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 little clearance for the A/C compressor line.Features: Get ahead of the competition with the AMS Performance Subaru EJ25 Intake Manifold! It's designed for high - performance and custom big - HP setups. After lots of testing, it makes more power than other manifolds on the market. It's uncoated, with a standard rotation configuration. It has a 4.5 - liter plenum volume, 13 - inch equal - length intake runners, 2.5 - inch intake runner diameter, and a 3.8 - inch bellhorn OD. The increased port size at cylinder heads can match larger hand - ported or CNC parts. The throttle body opening 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. It's cast, which makes it stronger and allows for better power output by optimizing the interior geometry. Using Solidworks© and CFD software, it has a large 4.5L plenum for top - end power. The CNC - machined bellhorns provide a broad power curve and high - RPM horsepower.Unmatched Power Gains and Excellent Response: This manifold offers more than just top - end power. It gives a wide power - band and a big power boost when in boost, improving lap times and giving you an edge over opponents.Product Notes: Due to the variety of rotated turbo kits, fitment with every brand can't be guaranteed. Some port matching may be needed with CNC or hand - ported cylinder heads. Larger throttle bodies can be used with modifications. The intake manifold is flanged for 04 - 21 STI drive - by - wire throttle bodies, but cable throttle bodies can work with custom parts. Standard intercooler piping may need some custom work. It uses a common Subaru aftermarket top - feed injector size, and standard Subaru style injectors can't be used. It's not compatible with side - feed to top - feed conversion rails, requires aftermarket rails and lines, and isn't compatible with top - mount intercoolers. It also needs custom bracketry for the factory upper coolant reservoir. The center plenum has ports for vacuum accessories, and 2008 - 2021 STI may need A/C compressor line clearance.
Using the AMS intake manifold is a great way to boost your Subaru WRX or STI's performance. First, make sure to check the fitment details based on your car's year and engine type. If you have a 2002 - 2005 WRX with EJ20, you'll need an adapter for the throttle body. For 2008 - 2014 WRX with EJ25, use an STI - style drive - by - wire throttle body. When installing, be aware that the 2008 - 2021 STI might need some clearance for the A/C compressor line. Also, because of the many different rotated turbo kits out there, there's a chance of interference with the cylinder 3 intake runner, so double - check. If you're using CNC or hand - ported cylinder heads, you may need to do some port matching. You can use larger throttle bodies, but they'll require proper modifications and maybe adapter flanges. The intake manifold uses a common Subaru aftermarket top - feed injector size, so don't try to use standard Subaru style injectors. And remember, it needs aftermarket rails and lines, not the stock ones. As for maintenance, keep an eye on the throttle body and the intake runners. Make sure there's no dirt or debris buildup. If you notice any power loss or strange noises, it might be time to inspect the manifold. Also, check the vacuum ports regularly to ensure they're working properly. That's it! With proper use and maintenance, this intake manifold will keep your Subaru running great.
