AMS EJ25 Intake Manifold
AMS EJ25 Intake Manifold
AMS EJ25 Intake Manifold
Click to zoom in

Have Questions?

  • Genuine Parts

    Guaranteed Authentic

  • Modification Specialists

    Call for assistance

  • Mod Now, Pay Later

    Financing Available

  • Save On Delivery

    Free shipping on most orders over $199

AMS EJ25 Intake Manifold

2 sold in last 8 hours
Snap Logo Lease for as low as $/week Learn More

customers are viewing this product

Here, you are looking at the AMS Performance EJ25 Intake Manifold. This manifold has been designed for those looking for the right intake manifold to accommodate big horsepower setups. AMS utilized computational fluid dynamics software and the result is a larger plenum size of 4.5L for more top-end power, along with CNC machined bellhorns which act as internal velocity stacks which will allow for a broader power curve and high RPM horsepower capabilities. 


  • 4.5-liter plenum volume
  • 13" Equal length intake runners measured from the face of bellhorn to end of the runner
  • 2.5" (63.5mm) intake runner diameter
  • Bellhorn OD 3.8" (96.7mm)
  • TGV housing replaced with long runner design
  • Increased port size at cylinder heads allow matching to larger hand ported or CNC ported cylinder heads
  • Throttle body opening accepts larger throttle bodies up to 2.625" (66,675mm) or 70mm with mild porting
  • This version intake manifold is available with a standard orientation
  • Bottom of the center plenum features 4-1/8" and 1-1/4" NPT spots for vacuum accessories
  • Uncoated, textured ted, gold, bronze, black, and blue colors available


  • Some port matching of the manifold may be required when used in conjunction with CNC or hand ported cylinder heads
  • Larger throttle bodies can be used with proper modifications (up to 70mm with minor porting, larger throttle bodies may also require adapter flanges)
  • The intake manifold is flanged for 04+ STI drive by wire throttle bodies, other models (such as 08-14 WRX) require a change to the STI style throttle body
  • Cable throttle bodies (such as 02-05 WRX) can be used with custom fitting and flange adapter
  • Standard configuration intercooler piping will need mild custom fabrication due to placement of throttle body
  • Designed to use common Subaru AFTERMARKET top feed injector size (48mm overall length / 11mm inlet-standard Subaru rail size / 14mm outlet)
  • Not compatible with OEM subaru injectors
  • Not compatible with stock fuel rails or lines, requires aftermarket top feed rails and lines
  • Not compatible with top mount intercoolers
  • Not compatible with hard pipe stock location turbo inlets, requires silicone inlet
  • Not directly compatible with mounting the factory upper coolant reservoir

    *Pictures used for marketing purposes only, actual products may vary 

  • Read More
    Read Less
    Returns Policy

    Returns may be accepted within 14 days of purchase pending Return Merchandise Authorization (RMA). No returns or cancellations on special order items. All returns will be charged a 20% restocking fee, no exceptions.

    To be eligible for a return, your item must be unused and in the same condition that you received it. It must also be in the original packaging. Item must be able to be resold as new. Several types of goods are exempt from being returned. Hazardous materials, fluids, greases, chemicals, and clothing are not able to return.

    Free shipping is available within the lower 48 states for most orders totaling $199 or more. A free shipping option will be available during checkout. This offer is for delivery address in the continental United States and excludes shipments going to Alaska, Hawaii, Military Boxes, and items that require freight shipping.

    Processing Time
    Patterson Performance stocks a large quantity of items at any given time. Some items may require drop shipping from one of our various distributors. In stock items will ship within 1-2 business days. If you're needing your product quickly, please contact us to verify product availability before placing your order. Orders requiring additional verification (security concerns, incorrect information, etc.) may need additional processing time. Estimated shipping dates are not guaranteed and are subject to change based on inventory levels and manufacturer lead times. Backordered items are shipped immediately once available.

    Items ship daily, If the item you ordered is not in stock, a member of our team will contact you via email / phone.

    Patterson Performance will only ship to an address that varies from your billing address if payment is made via Paypal or a financing partner.

    Patterson Performance ships from multiple warehouses throughout the United States, and sometimes from manufacturers overseas.

    You can simply contact us via email / telephone for a live inventory check

    P65 WARNING: Cancer and Reproductive Harm

    Find more information at

    Customer Reviews


    Someone recently bought a

    The cookie settings on this website are set to 'allow all cookies' to give you the very best experience. Please click Accept Cookies to continue to use the site.

    Your cart