If you haven't figured it out yet, power is evil. Once you get a taste of it, you always end up wanting more. After we performed the first battery of performance upgrades on our EVO VIII, we were hooked. We pushed the output of the Evolution by 44.4 hp, peaking at 292.4 with four bolt-on upgrades. Impressively, the increased output was done at the stock boost pressure. By using higher flowing performance parts and fine-tuning the fuel and ignition maps via AEM's EMS, we increased the Mitsubishi's output from the stock 248.0 to 292.4 hp.
To ensure the car was still up to spec, we re-baselined the Evolution on XS Engineering's four-wheel-drive DTS chassis dyno after a couple of heavy right-foot actions. It baselined at 291.0 hp-pretty much consistent with the previous session. The 1.4-hp decrease could have resulted from a change in weather conditions or from strapping the vehicle on the dyno. It's always important to perform a new baseline to kind of reset the clock. This ensures the parts previously installed are still making power and provides a new "ground zero" for future upgrades.
For this round we opted to further improve the exhaust flow characteristics by adding a tubular, stainless-steel turbo manifold from DC Sports. The manifold we tested was a prototype piece, but by the time this issue hits the presses, it should be available to the masses.
The factory turbocharger features a twin-scroll design similar to those used on the 4G63 Eclipse GSX and GS-T turbos. The factory Evolution turbocharger has two inlet ports in the turbine housing. The twin-scroll turbocharger only works with a turbo manifold designed for this configuration. The factory cast manifold links the number one and four exhaust ports and the two and three exhaust ports together. Each pair converges to feed each side on the turbocharger inlet simultaneously based on the engine's firing order.
Often the factory components are designed with cost in mind. In doing so, the stock turbo manifold isn't very free-flowing and has several harsh angles restricting flow. DC Sport's tubular, stainless-steel turbo manifold follows the same general characteristics of the stock manifold but is designed for better flow.
Unlike the cast manifold, the DC Sports piece utilizes smooth radius stainless-steel tubing to expedite exhaust flow from the exhaust ports of the cylinder head into the turbocharger. Like the stock manifold, the DC Sports manifold links cylinders two and three, and one and four. The manifold features stainless flanges that are CNC-machined and the entire manifold is TIG-welded. The DC Sports piece also keeps the turbocharger in the exact same location as the stock manifold, so there's no need to change any components you're currently using.