PICTURE OFF-ROAD RACING RIGS roaring across dry lake beds and up rock strewn, eroded mountain passes. You can't identify these rigs, they're tiny pinpoints against a burnt umber landscape, but you can chart their course by the rooster tail of dust that fans out behind them like the contrail of an F-15.
Now get carried away by this scene, and picture your own rig chasing this dust cloud through the desert. Picture that cloud of dust being sucked into your engine, clogging the filter, the finest particles storming the ramparts of your engine, the pistons scraping against the cylinder walls that have been turned into emery boards. Ugh. That's the kind of image that nightmares are made of. It's also the kind of image that undoubtedly spurred the engineers at AEM, of Hawthorne, California, to develop high-tech air filters and performance intake systems.
John Concialdi (JC), the mastermind behind AEM, started the company in 1987, following a stint as lead engineer for Red Line, (the US distributor for Weber Carburetors) where he engineered carb kits for race and street applications. Initially, AEM focused on engineering and tuning; conducting research and development for other aftermarket performance manufacturers, as well as developing its own product line. The company's early offerings, a cold-air induction system and adjustable cam gears, were hot in the sport compact market. From the beginning, Concialdi's theory was that if the products were well engineered, they would sell. They did.
In 1997, AEM changed ownership; Peter and Greg Neuwirth, father and son, purchased the company with Concialdi continuing to oversee the expanding engineering department. The Neuwirths added 23 engineers, bringing the total to 24, and didn't stop there. The facility exploded from 5,000 square feet to 130,000, and staffing grew from eight to 260. The expansion included the development of intake systems for light trucks under the brand name Brute Force. This growth was accompanied by an increased involvement in off-road racing. AEM Sponsorships involved both products and custom tuning to help off-road rigs literally fly over rough terrain.
Larry Ragland, one of off-road racing's perpetual winners since the early 1980s, came to AEM in 2004 in search of better throttle response. Ragland has one of those careers that legends are made of with wins at Pike's Peak, The Mint 400, Africa's Gold Coast and a phenomenal three-peat (1995-1997) at the Baja 1000. He left AEM a happy camper with a custom intake system and enough throttle response to pin him in his racing seat. AEM's tuning expertise extended to his team's Prerunners that had to be able to perform like the race trucks. "Besides 'walking' the race course, explains Kirk Miller of AEM, Prerunners are used as chase vehicles. They have to get a four-man crew to a downed truck as quickly as possible over very rough terrain."
Camburg Racing represents another AEM success story. "Teams running Baja usually go through two, three or even more air filters during the course of the race," says Miller. Camburg ran the Baja 1000 in 2005 with just one of AEM's DryFlow filters. "Camburg ran the entire 1,000 miles on one air filter. All they had to do was take it out, bang the dirt out of it and pop it back in," says Miller
To understand the DryFlow filter's technology, you need a brief review of the technology that has dominated the air filter industry for the last 30 or so years - the oil-based filter. These filters use a fibrous mesh material impregnated with oil. The oil swells the gauze layers and acts like a sticky dirt magnet. "It takes a while to clean these filters," says Miller. "They have to be re-oiled and then the gauze has to fully absorb the oil. The process can take from three to six hours."
Now along comes AEM's DryFlow design. Instead of oil-absorbing mesh, the DryFlow uses a non-woven synthetic material - no weave, no opening for even the finest dirt particles to sneak into the engine. The material filters down to one micron of particulate, removing 98.6 percent of airborne dust in initial efficiency. To get a picture of what that sneaky one-micron looks like, a human hair is around 100 microns thick.
"There's a fine balance between efficiency (how well the filter cleans the air) and air flow," says Miller. AEM designs each filter application to exceed the required air flow by a ratio of 2:1 to 3:1. If the engine requires 500 cfm of flow, its DryFlow filter has a flow rate of 1000 cfm for a higher level of performance. For 4x4s with other performance modifications that increase the engine's demand for air, this extra flow rate is anything but redundant.
The Camburg team's cleaning method - bang the thing against a tire and presto, it's clean - may not be part of the official cleaning instructions, but it's not far off. The medium sheds dirt; the filter is washed and shaken (not stirred) dry. This process takes only about an hour (unless you're in the middle of a Baja race, which would require the more abbreviated method).
The synthetic material has the durability to withstand a lifetime of washings, and is augmented with a lightweight, mineral-reinforced plastic cage that maintains the filter's structural integrity. There's no chance the filter will collapse from high flow rate demands. There's no metal mesh to maintain the pleats, (the design required by gauze filters) and as a result, the DryFlow filter can be twisted and tweaked, or banged against a tire, and still maintain its shape, performing without a hitch. In the words of Miller, "This is one bad ass filter."
The DryFlow is an integral part of AEM's Brute Force induction systems for light trucks. While not technically a cold-air system, which requires routing the filter outside of the engine compartment - (hardly a good idea for off-road applications), the systems pull air from the coolest source available under-hood and incorporates a steel heat shield to protect the filter from high engine temperatures. The inlet tubing is made from mandrel-bent, lightweight aircraft aluminum, chosen, in part, for its rust-free qualities. The more conventional choice of materials is steel. AEM opted for aluminum simply because its plusses far outweighed any issue of heat absorption. The rate of airflow under open throttle negates the effect of material heat soak, according to Concialdi. Performance results from design, not materials, are the key to AEM's Brute Force line. The company employs meticulous tuning of its inlet pipes. Manipulating the length and diameter of the piping incorporates sound waves to increase the air's charge. This isn't a totally foreign concept; we've heard performance exhaust engineers rave about tuning exhaust pipes for maximum flow - that's what AEM does with its intake systems. "Our system barks when you turn the ignition on," says Miller.
AEM hasn't neglected diesel tow vehicles. The Workhorse Heavy Duty diesel intake system uses the DryFlow filter to deliver 33 percent more airflow than the original factory intake. Like the gas-powered intakes, the Workhorse includes soft mounts for a perfect fit even under the most rugged driving conditions.
Equipped with an AEM filter or better yet, a full intake system, off-roaders don't have to worry about the height of their rooster tail. None of the dust that new-found power kicks up will make it into their combustion chamber.
Other AEM milestones are the development of the first stand-alone programmable engine management system which uses the factory wiring harness, and, the development of the first instrument gauge with a built-in wideband, UEGO (universal exhaust gas oxygen) controller and gauge readout. UEGO sensors allow for precise tuning to maintain the best air/fuel ratios. "In the past," says Miller, "high-end race cars used an expensive version of a UEGO sensor. Our product is the first captive, in-gauge system that is affordable for enthusiasts. It works with both carbureted and fuel injected systems and communicates with either the factory computer or aftermarket engine management systems for closed-loop tuning. It puts the information right in the driver's face. If something is going south, the driver has a warning."
The Plug & Play, Engine Management System programs the engine's parameters. It allows any combination of engine controls, power adders or auxiliary devices while delivering spot-on fuel/air mixes and ignition timing for any operating conditions. The beauty of the unit is that it plugs directly into the factory ECU harness with no additional wiring or hardware, and the software is Windows compatible.
Basically, AEM provides high performance at every level of off-roading; from a heavy breathing, high-tech air filter to a full induction system; from a remarkably easy to use engine management system that boosts power and torque, to a UEGO gauge/controller for the true gearhead. When you go with AEM, you'll hit the bull's eye.
View a complete listing of premium AEM products online, or to order by phone call 4 Wheel Parts at 800-284-9840.
