In house R&D and Manufacturing since 2003

Build Now, Pay Later

The offer is valid for all orders within the USA. For other countries, the cost will be automatically calculated on checkout.

Free Shipping Over $199

Call Our Experts: +1 (602) 437-2101

Honda / Acura K-Series Twin Scroll EFR T4 IWG Turbo Manifold


Honda/Acura K-Series Twin Scroll IWG EFR Turbo Manifold

This product is in stock and ready to ship!
In stock

Honda/Acura K-Series Twin Scroll IWG EFR Turbo Manifold

Honda/Acura K-Series Twin Scroll IWG EFR Turbo Manifold

Full-Race’s K-series Twinscroll EFR T4 IWG turbo manifold evolved as an option for those looking to have fast spooling, reliable HP without the complexity and weight of dual external wastegates, BOV, and boost controllers. Ideal for road racing and street/strip setups, this proven design will spool faster, last longer, and produce more reliable power across the entire RPM range than any other manifold on the market. EFR internal wastegate requires ‘C-housing’ 0.92 A/R EFR turbochargers and maximizes firewall and brake master cylinder clearance.
Twinscroll systems seperate exhaust pulses, allowing for faster spool while eliminating high pressure reversion. We designed the K-series twinscroll to take full advantage of this and spool medium to large turbos faster than any other design on the market – carrying torque throughout the entire powerband. This produces an exhilirating experience for a built street/road race car or a high-boost drag race application. We believe the K-series twinscroll to be the ultimate high power turbo manifold for the K-series RSX and EP Civic or swapped EF / EG / EK / DC.


  • Fits almost every Honda K series chassis combination from 1988 to 2005: K-swapped CRX’s, EF/EG/EK/EM1 Civics, DC Integras, EP3 civics and RSX’s with K20 and K24 engines
  • RHD and LHD compatible
  • twin scroll IWG spools earliest with huge midrange torque, however high boost on a vtec engine can have a slight top end drop compared to T3 single scroll

Honda/Acura K-Series Twin Scroll IWG EFR Features:

  • Based around low angle 4-2-1 merge collector for efficient flow into the turbocharger and fastest spool possible
  • Robotic TIG welding ensures superior strength and long service life
  • CAD designed
  • 100% Handmade in the USA from high grade thickwall stainless steel
  • Specifically designed for BorgWarner EFR T4 Twin Scroll 0.92 A/R fitment
  • Utilizes an Internal Wastegate Configuration
  • Sealing surfaces machined flat ensuring a leak free seal

Install Photos:

Dyno Graph:

93 octane dyno


Race Gas dyno









Full Race

Write A Review


Full-Race Motorsports is the most
trusted name in turbocharging.

Wholesale Inquiries