588 WHP Eclipse GSX Targets Single-Digit Slips - DSPORT Magazine
Eclipse ready to drag race
From bare shell to the baddest 2G Eclipse around in just four days; that was the goal facing Edward Deiure that he had neither planned nor prepared for. However, after having gone through what can only be called a series of unfortunate events, Deiure and his GSX were up for the challenge to get the running build to the Buschur Racing DSM/EVO Shootout in a little over 96 hours. Text and Photos by Richard Fong

Get What You Pay For

Deiure had purchased his ’98 Eclipse GSX as a graduation present to himself while his friends and family balked at the decision. Much to his dismay, an oil starvation condition caused a spun bearing that destroyed the original engine after only forty miles of his ownership. A second engine from a general repair shop was hastily installed and suffered a similar fate, spinning bearings after only two hundred miles of use. The third engine fared only slightly better, lasting over a year of driving and commuting before being brought to a local “garage guru” that promised an 11-second daily driver setup. Instead, a month’s worth of time and money resulted only in delivery of the news that said guru couldn’t start the car and complete the build. Nearly stock interior in the Eclipse

The interior remains stock except for the AEM wideband A/F gauges and a Sparco Steering Wheel

Lemons From Lemonade

With defeated pride, Deiure towed his Eclipse to Street Tuned Motorsports where it was ultimately determined that the third engine was blown as well. Such a turn of events would leave a sour taste in anyone’s mouth but STM tuner Emery Kapral sweetened the ordeal when he offered Deiure this solution – “How would you feel about owning the baddest 2G around?” Deiure agreed and both hashed out a game plan for the build. Side shot of the Mitsubishi Eclipse

Space Invader

STM began with modification to the body. Known for his forward facing turbo manifolds, Kapral saw a unique opportunity to incorporate the same design into the Eclipse. The front end was completely rebuilt from the apron forward. A custom tube-frame bolted to the front of the frame rails replaced the stock sheet metal and radiator support. The new structure provided mounting for the headlights, radiator, intercooler and bumper cover, freeing up the space needed for the custom forward-facing turbo manifold.

The Countdown Begins

With the front-end revisions completed, the engine bay was prepped and painted while the engine and driveline received their respective upgrades. Before the paint had dried completely, it was suddenly decided that the Buschur Racing DSM/EVO Shootout would be the perfect place to debut the car. With 96 hours and 325 miles separating the car from being at the event, STM ramped it’s efforts into overdrive. 4G63 in the Eclipse

Direct Induction

The equal-length runners of the stainless-steel manifold channel spent gasses to the PT&E 6262 turbocharger mounted just below the driver’s headlight. The inducer faces forward through a port cut in the bumper while the compressor outlet connects directly to the end tank of the STM intercooler. Once chilled, the air charge flows through custom piping to an EVO VIII throttle body and a 1G DSM intake manifold. An STM-fortified fuel system supplies E85 to a quartet of 2,150 cc/min Fuel Injector Clinic injectors that saturate the air charge as it enters the combustion chambers. Intercooler on the Eclipse

A forward facing PT&E 6262 turbocharger feeds directly into the end tank of an STM intercooler.

1G For A 2G

While the second generation DSM chassis sports a more refined appearance and improved ergonomics, it comes equipped with a 7-bolt 4G63 that suffers from crank walk when power is significantly increased. With this in mind, Deiure obtained a Buschur Racing Stage-3 shortblock as the foundation for the new powerplant. Equipped with a 6-bolt engine filled with GRP aluminum rods and JE Pistons, the stout iron block was ready for a higher-flowing cylinder head. A first-generation DSM cylinder head was equipped with a complete Supertech valvetrain, Kelford 272-degree camshafts and AEM Tru Time adjustable cam gears. Once mated to the block by way of ARP head studs, the new longblock was ready to boast about some climactic power numbers. Cam gears on the 4G63

6 vs. 7 Bolts: Which Is Better?

Up until half way through the 1992 model year, all DSM chassis (Eclipse, Laser and Talon) came equipped with a 6-bolt 4G63 engine (crankshaft has a 6-bolt hub to mate to the flywheel.) From the latter half of 1992 and on, all DSM chassis (including the 2G Eclipse) came factory equipped with a 4G63 engine featuring a 7-bolt crankshaft. The 6-bolt crankshaft featured wider bearing journals and subsequently bigger rods than those of the 7-bolt crank. This turned out to be a downgrade, as the reduced weight of the 7- bolt crank permitted faster revving but was prone to crank walk at horsepower levels beyond 350. Buschur Racing only uses 6-bolt engines for its BR race engine program.

Dyno sheet for the EclipseRefined On Rollers

With the hardware in place, it was time to tune up the software. The stock ECU got the boot in favor of a plug-and-play AEM engine management system to regulate fuel delivery and ignition timing. With boost held steady at 35psi thanks to a Hallman Pro manual boost controller, Kapral dialed in the AEM unit. Strapped to the rollers of a Mustang AWD dynamometer, the Eclipse put down 588 horsepower and 482 lb-ft torque to the wheels. Compared to a typical second-generation baseline pull of 165 horsepower, this Eclipse GSX produced 256-percent more peak power.

On Track and On Time

Some four days after the start of the build, Deiure’s Eclipse finally made the trek out to Norwalk Raceway in Ohio for the DSM/EVO Shootout. Not content with the original goal of simply debuting the build, Deiure took the opportunity to shake down the car on the track as well. “Emery and the STM really put it into overdrive, finishing the car on time. When it fired up the night before we left, I don’t think I’ve ever had a bigger smile on my face,” Deiure remarks. “I tried to run the car on the last day of the shootout, but I wasn’t able to get a clean pass. My new goal is to run a 9- second quarter-mile with this setup.” With plans for an improved fuel system, a lighter chassis and more power to the ground, it’s only a matter of time before this 2G Eclipse reaches this next goal. Now, time is all Deiure has. Eclipse at the track

2016 Update



Year / Make / Model: 1998 Mitsubishi Eclipse GSX
Chassis Code: D33A
Launch RPM: 6,500 RPM
Shift RPM: 7,500 RPM
Redline RPM: 8,000 RPM
Peak Boost: 35psi
Fuel: E85
Engine Code: 4G63
Displacement (cc): 2,021cc
Bore & Stroke (mm): 85.5mm x 88mm
Peak Horsepower (@ RPM): 588 whp @ 7,000 RPM
Peak Torque (@ RPM): 482 lb-ft @ 5,800 RPM
Dyno Type: Mustang AWD Dynamometer
Engine Builder: Buschur Racing
Block Modifications: Buschur Racing Stage 3 Race Engine, 6 Bolt
Machine Work: Buschur Racing
Pistons/Compression Ratio: JE Pistons, 10.0:1 Compression
Connecting Rods / Crank: GRP Aluminum Connecting Rods
Camshafts: Kelford 272-degree Camshafts
Valves / Springs / Retainers: Supertech Valves, Springs, Titanium Retainers
Cam Gears: AEM Tru Time Cam Gears
Cylinder Head Mods: 1G DSM Cylinder Head
Head/Main Studs: ARP Main and Head Studs
Intake Manifold: 1G DSM Manifold
Throttle Body: EVO VIII Throttle Body
Fuel Injectors: 2,150 cc/min Fuel Injector Clinic Injectors (x4)
Fuel Delivery System: Walbro 400-lph In-tank Pump
Fuelab Fuel Pressure Regulator
Magnus Fuel Rail
STM Feed & Return Lines
Engine Management System: AEM EMS
Engine Management Tuner: Emery Kapral
Boost Controller: Hallman Pro Manual Boost Control
Ignition: NGK Plug Wires
Spark Plugs: NGK Plugs
Exhaust Manifold: STM Custom Forward-facing Manifold
Exhaust System: STM Custom Downpipe and Exhaust
Wastegate: TiAL Sport 44mm Wastegate
Blow-Off Valve: TiAL Sport 50mm Blow-off Valve
Intercooler: STM Custom Front-mount Intercooler
Cooling System: Koyo Radiator
Flexalite Electric Fan
STM Coolant Overflow and Lines
Performance Electronics: AEM Digital Boost and Oil Pressure Gauges
Turbocharger: Precision Turbo & Engine 6262
Frame: T3
Compressor Wheel Specs: 82mm Major, 62mm Inducer
Turbine Wheel Specs: 72mm Major, 62mm Exducer
Turbine Housing: 82 A/R, V-band Outlet
Springs, F&R (Make & Rate): Tokico Lowering Springs
Clutch / Flywheel: ACT Twin-plate Clutch
Wheels (Make, Size & Offset): Rota Slipstream 15×7-inch +40 (F&R)
Tires (Make & Size): Hoosier Quick Time Pro Slicks
Brake Lines: STM Stainless-steel Braided Lines
Etc: STM ABS Delete Kit
Steering Wheel / Quick Release: Sparco Steering Wheel
Gauges: AEM Wideband A/F Gauge
Hood: VIS Extreme GT Carbon-fiber Hood
Custom Body Work: STM Custom Removable Tube Front End

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