AEM Cold Air Intake for the SVT Focus

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Cold Air Intakes 101

Automotive manufacturers have to design automobiles, even those with a sporting pedigree, to a certain standard. Therefore, most original equipment (OE) parts take into consideration a variety of possible scenarios that may arise during the life of a particular part. Since there is no way to predict exactly what each individual end user's needs and application will be, a common denominator must be adhered to. To an enthusiast, this often means that performance is sometimes compromised for the sake of things such as reliability, noise and fuel efficiency.

However, you may (like many enthusiasts) be less hesitant than the average driver to shift this compromised balance more toward one end of the scale in the quest to squeeze that little extra bit of performance out of your car. There are a few well-known items that most people immediately think of when they want to begin the transformation from '100% stock' to something a bit more energetic. Many people immediately consider a new exhaust. However, fighting for the top of the list for first must haves with today's enthusiasts has got to be a freer-breathing intake, sometimes referred to as a Cold Air Intake (CAI). More on this later.

The reason the above items are so popular is that they are fairly economical. And, they can usually be installed by someone of average mechanical aptitude in a couple of hours with common hand tools. Also, they usually provide a fairly decent "bang for the buck." Because, as complex as today's engines are, there are some fairly simple principles at work. If you look at your car's engine as a big pump, which essentially it is, then the concept of more/faster in - more/faster out makes pretty good sense. If this is still a bit fuzzy, then think of a heart (or lung) of an athlete and you'll start to see the light. Physics dictates that if a pump can bring in more volume and expend more volume faster, then the performance of the pump will increase. Apply that principle to that big pump sitting under the hood of your car and bingo, you've probably just made some additional power!


About AEM

Advanced Engine Management, better known as AEM, has been a staple in the Honda world almost from day one. They have become one of the largest, if not the largest, manufacturer of aftermarket intakes in the sport compact industry. Being a pioneer in the industry means that AEM can rely on their vast experience, data and testing to produce parts that have been tuned precisely to each individual application. They factor in things like intake tube length and diameter to ensure their part performs optimally. And, every AEM air induction system is either C.A.R.B. exempt, or pending C.A.R.B. exemption (50-state legal). That's something to think about in today's world of ever-tightening emissions regulations.


The Kit

When the kit arrived via UPS we were impressed before we even opened the box. It shipped in a solid box that had held up well during the long, cross-country journey. Frankly, we've received parts in the past that were literally sticking out of the box due to improper packing or just plain cheap packaging. It's no fun dealing with a part that's been damaged in shipping. It's nice to know that AEM intakes arrive in one piece. The box is also printed with clean, color AEM graphics. Sure, it's a small thing, but it's the kind of attention to detail that reinforces in your mind that you've made the right decision and that AEM cares about 'end-to-end' quality.

Once you open the box, you'll find that everything is packed nice and secure. You can tell this company has shipped a lot of intakes and knows what it takes to make them arrive safely. What you'll also find is that every part you'll need is there. That may sound like a no-brainer, but we've seen other kits arrive with missing hardware, or items that had to be modified before installation, etc. It's nice to know that you won't have your car torn down only to realize you're missing a hose clamp or bolt. Still, double check all your parts with the included parts list before you begin. Every company makes mistakes now and then.

The individual pieces themselves are all of a very high quality. You can certainly tell that AEM has intakes down to a science. This particular intake, comes in one of 4 finishes/colors: Red, Blue, Silver or Polished. We chose Silver for that custom-made "works" look. All the pieces were pristine and it's up to you to keep them that way during the installation process if that sort of thing matters to you.

Also included, thankfully, is a very detailed set of installation instructions, some of the best we've seen. AEM also includes a license plate frame and a couple of stickers. Another nice touch.



Installation

We thought about providing a step-by-step installation process for this kit. But, to be honest, the included instructions are so comprehensive that we really wouldn't be adding much. As they say, if it ain't broke...

We will, however, throw a public service announcement in here as a reminder. Remember to disconnect your battery's negative power cable before you begin.

What we can tell you about the installation is that it's fairly straight forward. There are some stock items you need to remove first. Some of them you will re-use, others need to be removed simply to give you better access for the installation. This kit has, obviously, been well thought out, and if you are the least bit mechanically inclined, you shouldn't have any problems or surprises.

One warning we'll impart on you concerns the Mass Air Flow sensor (MAF) and its installation. First, the MAF is a somewhat delicate piece of (expensive) equipment. Handle it with a bit of care during the removal/reinstallation process. We do not recommend using the OE MAF mounting screws in the AEM piece. The stock piece is composite plastic, and the AEM tube is alloy. You may want to source your own fasteners for that particular part before you begin the install. Some cap head allen bolts will more then do the job, and they look trick.

The simple fact that we are replacing the restrictive OE air box and filter with a much less restrictive, free flow unit should increase power. But, there's more.

As you see in our accompanying photos, the new intake takes an almost 180 degree nosedive once it leaves the throttle body, bypassing the stock air box location completely. The sole purpose of this radical plunge is the search for cooler air. Remember earlier when we referred to this induction system as a "Cold Air" intake? Why are we looking for cooler air? Once again, for those of you that didn't pay attention in your high school science class, the cooler the air, the denser the air. That means if you can lower the temperature of the air going into your engine, the more volume of said air you can cram into the same space. Remember, our 'more in/more out' pump example?

You'll also see from our photos that at the end of its journey, the intake places the air filter low, under the car, near the driver's side wheel. This is a fairly common place for long-tube intakes to terminate. The advantage is that we are introducing air in a location remotely located from the engine itself, which, of course, is much cooler. Also, you'll remember that we mentioned that AEM is very diligent about tuning the length and diameter of the tube. This helps make sure that the air going in is also traveling at a proper velocity. We'll stop short of calling it a "ram air" effect, but you get the idea.

Recalling an earlier passage in this review, we mentioned that performance usually comes with some trade-offs. In the case of long-tube intakes, there are basically three things to consider. The first usually isn't even considered a negative by enthusiasts. The stock air box is designed to be quiet. That's because most average people do not care to hear the sweet rush of induction that is the very life's breath of the modern automobile. They really don't know what they're missing. The freer-flowing air filter and tuned intake pipe will make their presence known the first time you put your foot into it. It's not overly intrusive, and if you're like us, it will be music to your ears.

The second and third things that you need to be made aware of is that since we've replaced the stock, sealed air box with a filter that is exposed to the elements, you need to be a bit more diligent. You will need to keep an eye on the filter at regular intervals and clean/re-oil it when necessary. The more severe your driving conditions the more often this will need to be done. Also, and this is the one you need to be very aware of, is that you have now relocated the "mouth" of your engine several inches lower then it was originally designed. Why is this so important? Because, as the engine's mouth, the intake can not only ingest air, but also water. Normal rain and atomized water from road spray should be nothing to worry about. But, when confronted with standing water, think twice.

Trying to navigate through anything more then a couple of inches, even slowly, can cause a sufficient enough amount of water to be sucked into your engine. And, when we referred to your engine as a pump, we weren't kidding. The volume of water your intake can suck in a second is amazing. This will produce a condition known as 'hydrolock,' and it's not something you ever want to encounter. Worst case scenario is that you will do thousands of dollars worth of damage to your engine. Even the best case scenario will leave you stranded. So, if you encounter standing water more then a few inches deep, do yourself a favor and find another route.








Conclusion

OK. We've told you about the kit itself. We gave you some tech tips and warnings. Heck, we even dropped some science on you. But, of course, you purchase a cold air intake for one main reason...to make more power! So, how does it fare? What's the car like to drive with it installed? Below you'll find actual dyno sheets provide by AEM. Here, in a nutshell, is what they say: measured at the wheels (so accounting for driveline loss) the intake generated 3 additional peak HP and 2.2 peak lb-ft. of torque. You will see that both the HP and Torque curves are raised over almost the entire rev range with the largest HP gain (5HP) coming at 7,250RPM and the largest torque gain (4.9 lb-ft.) coming at 3,750RPM.

While those numbers may not look like a lot viewed alone, they are real-world gains. AEM is not into making wild claims about their products. These numbers are typical of most cold air intakes, when they are installed alone. The intake is just part of the equation in making additional "bolt-on" power. The intake will respond well when coupled with other common items such as a freer-flowing exhaust, underdrive pulleys and adjustable timing gears. ECU remaps are also a popular addition to the power formula.

What you get with the AEM long-tube, cold air intake is one piece of the puzzle to increasing your car's performance. The most apparent improvement is the raised power throughout the rev range, which makes the car more 'alive'. The torque gain at 3,750RPM is noticeable, as this is where a large majority of street driving takes place. The additional horsepower at the top of the range is also a welcomed addition when accelerating through the gears.

All in all, this is a quality part from a company that has a history of producing solid performance parts for the sport compact market. After our time with their CAI, we can see why AEM earned the reputation as one of the best in the industry.