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Presented by motoring|underground

Written by Ivan Diaz
m|u Editor-in-Chief

Photos by Sean Hamilton
m|u Feature Photographer

Produced by Hollis Lee
m|u Feature Producer

January 28, 2005

Ahh, winter is upon us once again. The inclination of our fine planet has, like clockwork, begun to chill us through and through. The frigid interior of my car has begun to creak more, the dampers have stiffened, and for some reason, my MINI mysteriously seems to have a lot more punch than it did just months ago. Am I just being more eager with the accelerator? Is my butt-dyno miscalibrated? The mystery continues…

Inside your engine, a complex dance occurs with every puff of exhaust. In what is commonly referred to as the Otto Cycle (named after German engineer Nikolaus Otto), your engine transforms explosions into motive force that turns the driven wheels of your MINI. The four strokes:
  1. During the intake stroke, the intake valve at the top of the combustion chamber opens, allowing the falling piston inside the cylinder to draw a mixture of air and fuel from the intake manifold. As this induction stroke comes to a close, so do the intake valves, sealing the combustion chamber in preparation for the next step.
  2. As the piston reaches the bottom of its travel and the crankshaft makes another swing below, the piston begins to rise again, marking the beginning of the compression stroke. The mixture of fuel and air is compressed tightly, taking what used to be 400 cc of this already-densely-compressed explosive concoction (thanks to our friend, the supercharger) and compressing it further. In the MINI Cooper S, the mixture is compressed to a ratio of 8.3 to 1 at the very top of piston travel, known as top dead center, or TDC. Suddenly…
  3. A tiny lightning bolt strikes within the densely packed cloud of air and fuel, sending a flame front sweeping from its center that expands with massive force against the piston top, thrusting it downward against its connecting rod reign and turning the crank in what is commonly known as the power stroke.
  4. For the exhaust stroke, the exhaust valves open as the piston reaches the bottom and begins to rise again, pushing the fiery elixir of exhaust gasses into the exhaust manifold. The exhaust valve closes, and as the piston reaches TDC, the intake valve begins to open, starting the cycle anew.
Additional power can be generated from any stroke of the Otto Cycle, either directly by reducing restriction of flow or volume, or indirectly by reducing parasitic losses. For the TEAMMIGHTYMINIZ Intake Shootout presented by motoring|underground, our power-hungry Hollis Lee chose to focus on what is not only the first step in the cycle, but most commonly the first step in what is often a long, expensive addiction to tuning—the intake.

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Contrary to all of the marketing hype that you read in shiny magazine advertisements promising uncompromised performance, every vehicle intended for mass production undergoes a rigorous research and development cycle in order to find the best compromise between performance, drivability, reliability and comfort. The supercharged MINI Cooper S is no exception. The MCS features an Eaton roots-type supercharger capable of producing 12-14 psi of boost in stock trim. With this boost comes an unmistakable scream as air is beaten into submission in the name of horsepower. Performance-minded individuals love nothing more than this high-pitched howl, which rings true to passengers and pedestrians alike. To the average driver, this intrusive sound serves only to interrupt cell phone conversations and take the “smooth” out of their smooth jazz. For this reason, the induction system of the MCS is designed to subdue most of this sound with a complex, tangled network of corrugated rubber tubing, leaving only a faint whine to let you know there’s something different under the bonnet.

Fortunately, the automotive aftermarket offers a diverse variety of intake systems to provide enthusiasts with different levels of tuning and sound. They range from a slight bump in response and whine, to an all-out racing system designed to optimize high-end horsepower and indelibly resonate the sound of forced induction into your ear drums.

The cold air intake’s name is a bit deceptive. One of its primary functions is to provide the engine with colder air. The theory is that colder air is denser, and denser air contains more oxygen molecules given the same volume. More oxygen molecules being crammed into the intake manifold mean more fuel molecules can be combusted. Logically enough, roasting more fuel molecules makes for a stronger shove on the top of the piston, which in turn develops more power. Why is the name deceptive, then? Although cooler, denser air does contribute to some of the power gains you’ll witness later in this article, the primary reason most aftermarket intake systems develop more power is that they improve the flow of air through the induction path and further reduce restriction by providing a larger air filter. By reducing this restriction, the engine and supercharger waste less power pulling air into the combustion chamber, and in turn, transmit that power directly to your front wheels in a deluge of tire smoke to show that Mustang just how cute your MINI really is.

Since MINI owners began tinkering with their little beasts, there has been no shortage of heated discussion, in person and on the Internet, about what works and what’s fluff when it comes to the subject of making more power in the complex MCS powertrain. Since tuning sometimes seems to be more religion than science, these heated discussions often produce no hard evidence as to the true gains to be had from the most popular tuning methods. Having grown weary of such flame wars, TEAMMIGHTYMINIZ and motoring|underground decided to put the MINI community’s favorite forum battle munitions to an objective, scientific test to see who comes out on top. Now, the TEAMMIGHTYMINIZ Intake Shootout presented by motoring|underground.

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The Test

In order to preserve the objectivity of the Shootout, we devised a procedure that would provide each intake with the same set of environmental parameters. For starters, all testing was performed on Hollis Lee’s bone-stock 2005 MINI Cooper S, ruling out the inherent differences between supposedly identical cars that result from production tolerances and rolling product updates. To keep tuners from pulling any tricks from their sleeves, we invited James, technician and co-owner of Creative Autoworks (, 858-279-8900) in San Diego, CA, to perform all installations.

The only true way to draw a scientific comparison is to generate hard numbers, and for this part of the process, we chose to perform our dynamometer testing at JBA Racing (, 888-JBA-5570) in San Diego, California. Much to our convenience, they were generous enough to squeeze us in to twist their Dyno Dynamics rollers for the day, despite having their last minute preparations for SEMA Show 2005 occurring in the background. All dyno figures are SAE corrected, ensuring that ambient temperature, relative humidity, and barometric pressure do not affect the results.

Here’s how we tested Hollis’ MINI:
  1. Take the MINI on brief drive to bring it to operating temperature.
  2. Roll the MINI onto dyno, pop the bonnet, and position a large fan to properly feed the intercooler with ambient air during the test, thereby preventing heat soak.
  3. Reset the ECU by leaving the battery cables disconnected for 5-10 minutes.
  4. Start the car and make the first two dyno pulls with the stock MINI Cooper S specifications, as a control data set.
  5. Turn off the vehicle.
  6. Install the intake system to be tested.
  7. Reset the ECU again by leaving the battery terminals disconnected for 5-10 minutes.
  8. Start the car and make two dyno pulls for the installed intake.
  9. Take the car on a brief test run to evaluate driveability and real-world performance potential.
  10. Go back to step 5 and repeat the process for each intake.
The Contenders

Indeed, the selection of cold air intakes available for the MINI can be a bit overwhelming, with every company itching to show the world their take on what free air flow and aggressive sound means to them. Fortunately for us, most MCS intakes, despite small variances in design, fall into three major categories. We’ve managed to test what we feel is the best representation of each design from three of the community’s most popular manufacturers. Without further adieu…

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Stage 1: The intake for the masses.

Helix Minisports (, 877-Helix13) was one of the first MINI tuners to bring a cold air intake for the MCS to market. As the MINI community [not Mini] was in its infancy, the market demanded an intake that would be easy to install and provide a solid boost to acceleration and sound without unnerving new owners who were worried about ambitious service advisors on their first scheduled visit to the dealer. Helix hit the nail on the head and brought to market an intake that fit the bill perfectly, sealing the deal with a low price of $199.00. The Helix intake provides an excellent improvement in response along with a symphony of supercharger and engine sound that encourages your right foot. Consisting of a large, pleated-cotton conical air cleaner element, a sturdy steel heat shield, and a replacement cowl plate that allows additional air to be fed to the filter via the cowl vent on the base of the windshield, this design follows the engineering philosophy of keeping it simple.

Installation took approximately 15 minutes to complete, and required a few basic hand tools and a set of Torx drivers. Along with James, we concluded that this kit could easily be installed by just about anybody who had the tools available to them.

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Stage 2: Taking it up a notch.

Not to be outdone, newcomer Alta MINI Performance (, 503-643-4667) created their own version of the cold air intake, which combines easy installation and an innovative design that delves deeper into the induction system. It replaces much of the sound-deadening corrugated rubber tubing in the factory design with a wide-mouthed custom inlet hose that not only improves airflow, but also serves to provide a bit of style to the all-business engine compartment of the MCS. Pricing for the base kit, without the big-bore inlet hose, competes directly with the Helix Cold Air Intake in both design and price, coming in at $199.99. The addition of the custom inlet hose brings the price to a still-competitive $259.99, well worth the price of admission for the improved air flow and throttle response characteristics of the complete Alta Performance Intake System.

As this system goes just a few steps beyond the simplicity of the Helix Cold Air Intake, installation took about 20-30 minutes and required a little bit of elbow grease to work the custom inlet hose into place.

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Stage 3: Not for the faint of heart.

There’s always someone in the crowd. The one who would love nothing more than to have a race car, and is willing to sacrifice the civility of their precious machine a bit more than your average Sunday tuner. For this type of MCS owner, this means thoroughly redesigning the induction system of his or her engine.

To extract the maximum amount of power and reveal the true nature of the beast’s wail, the Air Gain System from M7tuning (, 562-608-8123) does away with all of the corrugated tubing and convoluted twists of the factory induction system and straps a sizeable blue custom filter directly to the throttle body. With response approaching that of a throttle-cable-equipped engine, and the hiss of the throttle butterfly cracking open at the whim of your foot on the accelerator pedal, the throttle body feeds the supercharger air through an enlarged “AGS Tube” that replaces the pinched throttle-body-to-supercharger-duct tube originally designed to subdue the telltale whine of a Roots supercharger at full song.

With custom pieces and lengthy R&D cycles come a higher price. The M7tuning Air Gain System is no exception, sitting at the top of the heap with a not-unreasonable base price of $299. For an extra $50, you can shield the filter from the heat of the engine compartment with a carbon fiber heat shield, or opt for standard gel-coat plastic material if carbon fiber isn’t your cup of tea. For $649, the most aggressive package available from M7’s AGS line is the AGS Pro. This MINI tuner’s dream includes a 62mm throttle body, designed to add even more immediacy to the throttle response of the AGS. To keep the battle (and price spread) tight, we opted to use the non-Pro AGS for our testing.

Throttle response that stomps the competition and the shrill of a naked supercharger for only $40 more than the Alta? There’s got to be a catch, right? Right. Installation of the Air Gain System is no small feat. Going far beyond the simple and easy-to-reach bolt-on installation of the Helix and Alta systems, M7’s intake requires the removal of the front bumper, aluminum cross-member and all, and the replacement of a radiator hose in order to help it clear the newly re-positioned throttle body. Fiberglass heat shielding is added to block heat from the radiator fluid inside the hose. In total, installation can realistically take 2-3 hours for the beginner brave enough to take on the task at hand. Installation by an experienced MINI tuner, though not required if you know your way around a tool box, is definitely recommended. The M7 AGS is about as invasive as a cold air intake can get.

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The Results

Before we get into the final judgment on these fine intakes, I must stress one important fact: Dynamometers provide two measurements, our good friends Torque and his trusty stablemate, Horsepower. They cannot measure the throttle response, driveability, sound, and grins provided by sheer driving enjoyment in the real world, on warm tarmac. With this in mind, we’ll move on to the results…

As our shiny Dark Silver test subject eagerly rocked into place on the rollers, our audience huddled together to witness first-hand what a bone-stock MINI Cooper S could produce, after the mild revisions made to the MINI for the 2005 model year. Impress, it did. Despite a factory crank horsepower rating of 170hp, Hollis lucked out as his MINI produced an astounding 168.2 hp to the front wheels! According to our calculations, using the 15% figure that is widely regarded as the powertrain efficiency loss percentage for an MCS, Hollis’ MINI developed roughly 198hp to the crank, well above the conservative numbers touted on the factory specification sheet. We initially considered the possibility that the dyno was miscalibrated, but after analyzing the results of various MINIs throughout the event, we felt confident that the Dyno Dynamics dynamometer was producing relatively accurate results. As lofty as those figures may be, we were far more interested in relative numbers than absolute numbers as we continued with the next round of testing.

With our baseline scrawled in our notebook, we moved on to our first contender, the Helix Minisports Cold Air Intake. With the Helix piece being the least invasive intake in our challenge, we expected it to also have the least gain in power of our three. As the charts printed from the Dyno Dynamics computer, our hypothesis looked to be confirmed by a relatively mild bump of 2 hp, bringing the total to 170.3 hp @ 6500 rpm and 166 ft/lbs of torque at a significantly lower 3800 rpm, for improved mid-range performance.

A test drive of the Helix intake immediately revealed a slightly more aggressive supercharger note to compliment its improved response, especially at speed (3rd gear and up), with the highest bump in power occurring at freeway speeds. Based on these observations, we have a feeling that the true potential of the Helix Cold Air Intake cannot be measured on a dyno. The Helix unit uses a combination of the traditional intake path and the newly added cowl intake system, whose benefit in both intake volume and lowered temperatures can only be generated with the accompaniment of air rushing into the cowl and intake duct at speeds above 60 mph.

Next to step up to the plate was Alta MINI Performance, bringing with it a sexy touch of red in the form of big-bore intake ducting and a foam performance air filter. Of all three, this kit is decidedly the most in-your-face piece, begging for your attention in the engine compartment, for better or for worse. Shrieking to a maddening song at redline, the Alta managed to edge out the Helix in the war for horsepower with a final figure of 172.2 hp @ 6500 rpm. Perhaps more importantly, the Alta reached its 167 ft/lbs torque peak at 3700 rpm, 700 rpm lower than the factory unit, but only 100 rpm lower than the Helix.

Once off the rollers, the Alta proved its big-bore theories with superb response and satisfying thrust that also seemed to suggest higher horsepower and torque numbers on the butt-dyno than the dyno laboratory numbers. Thanks to the larger pathways provided by the upsized custom tubing combined with the open cowl design, the Alta produced a slightly throatier note that would be complimented by a deep, rich exhaust.

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For the hot-rodder in everyone, there’s the M7 Air Gain System. A little rough around the edges, and a pain in the you-know-what to install, but our labors paid off in the end with a solid victory in the power wars. The AGS managed to up-stage the Alta by three horsepower, rising above the rest with 175.0 hp @ 6500 rpm and a 169 ft/lbs peak torque rating, available at 3800 rpm. As the charts indicate, the M7 and Alta are nose-to-nose until about 4400 rpm, when the M7 begins its ascent to rise above the Alta by three horsepower. This results in a total delta over stock of 6.8 hp and 3 ft/lbs of torque.

The test drive confirmed the figures, as the AGS-equipped MINI offered excellent flexibility in the mid-range, showing every bit of its torque peak by 3800 rpm, a significant 600 rpm lower than the stock intake system, but 100 rpm higher than the Alta. With the throttle body pinned open, and the engine singing along above 6000 rpm, the sound of the supercharger wailing is enough to turn heads within a 200 yard radius. Its mystifying blend of soprano notes bounce readily off of stone canyon walls. This intake practically demands a downshift in tight tunnels. In other words, this intake not only performs, but with the sharp hiss of its throttle butterfly, it draws plenty of attention and credibility in an increasingly blow-off-valve-obsessed tuning community. Those interested in subtlety need not apply, as the AGS is most decidedly the extrovert of this fiercely competitive crowd.

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The Verdict

More than providing concrete numbers and subjective impressions through the eyes and ears of our staff of MINI-crazed tuners, the TEAMMIGHTYMINIZ Intake Shootout presented by motoring|undergroundproved one thing: Since its inception with the launch of the R50 Cooper during the 2002 model year, the MINI community has grown to encompass the desires and needs of every tuning level, from the daily commuter to the weekend track contingent alike.

The Helix brings to the table the pinnacle of simplicity in engineering, and fits the bill perfectly for those wanting a little bit of everything. However, this desire to please everyone results in an intake system that appears to be outclassed by the more ambitious competition when it comes to a head-to-head comparison on a stock vehicle. Higher torque numbers and a broadened torque band do contribute to a substantially improved driving feel, and considering the massive conical air filter, we feel this intake might produce a stronger difference on a car equipped with a few more go-fast modifications.

Swapping the performance and comfort ratings, we come to the M7 Air Gain System. With emissions inspections being a consideration in many states, especially the heavily-MINI-populated state of California, the M7 system’s difficulty in installation, and therefore the complexity of reverting it to a stock configuration for service and emissions testing, may be a bit more than most want to contend with for their daily driver. It’s loud, the hiss of its throttle body ajar as it openly advertises your MINI’s level of modification for the world (read: law enforcement) to hear. It’s virtually guaranteed to elevate the pulses of onlookers who are surprised to hear such a maddening howl out of your diminutive little beast. The M7 AGS slams it out of the park with a level of performance and throttle response that would make many a carbureted car envious. If you’re ready to take your car one step closer to becoming the race car you’ve always dreamed about, the M7 AGS is undoubtedly the king of the hill. If sheer performance and an aggressive, in-your-face demeanor are what you’re looking for, add the M7 AGS to your MCS’ custom specification sheet.

For the rest of the MINI tuning contingent, the Alta MINI Performance Intake System holds down the middle ground. It offers a solid kick in the pants, a reasonable price, and elevated sound levels for the tuner who wants to take his MINI to the next level without compromising comfort and streetability. The ability to bring reasonable sound levels, the option to swap the intake for the stock parts in a moment’s notice, and power and torque levels that ardently nip at the heels of the M7 Air Gain system make for the most well-rounded package currently available from the MINI aftermarket. The jury has reached their verdict: We’d like to present the winner of the TEAMMIGHTYMINIZ Intake Shootout presented by motoring|underground, the Alta MINI Performance Intake System. µ

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