With each redesign, SUVs seem to become more and more powerful from the factory, which leads to higher towing numbers, and sometimes quicker acceleration, but this is not always the case. With increasing pressure to make SUVs as safe as ever, many companies are loading them up with safety equipment, such as more capable bumpers, stability control systems, and a whole host of airbags. With each of these safety items comes more weight, and therefore more mass to move around. In most cases, SUVs are becoming more powerful from the factory to keep the driveability the same and make up for increased weight, and not because the manufacturer wants to jump into a torque war. But even with increased power, loading up your SUV for a weekend getaway with the family and maybe even a trailer, the need for more power becomes readily apparent, especially when pulling up a grade. Fortunately for modern SUV owners, there is a plethora of companies out there catering to our needs by providing cost-effective parts that are easily bolted onto wring the most performance from your engine.
Direct Replacement Air Filter
Most SUVs, and vehicles in general, come from the factory with a paper air filter element. While paper elements are good at filtration and are cheap to mass-produce, they do not allow an optimal amount of air to the engine, and are not as efficient as a high-performance filter media would be. Most high-performance filters are made of either foam or layers of medical-grade cotton gauze, lightly oiled and behind a mesh screen to allow more airflow, yet trap any unwanted airborne particles. These filters are direct replacements for the OEM pieces, and have the additional advantage of being cleaned and reused, offsetting the initial premium in price.
The last part of uncorking the engine is getting those exhaust gases out after they leave the headers. After-cat exhaust systems not only help to build power, but delight the ear with sounds of your engine humming along. Factory exhaust systems are designed with a quiet tone in mind, and that often means a restriction in flow. For many of us enthusiast, we want to hear a sporty exhaust tone with power-aiding, free-flowing exhaust. An aftermarket after-cat system is the best way to achieve this goal.
The next step after a drop-in filter would be to go with a full intake kit. The intake takes a conical-style high-flowing air filter, and adds lower restriction and tuned-to-perform tubing. High-end intake kits also provide a heat shield to prevent the engine from sucking in less powerful heated engine bay air. Getting more air into the engine is key to getting more power, and intake kits use a larger filter with an increase in surface area over stock, along with a straighter path to move larger volumes of air. Your SUV's computer will be able to compensate for the increase in airflow by adjusting the fuel curve and timing, and most kits are smog legal. The one major drawback to intake kits is the sucking noise that can be heard in some applications.
Performance pulleys work by slowing down the speed of your accessory drive, freeing up some parasitic horsepower, and giving a slight increase in fuel economy. Be aware that slowing your accessory drive system by too much may cause some charging issues with the alternator, so make sure that if you go to pulleys, you size them correctly.
Once you have an intake and you are cramming a lot of air into the motor, a set of smog-legal headers to replace your stock exhaust manifolds will help to pull those gases out of the engine more efficiently, while also boosting power and leaving your necessary catalytic converters and O2 sensors alone. Headers come in many shapes and styles to help boost power and torque in different spots of the powerband. Performance headers are usually fabricated from steel, rather than your SUV's cast-iron factory pieces. Both stainless steel and ceramic-coated versions are popular because of their heat resistance and increased durability over traditional headers.
Computer Chip/Engine Programmers
When uncorking your engine with intake, exhaust, and headers is not enough, it may be time to consider a computer chip or an engine programmer. Chips and programmers adjust your air/fuel ratio and adjust timing curves, and sometimes will improve shift quality by upping line pressure and adjusting shift point on automatics to compensate for the new-found power. In order for these adjustments to work without causing potentially damaging pinging or pre-detonation inside the combustion chamber, most computer products require you to switch to the more expensive premium grade fuel. While better fuel economy often offsets the cost of premium fuel, some people are just not comfortable with the switch. Some of the high-end chips and programmers will also adjust your speedometer and top speed limiter to compensate for larger tires.
Quality ignition wires can help an ignition system to work more efficiently by delivering a hotter spark because of their lower resistance. You may not see an increase in horsepower from quality wires, but you will see a more consistent spark under all conditions, a higher durability with heat-generating headers, and a better underhood appearance.
Throttle-body spacers can be used in conjunction with most intake kits. Throttle-body spacers work by causing a spinning action of the incoming air-charge as it passes through the throttle body. This spinning air charge has a higher velocity and causes the fuel mixture to burn more efficiently, adding to better midrange power and economy.
For the ultimate in performance for your SUV, the best product you can buy is a bolt-on supercharger kit. Safely offering an excess of 50 percent more horsepower and torque over stock, a supercharger works by compressing the air charge, forcing more air into the engine to increase power. The best kits come with new fuel injectors to prevent your engine from running lean, along with a high-flow fuel pump and fuel management unit. There are several different designs of superchargers, from centrifugal to screw, from geared to belt-driven, and everything in between. More and more SUV manufacturers are finding that supercharging is an economical way to increase power, and are taking a cue from aftermarket supercharger companies. If your truck did not come equipped with one from the factory, a blower is a valuable addition and one of the best ways to increase performance. Installation, while generally a bolt-on affair, is usually recommended to be done by a professional, and can take anywhere from four to 10 hours.
An electric fan is a popular way to free up horsepower by eliminating the mechanical fan. In fact, many new SUVs come from the factory with an electric fan setup already installed. Apart from being more efficient in general, an electric fan can turn on and off a predetermined temperature, and can better match the needs of your cooling system than a mechanical fan. Electric fans also have the advantage in packaging efficiency, and are able to draw more air than its mechanical counterpart.
If you are a gadget junky and plan to load up your SUV with all of the latest electronics, such as a mobile entertainment system, killer stereo, navigation, lighting, and the all-important PlayStation 2, you will definitely get your money's worth by upgrading to a high-output alternator. When all of those items are added to a stock electrical system -- a load placed on the engine -- it will make it work harder to compensate for the increased electrical draw and, most likely, the stock alternator will not be able to take the load. High-output alternators can also take the increased heat of a performance engine.
Aftermarket ignition systems provide a hotter spark, which result in a cleaner burn in engines -- especially those equipped with a supercharger. For the best results, multi-spark units are available, and most performance ignitions have a longer-lasting spark than the stock one. There are aftermarket ignition systems tailored toward daily driving, racing, towing, and even off-roading. Each of these use-specific modules is custom tailored to your style of driving to deliver the most performance where you need it. In addition, rev-limiter modules can be added to the ignition to prevent engine damage.