Fitment Information: This intake manifold fits 2002 - 2014 Subaru WRX and 2004 - 2021 Subaru STI. Note that it will fit 02 - 05 WRX with EJ20 only when using an adapter for the WRX - style drive - by - cable throttle body. 08 - 14 WRX with EJ25 needs an STI - style drive - by - wire throttle body. 08 - 21 STI may need a bit of clearance for the A/C compressor line. Features: Stay ahead of the competition with the AMS Performance Subaru EJ25 Intake Manifold! Designed for high - performance and big - HP custom setups, it outperforms others on the market. After extensive testing, it generates more power than available alternatives. It has an uncoated finish, a standard rotation configuration, a 4.5 - liter plenum volume, 13 - inch equal - length intake runners, a 2.5 - inch intake runner diameter, a 3.8 - inch bellhorn OD, increased port size at cylinder heads for better matching, and a throttle body opening that can accept larger throttle bodies up to 2.625 inches (or 70mm with mild porting). Engineered to Be the Best: AMS used years of engineering experience to design this intake manifold. Designed, prototyped, and tested in - house, it's cast for strength and optimized power output. With a 4.5L plenum size and CNC - machined bellhorns, it offers a broad power curve and high - RPM horsepower. The large runners and matched cylinder port angles minimize turbulence and maximize power. Unmatched Power Gains and Excellent Response: This manifold provides not only top - end power but also a wide power - band. It gives a huge power boost during boost, improving lap times on the track and giving you the edge on the street or drag strip. Product Notes: Due to various rotated turbo kits, fitment with every brand can't be guaranteed. Some port matching might be needed with CNC or hand - ported cylinder heads. Larger throttle bodies can be used with proper mods and may need adapter flanges. The intake manifold is flanged for 04 - 21 STI drive - by - wire throttle bodies, but cable throttle bodies can be used with custom parts. Standard intercooler piping may need mild custom fabrication. It uses a common Subaru aftermarket top - feed injector size. Standard Subaru style injectors can't be used, and it's not compatible with side - feed to top - feed conversion rails or top - mount intercoolers. It also requires aftermarket rails and lines and isn't directly compatible with the factory upper coolant reservoir (custom bracketry needed). The center plenum bottom has ports for vacuum accessories, and 2008 - 2021 STI may need A/C compressor line clearance.
Using this AMS intake manifold is a great way to boost your Subaru's performance. First, make sure to check the fitment details for your specific Subaru model year and engine type. For installation, follow the general guidelines for intake manifold installation, but be aware of the special requirements like using the right throttle body and possible clearancing. When using it with a rotated turbo kit, double - check for any interference with the cylinder 3 intake runner. Maintenance is straightforward. Regularly inspect the intake manifold for any signs of wear, damage, or leaks. Keep it clean from dirt and debris. If you need to replace any parts like the throttle body or injectors, make sure to use the recommended sizes and brands. Remember, this manifold is designed for high - performance setups, so give it the care it deserves to keep your Subaru running at its best.
