I decided to write up a small article on how I put together the intake for my N/A 04' Coupe Autostick. Cold air intakes are upwards of $300, and while they may have a slight increase in performance over this intake, some may not justify paying double the price for a minimal difference. With this intake you will get smoother shifts if you have an automatic, increased throttle response/torque, and a bit better passing power. Of course it makes the car sound much sportier under heavy throttle... just overall deeper with more engine sound to compliment the exhaust. Although it still pulls hot air into the engine bay (the factory air box is more than likely just as bad), the less restrictive design over stock makes gains. Installation is much easier being up top, not needing to modify, remove, or move anything around, the filter is easy to get to and maintain, and no possible worries of hydro-locking your engine from water.
It's extremely easy to make yourself. After having all the parts, it will take no longer than an hour or two taking your time. I'll list the things you'll need and where I purchased my parts.
(1) 3.5" to 3" reducing elbow
(1) 3" 75 degree mandrel bent pipe
(1) 3" 45 degree mandrel bent pipe
(1) 3" Silicon hose
(2) 4" Clamps for throttle body inlet/reducing elbow
First, go to
http://www.intakehoses.com/ and go to the 90 degree reducing elbows section and pick up a 3.5" to 3" rubber elbow. It will be roughly around $25 with ground shipping. This would also be a good time to get your worm gear clamps unless you already have some. 4" or more should be large enough. You can also pick these up at Lowes for a few cents cheaper. You can get two or five of them depending on if you want everything clamped down extra tight.
Next, head to Ebay and check out this sellers store
http://stores.ebay.com/CXRacing . CXRacing offers 3" pipe and hose kits (listed for randoms cars as intercooler kits). I picked up the black powder coated ones with black hoses, but you can get polished, and choose from black, red, or blue hoses. Their auction also includes tons of T-Bolt clamps. You can use these instead of the worm gear clamps mentioned earlier but they are NOT big enough to use on the throttle body inlet or the reducing elbow so you'll need to buy something larger. Make sure you choose the auction that has the 90, 75, and 45 degree bends and 3" diameter piping.
Lastly, buy the 3" inlet filter of your choice. You have a tad bit of room to play with here, but nothing longer than 5". AEM has closeouts on Ebay on their older filters (comparable to K&N) and are a steal at about $25 shipped. Here is a link to their store
http://stores.ebay.com/aem-outlet
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Alright, now the rest is pretty straight forward. All you have to do is cut about an inch off the bottom of the 3.5" to 3" rubber elbow (the 3.5" side thats connecting to the throttle body inlet) with either a sharp knife or some good scissors. This makes it shorter so it doesn't stick up too far off the engine, helping to clear the hood. Make sure you leave enough room so the clamp wraps around it.
Now insert the 75 degree pipe into the rubber elbow until the pipe clears the heatsheild in the engine bay.
Slip over the silicon hose to the 75 degree pipe.
Insert the 45 degree pipe into the silicon hose, and twist the pipe until it is facing the radiator fan. Mark this pipe just a little bit after the dipstick. It doesn't have to be perfect measurments. Now remove the pipe and cut it with a method of your choice and file and clean down the cut off area.
Baisically at this point your intake is complete. Clean all the piping inside and out, move and twist things around and attatch everything securely.
Test fit your filter and make sure nothing is resting on the a/c lines or near the engine belts. The piping will rest on the engine safely and not harshly rub or damage anything. If you are really handy, you could possibly make a bracket to holt it up attatching to the dipstick area.
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Here are more pictures of the completed product:
http://img267.imageshack.us/img267/2780/05hm1.jpg
http://img134.imageshack.us/img134/9770/06bc0.jpg
http://img187.imageshack.us/img187/9807/07au4.jpg
http://img402.imageshack.us/img402/4831/08bd1.jpg
http://img379.imageshack.us/img379/3875/09id8.jpg
http://img402.imageshack.us/img402/7006/10ju1.jpg
Notes about this tutorial:
Everything said is just my own opinion and personal experience. The filter in the pictures is NOT AEM (I ordered the same product I recommend but experimented with the wrong size filter, so I have to order another one) it's temperary and has a small inlet so it's inserted into the pipe and has no clamp.