water hits it, the water spalshes off to the sides and never enters into the scoop.

Here are some photos (taken before I coated it).

Photo #1 is a side view of the intake.

Photo #2 was taken facing the scoop to show the new opening.

Photo #3 is of the "Scoop extender."

[Beancooker]

So what were/are the results of your testing? If testing is still going on, post up when you get results. Ya got me curious!

[dr-rjp]

I am still trying to find a place where I can insert the anemometer without compromising air flow or the seals around the intake and air box.

The anemometer I have is rather large: it is about the width of an iPod Nano, and about three Nano's thick. The top of it has a lttle fan that spins whenever air hits it.

What I tried first is laying it on the top, and in the middle, of the air filter.

One thing I noticed right off the bat is that the air flow is incredibly uneven across the face of the air filter. You probably have noticed this as well when taking out a used air filter after several thousand miles of use: the side of the filter closest to the intake is dirty, while the other side is relatively clean.

It makes sense since the side closest to the intake would draw in more air than the other side.

But, there is also the factor of the airbox itself -- whereby the intake side has the most interior volume, and the opposite side has the least interior volume (thanks to the inside being narrowed to fit over the wheel well).

I may put the anemometer inside the accordian-shaped rubber tube connecting the throttle to the MAF. I have a spare tube that I can cut a rectangular hole into to hold the anemometer. This setup would allow me to take readings without interfering with the Mass Air Flow sensor.

I'll keep you posted.

[Beancooker]

Might consider this:

http://www.cosmoracing.com/pro...d=979

http://www.cosmoracing.com/pro...=1367

[dr-rjp]

Might consider this:

http://www.cosmoracing.com/pro...d=979

http://www.cosmoracing.com/pro...=1367

I might...if I wanted to buy one (although I cannot see where they could fit a full length CAI between the wheel well and the bumper -- there is no space. uness they cut into the under car cover).

This is a fun experiment for me. Not trying to reinvent the wheel or cheap out on buying a CAI.

[dr-rjp]

Here's the latest modification to my stock box. I call it White Thunder.

Yeah...I know. Lame name. BUT...it's the only intake around that is coated with liquid ceramic. Liquid ceramic provides lots of insulation for the box. I have not measured how cool it will keep the air since it has been raining here. When it stops, i'll install it, test it out, and lt you know how it did.
Modified by dr-rjp at 10:05 PM 11/7/2006

[Beancooker]

Liquid ceramic??? where can you purchace this? What's the brand name? Is it paint, or actual ceramic coating?

[dr-rjp]

It is

Liquid ceramic??? where can you purchace this? What's the brand name? Is it paint, or actual ceramic coating?

It is called Thermo-Shield, and you can buy it directly from the manufacturer of the same name. Here is the link to their website:

http://www.thermoshield.com/products_page.html

What I used is called Roof-Coat, and here is the official description:

Thermo-Shield® Roof Coats are highly efficient, energy-saving, flexible coatings, made from a water-based pure acrylic resin system filled with vacuumed sodium borosilicate ceramic micro spheres of less than 100 microns in size. Each micro sphere acts as a sealed cell and the entire mastic acts as a thermally efficient blanket covering the entire structure. These coatings are non-toxic, friendly to the environment, and form a monolithic (seamless) membrane that bridges hairline cracks. They are completely washable and resist many harsh chemicals.

BTW, they will send you a small trial can of it -- which is what I did -- and there is enough inside to put three coats on an intake.

[dr-rjp]

I got to try out my intake yesterday, and I really like the results. Unfortunately, I do not have any way of quantifying the increases I am getting, though, except for maybe doing a couple of hand-timed, acceleration runs. The local dyno shop does not do any "Dyno Days," and I don't care to shell out $100 just to satisify my curiosity. There aren't any local drag strips here.

All I can say is that it feels good.

[maxhopper]

What is the difference in weight of the snorkel/filter housing, with the coating .vs stock?

[dr-rjp]

What is the difference in weight of the snorkel/filter housing, with the coating .vs stock?

The coating is so thin that the weight difference amounts to a few ounces. Think of it as an extra layer of skin.

BTW, the primer adds a few ounces, too. Although a primer isn't necessary, it is highly recommended since the intake is made of a slippery plastic.

See attached file.