DC Sports 4-2-1 Race Header
The next step in our build-up was to remove the existing aftermarket header to replace it with a DC Sports 4-2-1 race header (part number NHR4205). DC Sports claims that its headers are dyno tested to outperform all comparable header systems on the market. We've toured their facility, and they do indeed test everything. They also use cutting-edge manufacturing equipment including CNC mandrel benders, and non-contact digitizing scanners for accurate blueprinting. DC Sports CNC-machines its flanges; machine-grinds the flange mating surface to ensure a leak-free seal; and uses robotic welders to attach the flange to the header pipes - ensuring superior strength and perfect fitment with every header system. The company's headers are available in 100% 304-stainless steel (flanges included), and in mild steel with a proprietary temperature- and corrosion-resistant ceramic coating.
The 4-2-1 header design typically increases mid-range power. However, unlike traditional DC Sports headers that are 50-state legal and carry CARB-EO numbers, the race header is for off-road use only due to the elimination of the catalytic converter. Eliminating the catalytic converter allowed DC Sports to design the header with longer primary runners - a design that delivers in both the mid-range and the top-end. This gain in power comes with a cost: this header is not street legal. Without going off on a tangent about which header design will work the best for your ride, check out the article "Which Header is Best for my Car?" in the May 2006 issue of Turbo for an in-depth look at performance header systems.
With the DC Sports race header installed, we strapped the vehicle back down for some dyno runs. The power gains were impressive throughout the entire rpm band, showing an increase in horsepower of 2.5-8.5 and an increase in torque of 3.4-10.2 lb-ft. The largest gain over stock was 8.5 hp at 4750 rpm and 10.2 lb-ft of torque at 3250 rpm; and overall peak numbers climbed to 145.6 hp at 5500 rpm and 156.0 lb-ft of torque at 4250 rpm - a full 7 hp and 17.4 lb-ft of torque over the intake alone.
AEM Plug & Play Engine Management System
The next test in the process was to install AEM's Plug & Play Engine Management System with a built-in UEGO controller into our 240 (part number 30-1611U). AEM's EMS plugs directly into a vehicle's factory ECU harness and requires no additional wiring or hardware. It uses Windows software, and includes an integrated tuning wizard that allows users to create a base map specifically for a car's configuration - regardless of what type of injectors, sensors, coils or other changes have been made. This same software ran the retired world-record setting AEM Racing RWD Civic; and runs the current AEM Racing S2000 and 350Z - along with many other racing vehicles in drag, drift SCCA, rally, Bonneville and other race series.
Since our 240 modifications up to this point were light, we didn't expect a dramatic increase in horsepower over the factory ECU. However, since the DC Sports Race header eliminated the factory cat, we thought some tuning would maximize the power increase of these parts. Considering we only added two bolt-on mods, power gains with AEM's EMS were impressive - increasing horsepower 1.9-5.5 and torque 3.9-7.2 across the rpm range. The largest gain of 5.5 hp occurred at 4000 rpm, and we gained an additional 7.2 lb-ft of torque at 4000 rpm. Overall peak numbers jumped up to 149.6 hp at 5500 rpm and 160.9 lb-ft of torque at 4250 rpm.
Thanks to AEM's Short Ram and EMS, and DC Sports' race header, our 240 is well on its way back to glory. In upcoming issues we will install more aftermarket pieces to our drift 240 project vehicle, including some more engine and suspension modifications, culminating in a test session with one of drifting's premier racers. Stay tuned.