Throttle body spacers are an easy-to-install and inexpensive Subaru Legacy engine modification that have gained popularity in recent years with tuning enthusiasts because of their helix whirlwind effect in the intake stream. Companies like Steeda have claimed gains of 2-4 horsepower with only a throttle body spacer installed, and some companies have reported up to a 25 ft. lb. gain in torque!

Throttle body spacers are an old trick that harkens back to the days of carburetors, and are designed to increase torque and create smoother throttle response at lower RPMs, as well as increase fuel economy. Much like intake manifold spacers, Subaru Legacy throttle body spacers increase intake plenum volume, but they differ in that they have grooves cut in the bores which are said to swirl the intake air and create more turbulence, resulting in better air/fuel atomization. We've found that the effects of a Subaru Legacy throttle body spacer will vary with your driving habits and your particular model of vehicle.

Q: What are throttle body spacers? Why buy them?
A: Throttle body spacers mount between your throttle body and intake manifold and serve to increase airflow by boosting intake velocity and creating turbulence which improves combustion. The net result is a rise in power, crisper throttle response and better overall engine efficiency. This is a modification that has virtually no downside. Normally made of aluminum or high-strength plastic and available in a range of thicknesses for precise engine tuning, throttle body spacers are inexpensive, simple to install, can provide increased power and mpg, and have a stealth look that is hard to detect even by a trained eye. When it comes to bang for the buck power adders, throttle body spacers rank high on our list. Do not overlook this simple upgrade.