How to Increase Horsepower on a 4Runner

Though the Toyota 4Runner is a very good truck in stock specification, there will always be those owners who want more from them, particularly more power. Fortunately for 4Runner owners, there are multiple options available when it comes to increasing the horsepower. You can keep the costs to a minimum by purchasing a cold air intake or invest heavily with the installation of a supercharger conversion.

Things You'll Need

  • Socket set and ratchet
  • Specialty automotive tools
  • Install a larger diameter exhaust. No matter what the make and model, almost all stock exhaust systems leave something to be desired when it comes to efficient air flow. Replacing the stock 4Runner exhaust with one made from larger diameter tubing and then matched to a free-flow muffler will get spent exhaust gasses out of the motor more quickly and efficiently, which is a good thing for power. An exhaust usually requires a lift as well as special cutting and welding tools to install it properly and should be done by a shop experienced in this type of installation.

  • Replace the stock air box with a performance-oriented cold air intake (CAI). In stock form, the 4Runner’s air box restricts the flow of incoming air, which is not good for power. Swapping the air box for the CAI’s larger diameter tubing and large, cone filter will deliver more cold, dense air to the intake side of the engine for more power, better throttle response and a deeper sound from the intake. To install a CAI, first unbolt the air box from where it is bolted to the engine bay and disconnect it from the intake on the engine. Install the CAI in its place, ensuring that the filter is positioned away from the heat of the engine and where it will get lots of cold air.

  • Convert the engine to forced induction, which utilizes a compressor mounted on the intake (supercharging) or the exhaust (turbocharging). For the 4Runner, the most common method of forced induction is supercharging, since this is a technique that Toyota has used to great effect on the 4Runner. You can use the company's kit or install one of the many supercharger kits available on the aftermarket. This conversion should be done by a shop familiar with forced induction for proper results.