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 with an adapter to use WRX - style drive - by - cable throttle body. 08 - 14 WRX with EJ25 needs an STI - style drive - by - wire throttle body, and 08 - 21 STI may require mild clearancing of the A/C compressor line.Features: Stay ahead of your rivals with the AMS Performance Subaru EJ25 Intake Manifold! It's designed for high - performance and big - HP custom setups. After lots of testing, it outperforms others on the market. It has a texture red powder coating, standard rotation configuration, 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 allows matching to larger hand - ported or CNC ones. 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 optimizing power output by sculpting the interior geometry. Using Solidworks© and CFD software, it has a large 4.5L plenum for top - end power, CNC - machined bellhorns for a broad power curve, and optimized runners for less turbulence and more power.Unmatched Power Gains and Excellent Response: This intake manifold offers not only top - end power but also a wide power - band. It can greatly improve lap times and give you the confidence to beat opponents on the road or drag strip.Product Notes: Due to various 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 proper modifications. The intake manifold is flanged for 04 - 21 STI drive - by - wire throttle bodies, but cable throttle bodies can be used with custom fitting. Standard intercooler piping needs mild custom fabrication. 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 to mount the factory upper coolant reservoir. The bottom of the center plenum has ports for vacuum accessories, and 2008 - 2021 STI may need mild clearancing of the A/C compressor line.
Using this AMS intake manifold is a great way to boost your Subaru's performance. First, make sure it fits your vehicle according to the fitment information. If you have a 2002 - 2005 WRX with EJ20, you'll need an adapter to use the WRX - style drive - by - cable throttle body. For 2008 - 2014 WRX with EJ25, use an STI - style drive - by - wire throttle body. When installing, be aware that 2008 - 2021 STI may require you to do a bit of clearancing on the A/C compressor line. Also, due to the many rotated turbo kits on the market, there's a chance of interference with the cylinder 3 intake runner, so check the fit carefully. Some port matching might be necessary if you're using CNC or hand - ported cylinder heads. When it comes to throttle bodies, you can use larger ones with proper modifications and maybe an adapter flange. The intake manifold is set up for 2004 - 2021 STI drive - by - wire throttle bodies, but you can use cable throttle bodies with custom fitting. The standard intercooler piping will need a bit of custom work because of the throttle body's placement. As for injectors, use the common Subaru aftermarket top - feed injector size, and we recommend Injector Dynamics brand injectors. Don't try to use standard Subaru style injectors. This intake manifold isn't compatible with side - feed to top - feed conversion rails and requires aftermarket rails and lines. It won't work with top - mount intercoolers, and you'll need to make custom bracketry to mount the factory upper coolant reservoir. For maintenance, keep an eye on the vacuum accessories ports at the bottom of the center plenum. Regularly check for any signs of wear or damage, and if you notice any issues, get them fixed right away. With proper use and care, this intake manifold will keep your Subaru running at its best.
