For 2005, significant enhancements were made to both the RSX and RSX Type-S to reset that standard to an even higher level. These enhancements were designed with three specific objectives in mind:
1. To boost the already formidable performance of the Type-S model by increasing horsepower and optimizing the 6-speed manual transmission
2. To provide more precise handling and better ride comfort for both models by optimizing the suspension, steering and braking systems
3. To highlight the aggressive, yet refined nature of the RSX with enhanced styling inside and out
For 2005, modifications to the intake, exhaust and emissions systems were made to the Type-S model's 16-valve, DOHC i-VTEC 2.0-liter four-cylinder engine to boost power to 210 horsepower at 7800 rpm (up from 200 hp at 7400 rpm on the previous model) and 143 lb-ft of torque at 7000 rpm (up from 142 lb -ft at 6000 rpm). To complement the engine performance gains, the final gear ratio of the Type-S 6-speed manual was lowered by 8.6 percent to provide quicker acceleration. Single cone carbon synchronizers replace double cone brass synchronizers on fifth and sixth gears to provide a more direct shift feel and reduce mechanical losses in the transmission.
High performance camshafts were applied on RSX Type-S models. Increases in both the intake and exhaust valve opening angles boost the rate that air moves into and exhaust moves out of the cylinder. At high engine speeds, valve lift on the intake side is increased by five degrees and on the exhaust side by 10 degrees compared to the previous model. The new camshafts increase engine breathing and help deliver enhanced top-end horsepower.
On the Type-S powerplant, a short, high-performance single-stage manifold is used to help boost high-rpm power. The diameter of the intake duct was enlarged 11 percent from 63 mm to 70 mm to increase intake flow, especially at high rpm. In addition to increasing flow, this larger intake duct creates more sport sound, the deep, throaty rumbling produced by the engine under hard acceleration.
To help the Type-S produce 210 horsepower, the exhaust system has been retuned for 2005 to increase exhaust flow. By employing a larger diameter tail pipe (70 mm compared to 60.5 mm on the previous Type-S), and by reducing the density of the ceramic substrate in the catalytic converter, exhaust flow was increased from 95 liters per second to 98 liters per second.
To complement the additional horsepower, Type-S models receive an additional engine mount damper added to the subframe to help reduce rocking and isolate powertrain NVH from the passenger compartment.
Source: Honda PR