The 2G Eclipse Platform

The second-generation Mitsubishi Eclipse (1995–1999) remains a cult favorite among budget-minded performance enthusiasts. Its lightweight chassis, capable 4G63 turbo engine (in the GSX and GST trims), and extensive aftermarket support make it an ideal candidate for builds targeting 300+ horsepower. The non-turbo RS and GS models share the same body but come with the 420A engine from Chrysler, which can also be turbocharged—but the 4G63 platform is far more robust for high boost applications. For this cost breakdown, we focus on the 4G63-powered 2G Eclipse (GST/GSX), as the DSM T3 turbo kit is designed specifically for that engine layout.

Understanding the DSM T3 Turbo Kit

The DSM T3 turbo kit refers to an aftermarket turbocharging system using a T3-flanged turbocharger, commonly paired with a divided or open T3 manifold. Unlike the factory TD05H-16G or small 14B, a T3 frame allows a wider range of compressor and turbine options, enabling higher airflow and boost levels. Kits typically include the cast iron or tubular exhaust manifold, a T3 turbocharger (often a 50-trim or 57-trim), an external wastegate, an intercooler, piping, and oil/water lines. A budget-friendly kit priced around $1,200 is a complete “stage 2” package that can support 300–400 wheel horsepower with proper supporting mods. However, the quality and longevity of components vary—cheaper kits may use generic Chinese turbo internals and thin-core intercoolers, which can limit reliability at the upper end of the power target.

Key Components in the $1,200 Kit

  • Turbocharger: Typically a T3 50-trim or similar with a .48 or .63 A/R turbine housing. Good for 300–400 hp.
  • Manifold: Mild steel or cast iron T3 flange. Some kits include a divided manifold for twin-scroll setups, but most are single-entry.
  • Wastegate: 38mm external wastegate (usually a Tial-style copy). Essential for boost control.
  • Intercooler: Bar-and-plate core, often 24x12x3 inches. Barely adequate for 300 hp; larger cores recommended for 350+.
  • Piping and Couplers: Aluminum pipes with silicone couplers and T-bolt clamps. Quality varies—thin wall can collapse under high boost.
  • Oil/Water Lines: Braided stainless steel lines with fittings. Check compatibility with your engine block.

Cost Breakdown of the DSM T3 Turbo Kit

Below is a realistic line-item breakdown of a typical $1,200 DSM T3 kit. Prices are estimates based on online retailers (e.g., eBay, STM Tuned, FP Turbo).

  • Turbocharger (T3 50-trim) – $600
  • Exhaust Manifold (tubular or cast) – $200
  • External Wastegate (38mm) – $150
  • Intercooler (bar-and-plate) – $200
  • Intercooler Piping Kit – $150
  • Oil/Water Line Kit – $50
  • Hardware and gaskets – $50
  • Total – $1,200

Note: Many budget kits group these items together; standalone parts from reputable brands (e.g., Garrett turbo, Precision intercooler) can easily triple the cost. The $1,200 price point usually implies generic components that will work but may not hold up to relentless track use. For a street car targeting 300–350 hp, they are sufficient.

Essential Supporting Modifications

A turbo kit alone will not safely produce 300+ horsepower. The 4G63 engine needs upgraded fuel delivery, engine management, and cooling. Below are the must-have mods with estimated costs.

Fuel System Upgrades

  • Upgraded Fuel Injectors (e.g., 650cc–950cc) – $300 (new) or $150 used.
  • In-Tank Fuel Pump (e.g., Walbro 255 lph) – $100
  • Fuel Pressure Regulator (optional but recommended) – $100

Engine Management & Tuning

  • ECU Tuning (ECMLink v3 or v4) – $600 (including cable and software). This is the gold standard for DSM tuning.
  • Wideband O2 Sensor (AEM or Innovate) – $200 for real-time air-fuel ratio monitoring.
  • Boost Controller (manual 2-stage or electronic) – $100

Exhaust & Intake

  • 3-inch Turbo-Back Exhaust – $400 (mandrel-bent, with downpipe and cat-back).
  • Cold Air Intake (with filter) – $75 (often included in the kit).

Cooling & Reliability

  • Upgraded Radiator (aluminum) – $200
  • Oil Cooler Kit – $150
  • New Spark Plugs (NGK BR8ES) – $15

Drivetrain Upgrades

  • Clutch (Stage 3+ for 300+ hp) – $500
  • Upgraded Intercooler Piping (if not in kit) – Already covered.
  • Boost Gauge – $40

Total additional parts: approximately $1,200 to $2,000 depending on how many items you buy new vs. used and whether you already have ECMLink.

Total Estimated Costs and Budget Considerations

Combining the turbo kit and supporting mods gives a range:

  • DSM T3 Turbo Kit – $1,200
  • Supporting Modifications (fuel, tune, exhaust, clutch, cooling) – $1,500
  • Grand Total – $2,700

If you already have a wideband or boost controller, subtract accordingly. Also factor in fluids, gaskets, and unexpected repairs—add another $300. So a realistic budget for a reliable 300+ hp 2G Eclipse is $3,000 to $3,500. This aligns with common DSM builds documented on forums like DSMTuners and STM Tuned.

Installation: DIY vs Professional

Most DSM enthusiasts perform the install themselves in a garage over a weekend or two. The 4G63 engine bay is tight, but well-documented guides exist (see VFAQ.com). If you lack mechanical skills, expect labor costs of $1,000–$2,000 at a reputable shop. DIY saves money but adds time; be prepared to buy specialized tools (e.g., torque wrench, metric sockets, tap and die for oil lines).

Hidden Costs

  • Gaskets and seals – $50
  • Coolant and oil – $50
  • Retuning after install – $200 (if you don't tune yourself).
  • New O2 sensor – $80 (if old one is sluggish).

Performance Expectations and Tuning

With the $1,200 T3 kit and proper fuel/tuning, a 2G Eclipse will easily hit 300 wheel horsepower on pump gas (93 octane). Many owners report 350 whp with the same setup after upgrading the intercooler and injectors to 950cc. Boost levels will be around 18–20 psi on the 50-trim turbo. However, the stock 7-bolt 4G63 bottom end is good for about 400 whp before considering forged rods and pistons. If you plan to exceed 350 whp, budget for an engine rebuild ($2,000+).

Tuning Tips

  • Use ECMLink to adjust fuel maps and timing. Do not trust the kit's “universal” chip.
  • Install a wideband O2 sensor and log while driving to avoid lean conditions.
  • Upgrade the bypass valve—cheap blow-off valves leak at high boost.
  • Always run a boost gauge and fuel pressure gauge.

Common Pitfalls and How to Avoid Them

  • Cheap intercooler core: Thin cores heat-soak quickly. Upgrade to a 3-inch thick core or a quality brand (e.g., ETS or Treadstone).
  • Oil line leaks: Use proper AN fittings and a restrictor for the turbo if using a ball-bearing center section.
  • Clutch slip: Do not skip the clutch upgrade—the stock clutch will not hold 300 hp. Budget for it.
  • Boost creep: The external wastegate included in cheap kits may be too small (38mm). A 44mm or 46mm gate is better for high-flow setups.
  • Tuning without knowledge: Spend time learning ECMLink on forums. A bad tune can destroy your engine.

Conclusion

Building a 2G Eclipse to 300+ horsepower using a $1,200 DSM T3 turbo kit is an achievable and rewarding project for the dedicated DIY enthusiast. Total costs will land around $2,500 to $3,500 when including essential supporting modifications, tuning, and miscellaneous parts. With careful planning, quality components where it counts (fuel system, ECU, clutch), and a methodical install, you can enjoy a reliable and potent street machine. Always consult community resources like DSMTuners and Road Race Engineering for detailed guides and troubleshooting. The 2G Eclipse platform remains one of the best values in performance tuning—this $1,200 turbo kit is just the starting point for a budget-friendly power build.