IAG Lower Intake Plenum Silver – 2015-2021 Subaru WRX

IAG Lower Intake Plenum — Silver — 2015-2021 Subaru WRX

Replace the OEM TGV Housing and Lower Riser in One Component
The IAG Lower Intake Plenum for the 2015-2021 Subaru WRX completely replaces the OEM tumble generator valve (TGV) housings and the separate lower plastic risers of the FA20 DIT engine in one CNC-machined billet aluminum assembly. The OEM lower riser contains a diverter that restricts flow — IAG’s unit eliminates this diverter entirely, improving airflow and performance. Available in Silver anodized finish.

DETAILS

• Color: Silver anodized finish
• CNC-machined from billet aluminum
• Direct replacement for OEM TGV housings and lower plastic risers
• Eliminates the diverter in the OEM lower riser for improved flow
• No porting modifications required
• Package includes: (2) CNC-machined lower intake risers, (14) socket head bolts, (14) flat washers
• Fits: 2015-2021 Subaru WRX

What the OEM TGV Does and Why to Replace It
The OEM TGV (Tumble Generator Valve) housings on the FA20 DIT create tumble in the incoming charge for emissions compliance at low loads. At higher performance levels, the TGV and the diverter in the lower riser restrict flow and reduce performance potential. IAG’s lower intake plenum removes both restrictive elements in one billet machined assembly.

No Porting Required
Unlike ported TGV housings that require machining of the OEM casting, IAG’s billet plenum is CNC-machined to spec from the start. No additional porting work is needed — install and run.

Compatible with IAG Fuel Lines
The IAG lower intake plenum is compatible with IAG’s PTFE fuel line kits and the existing sensors and motors from the OEM TGV assembly, making installation straightforward.

Why Choose IAG Performance

IAG Performance has been building Subaru-specific engine and drivetrain components since 2001, and in that time they have become the standard by which serious Subaru builds are measured. Based in Westminster, Maryland, IAG designs, machines, and assembles their products in-house using Haas CNC equipment and their own engineering team. Their catalog spans everything from short blocks and long blocks rated to 1150 BHP all the way down to the fuel system, oiling, and drivetrain hardware that keeps modified Subarus running reliably for years. Every IAG product exists because a problem needed a better solution than what was available — and the engineering shows.

The RallySport Take

The IAG Lower Intake Plenum is one of the most meaningful bolt-on performance upgrades for the 2015-2021 WRX. Replacing the restrictive OEM TGV housing and lower riser with IAG’s billet aluminum unit is a direct flow improvement that pairs well with any other intake or turbocharger upgrade. Available in Silver to complement your engine bay.

Fitment