Eclipse Tech

It may not have the hardcore performance following of the first- and second-generation cars, but the third-generation V6 Eclipse is still gathering its fair share of aftermarket support. We decided to test the waters and see what the V6 would do with a few bolt-ons.

To increase the engine performance of our 3.0-liter, V6-powered test car, we called NOPI, which is one of the largest suppliers of cosmetic and performance products for the 3G Eclipse. NOPI sent us a GReddy Evolution cat-back exhaust, which retails for about $500, features a polished stainless-steel muffler, aluminized cat-back tubing (60-70mm diameter) and a 115mm single exhaust tip. Installation is straightforward, because the exhaust hangs firmly from the stock brackets. You'll need nothing more than common hand tools and a few hours of time, although a lift makes fitment a lot easier than jack stands.

Like any power test, we enlisted our Dynojet chassis dyno and performed several baseline dyno runs before moving on to installation.

Dyno pulls in stock trim revealed 165 hp at 5500 rpm and 178 lb-ft of torque at 4300 rpm. With the GReddy Evolution exhaust installed, we saw an immediate gain of 7.5 hp at 6180 rpm and an increase of 6.4 lb-ft of torque also at 6180 rpm. Throttle response improved on the street as well.

The GReddy exhaust serves up a deep bass note and resonates all through the gears, thanks to the 24-valve V6.

Next, we bolted on AEM's 50-state-legal, cold-air intake system. This version sports an improved air horn design for increased airflow and uses a new four-layer cotton gauze element for better particle filtration. The body of the AEM filter is constructed of urethane, which is lighter and stronger than the previous version's plastisol housing.

AEM's one-piece cold-air intake relocates the filter outside of the engine bay, down at wheel well level, for a cooler intake charge and comes complete with soft mounts for a sano-looking installation. It can also be outfitted with the AEM air bypass valve, which greatly reduces the chances of water being sucked up through the intake. If you care about aesthetics, the intake system is available in blue, red, silver and polished finish. Retail on the intake is approximately $400, depending on the finish.

On the dyno, the intake showed an improvement of 5.1 hp at 6250 rpm and 4.6 lb-ft of torque at 5640 rpm. Between the two bolt-ons, we reached peak horsepower earlier in the rpm band.

Using a Hellion OBD-II diagnostic tool, we tapped into the Eclipse ECU to measure the air intake temperatures between the stock and aftermarket systems. After a cruise through stop-and-go traffic on a pre-planned 2.5-mile route, the air intake temperature was measured 50 mph. Ambient air temperature was a moderate 75-degrees Fahrenheit.

In stock trim, the intake air was 107.6 degrees at speed. With the AEM intake, it was 111.2 degrees.

The biggest drawback with the 3G Eclipse GT is its overall 3,000-plus lb. carcass. That's a lot of weight for a sports coupe. However, as the dyno proved, there are credible aftermarket bolt-ons, which bring the weight-to-horsepower ratio back down to earth.

After disconnecting the battery, unbolt the stock intake box and disconnect all hoses to the throttle body and mass airflow sensor. You might need to use jackstands or a lift to install the filter element of the AEM intake system.	Rubber adapters for the stock mass airflow sensor and throttle body need to be installed for proper fitment of the AEM primary and secondary piping.	Next, the AEM primary intake pipe and secondary pipe can be installed as shown above.
	We decided to use the cold air type secondary pipe that snakes down to wheel well level for a cooler air charge. It bolts directly to the stock brackets from the stock box.	For photo purposes only, we show how the new AEM filter is mounted to the secondary down pipe. However, the filter is typically installed after the secondary pipe is already bolted onto the mass airflow sensor.
Reconnect all stock emission hoses to the primary AEM pipe.	The GReddy exhaust bolts directly to the third-gen Eclipse. By installing it, we picked up a 5 hp gain at the wheels.