GReddy Acura RSX Type-S

There's a single, burning question to be asked every time a new sport compact platform hits the street: Who will be the first to put a turbo on it?

In the case of the new Acura RSX, the answer is GReddy.

GReddy Performance Products turned out a comprehensive system for the RSX, complete with full exhaust, intercooler and electronic fuel management, in about three weeks and debuted the car at the SEMA show in November of 2001. Now we've tested it, and we know it works.

The exhaust and intake were the first components to go in. GReddy's Airinx AY-M intake and filter improve the initial point of induction. At the opposite end of things, GReddy designed a new application in its Evolution series of cat-back exhausts. The Evolution RSX Type-S unit features mandrel-bent, stainless-steel construction from 2.5-inch piping, a smallish muffler designed for efficient sound suppression, and a cavernous 4.5-inch tuner tip, which is embossed with a GReddy logo. GReddy's Evolution series is a mainstay in the import aftermarket community, and it generally has a good reputation for build quality, looks and, most importantly, improved flow characteristics.

In other news, a prototype exhaust manifold, also bent from stainless tubing, was fabricated to incorporate a Mitsubishi-built TD05H-18G turbocharger. The spiral unit was built to GReddy's specs and features an enlarged compressor housing, and a turbine housing that resembles the housings used on other GReddy bolt-on turbo treatments, such as for the Civic Si and Integra GS-R. An integral actuator-type wastegate is employed on the turbine side to maintain proper boost levels.

Fitment for this kit is very good, if slightly cramped, because the RSX's exhaust manifold is located at the rear of the engine bay. This necessitates the manifold, turbo and related piping be sandwiched between the engine and firewall, unlike most every other Honda engine where the header is placed in a forward location. Custom-bent plumbing takes the compressed charge and runs it through a front-mount GReddy Type 31 air-to-air intercooler core, then back to a factory throttle body and intake manifold. Interestingly, the O.E. catalytic converter is still used as the only factory exhaust component.

Since the RSX has no fuel return line, the classic fuel enrichment system relying on a high-volume pump and pressure regulator would not be used. Instead, this was an opportunity for the GReddy engineers to incorporate the company's new E-Manage piggyback fuel computer. This auxiliary brain allows its user to trim the fuel system's duty cycle under low-load conditions, improving idle, low-rpm driveability and fuel economy. Under boost, the E-Manage computer applies GReddy's pre-programmed fuel map for a shot of fuel proportional to the level of boost achieved by the turbo. Larger 440cc RC injectors squirt the juice.

We strapped the finished project to our Dynojet and found the turbo system to be alive and kicking; peak power was measured at 243 hp at 7400 rpm and 175 lb-ft. at 6100 rpm. And on test day, GReddy's car was the fastest of the group, with the exception of Flex-a-lite's vehicle. Quarter-mile e.t. between the GReddy and FAL cars were identical, but GReddy's trap speed was the fastest overall, at 108.4 mph. In the 0-60 mph contest, the GReddy car managed a very quick 5.7 seconds compared with the 5.6 second performance of the Flex-a-lite car.

On the other hand, the car's overall handling was not on par with its straight-line performance. Modifications to the car's suspension have been limited to a Tein HA coil-over suspension kit and 17x7-inch Enkei RPM2 wheels shod with Nitto NT555 rubber-which aren't exactly super sticky race rubber. On the skidpad, we measured lateral grip at only 0.86 g, which is actually worse than stock. Similarly, GReddy's RSX was also rather slow through the slalom-in fact, it was the slowest of the group, clocking a maximum speed of 68.9 mph.

There's always something to be said for a well-engineered bolt-on turbo kit, especially if it's first on the scene. At this point, GReddy's RSX kit fits this profile. The kit is still a prototype, meaning it isn't being mass-produced yet, but keep an eye on GReddy's Web site for a release date.

GReddy RSX Type-SChassis Code: DC5EngineEngine Code: K20CType: Inline four-cylinder, turbocharged and intercooled, aluminum block and headInternal Modifications: NoneExternal Modifications: Mitsubishi/GReddy TD05H-18G turbocharger with integral actuator-type wastegate, stainless steel exhaust manifold, GReddy Type 31 air-to-air intercooler, GReddy Airinx AY-M intake and filter, GReddy Evolution cat-back exhaustEngine Management Modifications: Greddy E-Manage, RC 440cc injectorsMeasured Wheel Horsepower: 243 hpMeasured Wheel Torque: 175 lb-ft.

DrivetrainLayout: Front engine, front-wheel driveDrivetrain Modifications: None

SuspensionFront: Tein coil-oversRear: Tein coil-overs

BrakesFront: StockRear: Stock

ExternalWheels: Enkei RPM 17x7Tires: Nitto NT555 225/45ZR17Body: Acura bolt-on aero kit