IAG Big Bore 76mm Throttle Body w/ Electronics & Adapter Package (For Use With Process West Intake Manifolds) – Silver Adapter Plate – 2004-2021 Subaru STI / 2006-2007 WRX / 2004-2008 Forester XT

IAG Big Bore 76mm Throttle Body w/ Electronics and Adapter Package — Silver Adapter — 2004-2021 STI / 2006-2007 WRX / 2004-2008 Forester XT

Upgrade Your Throttle Body for 600+ HP Applications
Subaru owners pushing past 600 horsepower can find the OEM throttle body becomes a restriction — it is not large enough to flow enough air for the largest turbocharger setups. IAG’s Big Bore 76mm Throttle Body package includes a 76mm bore throttle body (silver finish only), an IAG CNC-machined 6061 aluminum adapter plate in Silver anodized finish, and all required hardware. The 76mm bore provides approximately 25% more flow than the OEM throttle body, eliminating the OEM restriction without compromising drivability. Compatible with Process West intake manifolds.

DETAILS

• Adapter plate color: Silver anodized finish
• Throttle body: 76mm bore, silver finish (same throttle body included in both color variants)
• Approximately 25% more airflow than OEM throttle body
• CNC-machined 6061 aluminum adapter plate with O-ring sealing surface
• Uses OEM electronic throttle body connector — no wiring modifications required
• Designed for use with Process West intake manifolds
• MAP sensor relocation may be required
• Package includes: (1) 76mm throttle body, (1) IAG aluminum adapter plate, (4) M6x50mm low profile socket head cap screws, (4) M6x20mm low profile socket head cap screws, (4) small O-rings, (2) large adapter plate O-rings
• Fits: 2004-2021 STI / 2006-2007 WRX / 2004-2008 Forester XT

Why the OEM Throttle Body Becomes a Restriction
The OEM Subaru throttle body is sized for factory power levels. At 600+ horsepower — particularly with larger turbochargers flowing high volumes of air — the OEM bore becomes a flow restriction that limits peak power output. Some aftermarket solutions introduce drivability problems like sticking and poor idle quality. IAG’s adapter approach preserves the OEM throttle body electronics and connector while providing a significantly larger bore.

Simple Installation
Installation involves removing the OEM throttle body and installing the IAG adapter plate and 76mm throttle body in its place. The OEM connector plugs directly into the new throttle body — no wiring changes are required. MAP sensor relocation may be necessary depending on the intake manifold configuration.

Process West Manifold Compatibility
This package is designed for use with Process West intake manifolds. Verify intake manifold compatibility before ordering.

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 Big Bore throttle body is the right upgrade when your STI or high-power WRX is pushing past 600 horsepower and you need more airflow capacity at the throttle body. The O-ring sealed adapter plate and OEM connector compatibility make it a clean, properly engineered solution. Available with a Silver adapter plate to match your engine bay.

Fitment