Introduction When modifying cars, one of the most common modifications is a modification to the intake tract. Though performance gains are debatable, many people still like the idea of a cold air induction system for the intake sound, the look under the hood, or for any other reason they can think of. When interested in a possible intake, I searched the forums, checked out every company imaginable, and found many conflicting opinions regarding intakes and filter types.
I eventually chose to go with the Cosmo Racing intake from
www.cosmoracing.com. It was the cheapest one I could find that still looked legit. I installed it, used it for about a year, became indecisive, took it out, and made a temporary short ram intake with a paper cone filter (from a 91 Prelude) until I decided which type of intake I wanted for good.
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http://www.318ti.org/gallery/data/753/photo1.jpg Issues The first issue I had to decide on was whether a cloth Cosmo Racing air filter (similar to K&N type construction) would adequately protect my engine. After doing several hours of internet research on filter types, I reached the conclusion for myself that yes, it would protect my engine sufficiently and it was safe to continue use. There are many conflicting opinions on this topic so you have to decide for yourself. Another benefit of the Cosmo filter is the size. It is much smaller than the Prelude paper filter and can fit under the hood a lot better.
The Cosmo intake was decent, but in my mind had a few flaws. Firstly, the filter was routed right behind the driver side fog light. Not a big problem, except for the brake duct is in the way. To install, you have to jack up your front tire and remove it. You have to take out the wheel well liner, and remove the brake duct, run the piping down, and attach the filter from the bottom. It is not terribly difficult, but very inconvenient when you need to clean your air filter or check it every so often. I want a system that can easily be removed from the engine bay without taking wheels off.
The Cosmo system was not very secure. It had a securing bracket, but the only place it could really go was off of the side of cruise control mount. Not hard to do, but essentially you are securing the top 3 inches of the intake while the last 20 inches of pipe rattle and shake around at the bottom. I want something a little more solid.
With the filter all the way down by the fog light, hydro locking your engine can be a concern. Though rare, if your splash guard isn’t working, you can leave your entire car stuck if you hit a deep puddle.
The Cosmo intake consists of two pipes which attach together with silicon sleeves and create a round-about S type curve. I am not an expert on fluid dynamics, but I like the idea of making the air travel the least distance. I wanted a straighter path for the air to flow with the least amount of curves.
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http://www.318ti.org/gallery/data/753/photo2.jpg Materials In the Cosmo racing kit, you have several parts:
1. Short elbow pipe
2. Long straight pipe with elbow at end
3. MAF adapter plate with hardware
4. Two mounting brackets with hardware
5. 2 silicon sleeves
6. 5 clamps
7. Air filter
For the modified Cosmo intake, you will only use
1. Long straight pipe with elbow at end
2. MAF adapter plate with hardware
3. ½ mounting brackets with hardware
4. ½ silicon sleeves
5. 3/5 clamps
6. Air filter
Notes The instructions in this write up are based on the assumption that you already have an idea of how to install an intake. Chances are if you purchased this intake, you already have it installed when you are reading this, or you are merely reading this for fun and you don’t need full instructions anyway. The Cosmo Racing kit comes with full instructions that are easy to understand, which will be similar to the install of this intake. If you have any specific questions, feel free to ask me.
I have several photos of the intake set up, which help the words make sense a bit better. Use both.
My measurements were done specific to my car. Although they should be the same on an M44 and an M42, you may want to double check any cuts or drills to make sure. Better to measure twice and cut once then to have a pipe that you wish was longer.
My Solid Works models are not drawn to scale. They are just to help visualize what I am talking about.
Procedure Start off by removing the air box and the associated plumbing. It isn’t hard to do. Pop some clips, loosen some nuts on the cruise control mounts, and you should be good. Go ahead and attach the MAF adapter plate to the MAF with the included hardware. The adapter plate looks like this.
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http://www.318ti.org/gallery/data/753/photo3.jpg You will need to remove the two horns. I don’t remember where both of them originally mount to, but one is right above the brake duct. You may need to get it from underneath by removing the wheel well liner and brake duct. This is done by taking your front driver side wheel off and unscrewing the wheel well liner. Remove the horns from the wiring harness for now and you will remount them later. One horn has a longer wire, which is important for noticing later when you remount them. If you want, you can cut a small flap in the top of the brake duct. Be sure to pin the flap in place with some tacks or small screws so the flap doesn’t bend up or close. This will supposedly route cool air from the brake duct up to where the filter will be. I didn’t do it, but I don’t think it could hurt. Reinstall the brake duct, wheel well liner, and wheel.
Now you should have a pretty big empty space where your air box used to be, and you should see a triangular shaped hole by the radiator and behind the head light that goes down to the brake duct and behind the fog light area. The goal of this intake is to land the filter right inside that hole above the brake duct.
Right near that hole, there is a threaded spike that one of the horns was mounted to. It originally points down, which is the reason you had to remove the wheel to get the horn off. It is connected to the frame of the car by thin metal brackets which can be bent. Using clamping pliers of your choice, grab the spike and pull it so it is pointing straight up. It may be difficult to get the right angle on it, but it didn’t take me too long. Just get it close to the side of the hole so the filter has more room, and keep the threaded spike pointing up so you can easily mount a horn and secure the intake. I was able to do this with clamping pliers from above in the engine bay, but you may want to try it while the wheel is off if you think it may give you some trouble.
The next step is to start modifying the Cosmo kit. First, find the long intake pipe and cut 2 ½ inches off of the straight end. Use a hacksaw. Try to make it as straight as possible, but due to silicon sleeves it is alright if it is a little off. Use a file to clean up the edges and get any loose particles of aluminum off the rim. You would hate to have solid aluminum particles sucked into your engine since it will be up stream of the filter.
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http://www.318ti.org/gallery/data/753/photo4.jpg At this point, you want to modify the securing bracket. Find the bracket that has only one hole, and drill another hole about an inch down the bracket.
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http://www.318ti.org/gallery/data/753/photo5.jpg You are now ready to install. Slide the filter on the curved end of the pipe with a clamp very loosely around it, with the securing bracket already hooked to the clamp. You want to slide the filter/clamp/bracket into the hole at a slight angle. Be careful not to bump the filter into the threaded spike, which is now pointing up wards. The straight end of the pipe should angle up right to the MAF adapter plate, which you will connect with two clamps and a silicon sleeve. Attach the securing bracket and the horn with the longer wire to the threaded spike that you bent to point up. Tighten up the clamp around the bracket and filter. Tighten up the clamps on the silicon sleeve. Tighten up the nut that goes to the threaded spike with the horn and securing bracket. Mount the horn with the short wire with a bolt and a nut on the cruise control mount. The cruise control is originally mounted on threaded spikes that stick out of the air box. The Cosmo kit should provide you with a bolt and a nut for each of the two cruise control mounting points, since the air box is being removed.
Make sure all the clamps, nuts, and bolts are tightened. You should now have an awesome intake with the filter right above the break duct, a solid steel securing bracket bracing the filter, and the horns mounted in a new location.
Modified Cosmo Cold Air Intake System 
Threaded Mode