Ralliart Custom Intake Project
 

I have been leaving off doing an intake for a long time now because I didn't want a CAI (too much water) and the SRI suffered from too great of heat soak. Coming from the BMW crowd where everyone builds custom air boxes for their SRI I thought I would be the first to try to design one for the Ralliart.

I always liked the filter placement for the AEM SRI but felt it was too expensive and that I could get the same results from chopping the MAF tube from the factory airbox. Many people have done this so nothing new here. I did buy an airbox from another member since I wanted to keep my own in case I went back to stock.

Here are the additional materials I bought.

AEM 2.5 in Dryflow filter.

24in X 24in sheet metal from Lowes $10.

Rubber Pipe Insulator $4

Some small screws with nuts $2.

Black high temp paint.

After removing the factory box I looked around to get ideas on the design and just began to work from there. I wanted to use the factory mounting holes and knew I would need at least two mounting points for the box to be rigid and not move. First I did a mock up with card board and made adjustments until I felt prepared to start cutting the metal.

[IMG]http://s218.photobucket.com/albums/cc306/yf_tai00/Air%20Filter
/?action=view&current=CIMG3978.jpg[/IMG]

http://i218.photobucket.com/albums/c...r/CIMG3976.jpg

http://i218.photobucket.com/albums/c...r/CIMG3977.jpg

Next lay out the cardboard template over the sheet metal and start cutting. This is done with a pair of tin snips. The sheet metal I bought was 26 guage and very easy to bend. For the bends I just went onto my back deck and bent the metal over the wood edge. The bends make the metal much more rigid. I also made a one inch lip at the top and bottom of the box to increase rigidity.

http://i218.photobucket.com/albums/c...r/CIMG3979.jpg

http://i218.photobucket.com/albums/c...r/CIMG3980.jpg

You will see that I had it built to enclose everything. THIS MAY BE THE BEST WAY ON OTHER CARS BUT NOT ON OURS.

Needless to say I painted and mounted this last night and took it for a spin. I have a Scanguage II in my car that gives me intake temp and it was shooting off the charts. I assume it must have been since I ran the filter tube through the metal and since the box was all one piece when it got hot it just trapped the heat. I also could not get the factory scoop to mount again as it was hitting the filter. I think BMW's and other cars can get away with the enclosed box because their filters mount right behind the headlights while ours is tucked too close to the engine.

So after sleeping it off I woke up this morning to design a new box. This box would still block heat but would not touch the MAF tube and allow me to use the factory scoop to route fresh air. Here are the pics of the finished new design.

http://i218.photobucket.com/albums/c...r/CIMG3985.jpg

http://i218.photobucket.com/albums/c...r/CIMG3984.jpg

http://i218.photobucket.com/albums/c...r/CIMG3986.jpg

Here are the two mounting points. One is the one AEM uses to mount the SRI tube. It is the bolt that holds down the coolant temp sensor bracket. Here is a pic.

http://i218.photobucket.com/albums/c...r/CIMG3987.jpg

The other mount is the factory airbox mount that is closest to the exhaust manifold. You will need to place a really fat washer of sorts ( I used a rubber piece that was about a 1/2 inch and drilled a hole) in order for the long screw to tighten all the way. Rubber is great and will help dampen vibration.

http://i218.photobucket.com/albums/c...r/CIMG3988.jpg

I used small screws and bolts here and there to increase rigidity. Finally I drilled a hole on one side and ran a zip tie through to hold the throttle cable. With everything bolted down I added the rubber pipe insulation to the spot where the factory snorkel will go and some along the top for looks. As you can see it fits like a charm and does not flex or move at all. For paint I used high temp stuff used to paint barbecues and it has a nice flat finish.

[IMG]http://i218.photobucket.com/albums/cc306/yf_tai00/Air%20Filter
/CIMG3989.jpg[/IMG]

Now for the final results.

I ran the car around the block to check for rattles etc. and there wasn't a squeak. The intake temp numbers showed much lower. I went for a longer drive where I could watch the numbers and the results were great. Compared to the stock box I would say on average my numbers are about 5 degrees cooler across the board. The great part is how fast it cools of once you start rolling. Temps drop right away. This is still not going to be quite as cool in stop and go traffic because the filter is still under the hood but by just doing hand test with the hood popped you can feel the difference in temperature around the filter . For me this is the best of both worlds and a good compromise between the two. I did run the car without the box and just the filter ( this would be comparable to AEM SRI) and the numbers were better that my first box, ( anything was) worse than stock at idle, and slightly higher than my final setup all around.

A CAI will still give the most overall cooler temps but I think this is definitely second. I will say that I think AEM has the best design on filter placement which is why I copied them. We really need to get our filter as far away from the engine as possible.

Hopefully some people found this interesting. I would be happy to share my design ideas with anyone that wants. And don't bash on the fact the filter is held up by zip ties. Mounting that is a future project and in the meantime zip ties really do work well.

this is different..... interesting, hmmm.

ive been contemplating cutting the maf tube off and building a box like this, but my only concern is with my carbon hood, and the 2 big vents and one little scoop letting in water in the rain and saturating my cone filter... any thought's/idea on running a SRI with a VIS carbon evo style hood??

The nice thing about sheet metal is you can build any box you want. I am not extremely familiar with the VIS hood but I assume you could build the box in a way that would keep the rain off the filter.

slc-ralliart can you make me one of these? i do belive i have your number in my inbox just pm me for price and stuff and i can pick it up whenever its finished if you do agree to build me one i also have the 04 ralliart

^ Yeah I should be able to make another fairly easy. Have you already chopped your factory air-box? You will need to do that and get a cone filter. It might take me a couple weeks since I just dropped off the metal cutters at my parents and need to get them again. I'll shoot you a pm and we can discuss it more.

I have an AEM SRI but I am still worried about heat soak.
Is there anyone selling custom-made heat sheilds? Or do I have make one myself?

I have an AEM SRI but I am still worried about heat soak.
Is there anyone selling custom-made heat sheilds? Or do I have make one myself?

No one sells them if im correct

Pretty cool build, and good luck with it. But If you can afford to buy, and modify a BMW, why can't you shell out 120 for an intake? LOL

Sometimes it's more fun to experiment and learn new things. Why buy an Evo and make it fast when you could just buy a Skyline GTR that already is?

also whats the point in paying 120+ for something you can make for 40 bucks and get relatively the same outcome? unless you're too worried about the "bling" factor...just because something says AEM or INJEN and is shiney doesnt make it a far superior part...youre mostly paying for the bling and the convenience of not having to put out the energy to built it yourself... SLC GOOD WORK. and props for the creativity.

First money was definitely not the deciding factor when doing this. I could have paid the $180 AEM wants for their SRI but I would still been left without a heat shield. I recognize the R&D AEM put into their dryflow filters which is why I bought their filter. For me I felt the 15 in long intake tube that has a 45 degree bend is not worth the remaining $120 AEM is asking. Don't get me wrong though the aluminum piping looks really great but I almost guarantee it doesn't flow that much better than the stock tube which is why I think RRM used the stock pipe for their SRI.

The other SRI's from Injen, RRM, and Fujita don't incorporate the factory snorkel and with how close those intakes put the filter to the engine you can bet you are sucking the air straight off the exhaust manifold. None of them come with a heat shield either. I could buy a crappy heat shield off ebay that attaches under the intake clamp but I think those are garbage.

Like I said before, a CAI is still best design to get the coldest air and you won't need a heat shield. For people with an SRI that would like to block some of the hot air coming from the exhaust manifold a heat shield similar to the one I built will help block that heat. Plus you can incorporate the stock snorkel which help funnel more fresh air near the filter.

And just so you know I did buy the name brand intake for my BMW and paid full price. I just realized later that I could have done the exact same thing for far less.

"which is why I think RRM used the stock pipe for their SRI."

I had asked RRM a couple years ago why they used the stock Rubber piping on their SRI and CAI. They told me it was due to how much the motor moves.

^ Good to know. Thanks