Power Pages: 1999 Mitsubishi Eclipse GS-T

The Car: 1999 Eclipse GS-T
Owner: Mike

Locating a stock front-wheel-drive Eclipse is about as easy as finding pistons for a rotary-- impossible. Power Pages always consist of Hondas--they're a dime a dozen--but finding a stock Eclipse is pretty much impossible. Here at Tuner, we've had one turbo Eclipse and two normally aspirated Eclipses since the start of the magazine, which tells us that's not enough.

Most of Eclipses we see are all-wheel drive, a challenge because they're impossible to run on a two-wheel-drive dyno. The gods were smiling upon us the day that Aries Dizon from Dynamic Autosports called to inform us about a stock front-wheel-drive GS-T they were about to perform surgery on.

THE FACTS
Engine Tested: 4G63
Application: 1990-'99 Mitsubishi Eclipse, 1991-92 Galant VR-4
Common Swaps: None
Replacements: None

The Engine
The 4G63 engine housed in the '99 Eclipse turbo is the same engine that motivates Sean Glazar and Brent Rau down the quarter mile in nine seconds. The potential in this 2.0-liter turbocharged engine is limitless and, considering the stock mill is factory rated at 210 ponies and 214 lb-ft of torque, already gives it an edge over the competition. As far as aftermarket support on this beast, you name it and you can bet your ass a company will have it.

Performance Components
For these "Power Pages," we called upon some of best companies to get a taste of the potential in a GS-T. We started with the basics; an aftermarket air filter, upgraded exhaust system and turbo downpipe.

Our intake system is made by Injen Technology. This showcase piece comes in a polished aluminum and is also offered with and without a blow-off valve inlet flange. Since most aftermarket blow-off valves vent into the atmosphere rather than routing back into the intake track, Injen eliminated plugging an unused hole in the intake by offering two different intakes for the two different types of blow-off valves. The filter is an open element type, complete with a cast aluminum mass air adapter.

The exhaust system is the same type used by most of the Eclipse pros. Thermal Research & Development makes a full stainless-steel, 3-in. system, complete with all hardware needed to bolt the exhaust system to the factory downpipe. The muffler is also stainless, equipped with a 4-in. polished tip. For OBD-II vehicles, the second O2 sensor bung is also available.

Buschur Racing has been in the Diamond Star tuning business since the beginning of the turbo Eclipse era. One of its hardest hitting products is a 2.5-in. downpipe that features a complete bolt-on installation. The piece is made of mild steel that bolts to the factory O2 housing and O.E. catalytic converter. Although this unit doesn't remove the OEM cat, it is still considered an off-road power adder.

Dyno Testing
Baseline testing was performed with the GT Sport ADR-50 wheels on Falken 451 tires. Our foundation is set at 165 hp at 185.0 lb-ft of torque. Considering the circumference difference, horsepower was still at a nominal level for a stock GS-T, so upgrading the looks of our Eclipse didn't affect the horsepower output much.

The Injen intake was simple to install since all the necessary brackets and connectors came complete with the unit. The mass air adapter and filter complement the engine bay in OEM fashion and the intake pipe installs just like factory. When comparing the O.E. pipe with the Injen unit, there was a very noticeable difference in restriction. The O.E. unit has a blow-off valve inlet causing restriction to the turbo. A quick pass on the dyno once it was fixed uncovered hidden ponies--11 peak horses over baseline and 10 lb-ft of torque. Wow.

Since the '99 model is OBD-II, there is a second O2 sensor located in the exhaust system. For this reason, Thermal incorporated a second bung to cater the needs of the OBD-II vehicles. The bolt-on cat-back exhaust system provided an excellent deep tone and plenty of power to back up the growl. On the rollers, 180.5 ponies and 199.1 lb-ft of torque were generated using the Thermal exhaust system.

The downpipe is by far the easiest of all the products to install; five bolts and the O.E. unit can be removed. The Buschur unit bolts in the same fashion as the O.E. piece using all the factory bolt holes. The downpipe brought out the power hidden in the turbo. Power from 3300 rpm on up was discovered, along with a peak gain of 188.1 ponies and 210 lb-ft of torque. Approximately five to 15 ponies were realized in the mid range.

Conclusion
With just a few simple bolt-ons, the Eclipse was able to break into the 180-hp range. Since we're already more than 200 lb-ft of torque from the baseline, this vehicle is just a few more installs away from laying down more torque to the wheels than the factory rating at the flywheel.