How Much Improvement Can You Really Expect?
As truck guys, it is a fact that we need our horsepower and torque, and no time is it more apparent than when we add big, heavy tires, weighty armor and accessories, and lifts that make our rigs less aerodynamic. Short of tearing into the engine, what can you do to increase your engine’s output and make it more efficient? There are a huge number of companies making performance-increasing bolt-on parts, so here is a general overview of the most popular power improvers.
How Bolt-on Power Works
Many people wonder if bolt-on power is just snake oil. The rationale being that if my car could really make that power, it would have come that way from the factory. Well yes, and no. Unlike aftermarket performance companies, the OEs need to serve a number of masters and the tuning of a product reflects a compromise of fuel economy, fuel octane, costs, noise levels, sound, emissions, and other factors. This leaves some performance on the table for the aftermarket to extract with the power-adding products you’ll read about here.
Performance air filters can increase horsepower and improve throttle response. Filters come in several types of media, some being dry and some being oiled. Direct replacement filters have the same shape as an OE filter, but improve flow by increasing surface area through the use of deeper and more numerous pleats. This greater surface area allows the filter to flow more freely than stock, even when dirty. Direct replacement filters are an easy way to open up your factory intake and require no modifications. Other benefits of drop-in filters are an improvement in efficiency, a small increase in horsepower (1hp-4hp), and the ability to be cleaned and reused. Generally speaking, a properly installed direct-replacement performance filter doesn’t have any real drawbacks.
Intakes are one of the most popular add-ons because they deliver the most bang for the buck and are often easy to install and relatively inexpensive to buy. An intake essentially pairs a new, high-flow intake tract with a performance air filter, which allows the engine to take in a larger volume of air.
The biggest gains are usually seen by “cold air” versions, which typically protect the air filter and draw cooler air from outside the engine compartment, providing the engine with a denser air charge. These intakes are often more expensive and are more complicated to install than a standard aftermarket intake.
Quality intakes can provide 6-20 horsepower, depending on engine size, and owners often report a small increase in fuel economy. Drawbacks of performance intakes can be an increase in noise level and, depending on the application, power that doesn’t manifest until high RPM levels. It is also important to note your aftermarket intake’s location, as it could be lower than stock or less protected, limiting water fording capability.
Some of the most popular power-enhancing products are programmers. While the main goal of a programmer is to increase power, some offer the benefit of increasing fuel economy, while others come packed full of ancillary features, such as the ability to calibrate the speedo, adjust for a re-gear, or adjust transmission shift points. Most programmers are highly engineered and considered safe upgrades.
Gas engine programmers typically achieve their gains by adjusting engine timing and requiring the user to use premium fuel, although some programmers promise gains from regular fuel. Turbodiesel and other forced induction applications can see incredible gains by adjusting the amount of boost, among other parameters. With a typical gas engine programmer, gains of 5-8 percent are realistic.
Programmer pros are increased power, the ability to maximize gains when used in conjunction from other bolt-ons, and increased efficiency. Cons can include the expense of premium fuel, power gains that are only available at wide-open throttle on some models, and the sensitivity of some diesel engines to excessive boost or power.