Honda/Acura K-Series Twin Scroll Turbo Manifold
Full-Race has spent years working with Turbo VTEC engines – one thing weve clearly learned is that these engines love to breathe through properly executed twinscroll turbo setups! Twinscroll systems seperate interfering exhaust pulses, allowing for faster spool while eliminating high pressure reversion. We designed the K-series twinscroll to take full advantage of this on all size turbchargers. Whether fitting a 3″ or 4″ inlet street turbo all the way up to a massive 6″ compressor inlet drag turbo – carrying torque throughout the entire powerband, not just ‘peak power’ — translates into a faster car. This broad increase in area-under-the-curve produces an exhilirating experience for a built street/road race car or a high-boost drag race application (same manifold & WG setup, just varying turbo size). We believe the K-series twinscroll to be the ultimate high power turbo manifold for the K-series RSX and EP Civic or swapped EG / EK / DC.
Ideal for demanding applications which require huge power output without sacrificing spool or response, this turbo manifold is engineered to break horsepower and ET records. It represents the state-of-the-art in high power turbocharged K-Series performance.
K-Series Twin Scroll Turbo Manifold Dual 38
Optional 2000 Degree Titanium Coating:
- (2) 44mm TiAl wastegates are recommended for high boost
- Available without wastegate flanges for BorgWarner EFR internal-WG turbos
- Can fit up to 6″ inlet GT4708R or BorgWarner 82mm S400SX
- this manifold can support power levels from an ultra responsive 400whp to an 1100+whp drag car.
Key Design Features:
- fabricated merge collector creates a turbulent free area for the exhaust gasses to enter the turbine housing, in even pulses and high velocities.
- Robotic TIG welding for ultimate strength and longevity.
- Flange surfaces machined flat ensuring a perfect seal.
- 1 Year Warranty
- Made In The USA
6″ Compressor inlet with 4″ outlet — GTX47 92-95 EG Civic:
This video shows Ryan Chin’s K Swapped EK Civic with Borg Warner S400SX 67MM FMW, using E85 fuel”
“The car made 888 on 30 psi and on 38 it made 958 on 38 psi falling to 36 psi”
Twin Scroll turbo system design addresses many of the shortcomings of single scroll turbo systems by separating those cylinders whose exhaust gas pulses interfere with each other. Similar in concept to pairing cylinders on race headers for N/A engines, twin scroll design pairs cylinders to one side of the turbine inlet so that the kinetic energy from the exhaust gases is recovered more efficiently by the turbine. For example, if a four-cylinder engine’s firing sequence is 1-3-4-2, cylinder 1 is ending its expansion stroke and opening its exhaust valves while cylinder 2 still has its exhaust valves open (while in its overlap period, where both the intake and exhaust valves are partially open at the same time). In a single scroll AKA undivided manifold, the exhaust gas pressure pulse from cylinder 1 is therefore going to interfere with cylinder 2’s ability to expel its exhaust gases, rather than delivering it undisturbed to the turbo’s turbine the way a twin scroll system allows.
The result of the superior scavenging effect from a twin scroll design is better pressure distribution in the exhaust ports and more efficient delivery of exhaust gas energy to the turbocharger’s turbine. This in turn allows greater valve overlap, resulting in an improved quality and quantity of the air charge entering each cylinder. In fact, with more valve overlap, the scavenging effect of the exhaust flow can literally draw more air in on the intake side while drawing out the last of the low-pressure exhaust gases, helping pack each cylinder with a denser and purer air charge. As we all know, a denser and purer air charge means stronger combustion and more power… but the benefits of twin scroll design don’t end there. With its greater volumetric efficiency and stronger scavenging effect, higher ignition delay can be used, which helps keep peak combustion temperature in the cylinders down. Since cooler cylinder temperatures and lower exhaust gas temperatures allows for a leaner air/fuel ratio, twin scroll turbo design has been shown to increase turbine efficiency by 7-8 percent (faster spool, quicker response) and result in fuel efficiency improvements as high as 5 percent. It is wise to size the turbine housing A/R larger than the single scroll turbine A/R typically used!