Upgrading your DSM (Eagle Talon, Mitsubishi Eclipse, or Plymouth Laser) with a Buschur Racing E85 fuel system is one of the most effective modifications you can make to unlock serious horsepower while taking advantage of ethanol’s superior knock resistance and cooling properties. E85 fuel has a higher octane rating (typically 105–110) than pump gas, and it runs cooler in the combustion chamber, allowing you to run more boost and advance timing without detonation. The Buschur Racing E85 fuel system kit is engineered specifically for DSM platforms, providing the necessary flow capacity and ethanol compatibility to support 500+ wheel horsepower. This guide will walk you through the entire installation process, from preparation to final tuning, and give you real-world performance expectations.

What You Will Need

Before beginning, gather all tools and components. Having everything on hand will prevent interruptions and ensure a safe installation.

Tools & Safety Gear

  • Basic hand tool set: wrenches (metric 10mm–17mm), socket set, screwdrivers (flathead and Phillips)
  • Fuel line cutter (for cutting PTFE or nylon braided lines cleanly)
  • Fuel pressure gauge (mechanical or electronic with appropriate adapter)
  • Safety goggles and chemical-resistant gloves
  • Shop towels or rags for fuel spills
  • Jack and jack stands (if working under the vehicle)
  • Trim panel removal tools (for accessing fuel pump in the hatch area)
  • Multimeter (for verifying electrical connections)

Components Included in the Buschur Racing E85 Kit

  • Brushless or geared E85-compatible fuel pump (e.g., Walbro 450 lph or similar)
  • High-pressure E85-rated fuel filter (10-micron or finer)
  • PTFE-lined stainless steel braided fuel lines (feed and return)
  • AN fittings (usually -6AN or -8AN depending on power goals)
  • Fuel pump hanger assembly or mounting bracket
  • Fuel pressure regulator (if not already upgraded)
  • Installation hardware and instructions

Step 1: Preparing Your Vehicle

Park the vehicle on a level surface, set the parking brake, and chock the wheels. Disconnect the negative battery terminal to eliminate any chance of sparks or electrical shorts while working near fuel. Allow the engine to cool completely before opening the fuel system. Also, work in a well-ventilated area, preferably with a fire extinguisher rated for fuel fires nearby. Safety is paramount when handling gasoline or E85.

Step 2: Removing the Stock Fuel System

This step involves depressurizing the fuel system and removing the factory pump, filter, and lines. Work methodically to avoid damaging any components you may need to reuse temporarily.

Relieve Fuel Pressure

Locate the fuel pump fuse in the under-hood fuse box (or the pump relay). Remove the fuse, then crank the engine for about 10 seconds until it stalls. This relieves residual pressure in the fuel lines. Repeat if the engine restarts. Some tuners prefer to loosen the fuel cap to release tank pressure.

Disconnect Fuel Lines

Using the appropriate wrench, disconnect the fuel feed line from the fuel rail and the return line (if equipped) at the fuel filter or tank. Have shop towels ready to catch any remaining fuel. For 1G and 2G DSM models, the fuel filter is typically mounted on the firewall near the driver’s side strut tower. On some models, you may also need to disconnect the vapor line.

Remove the Stock Fuel Pump

Access the fuel pump through the access panel in the rear hatch area or by lowering the fuel tank. DSM fuel pump access is usually under a black plastic cover in the trunk. Remove the cover and disconnect the harness connector. Use a fuel pump removal tool or a flathead screwdriver to release the retaining ring. Carefully lift out the pump assembly. Note the orientation of the pump and the sock filter. Remove the pump from the hanger. Discard the old pump and sock filter.

Remove the Stock Fuel Filter

Unbolt the fuel filter from its bracket. It will be full of fuel, so tilt it into a drain pan. Remove the banjo bolt or AN fitting connections. The filter may also be integrated into the pump hanger on some 2G models. Dispose of the old filter responsibly.

Step 3: Installing the Buschur Racing E85 Fuel System

With the factory components removed, you can now install the high-flow E85-compatible parts. The kit is designed to be a direct replacement with minimal modification.

Mount the New Fuel Pump

Attach the brushless or high-output pump to the new hanger or the factory hanger using the supplied brackets. Ensure the pump is oriented correctly so the pickup sock sits at the bottom of the tank. Do not reuse the old rubber isolators if they are degraded – use the provided mounts. Connect the pump wiring harness, paying attention to polarity. Some aftermarket pumps have a specific ground wire routing. Use heat-shrink butt connectors or solder for reliable connections.

Install the Fuel Filter

Mount the new 10-micron E85-rated fuel filter in a location that’s accessible for future changes. Many DSM owners mount it on the passenger side shock tower or on the firewall using a bracket. Use supplied AN fittings. Tighten securely but avoid over-torquing aluminum fittings.

Route the New Fuel Lines

Using the PTFE-lined stainless braided hose, run the feed line from the pump outlet to the fuel filter, then from the filter to the fuel rail. Run the return line from the fuel pressure regulator back to the tank. Use the provided AN connectors. Make clean cuts with the fuel line cutter to avoid fraying the stainless braid. Slide the hose onto the fitting and tighten the nut. All connections must be leak-free; consider using thread sealant on NPT fittings (not on O-ring style fittings).

Connect to the Fuel Rail

Attach the feed line to the stock fuel rail inlet, or if you have an upgraded fuel rail, connect accordingly. If your DSM has a return-style fuel system (1990-1999 models), ensure the return line is connected to the regulator. For vehicles that were originally returnless, you may need to install a new fuel rail or adapt the system. The Buschur kit often includes an adaptor for that scenario.

Fuel Pressure Regulator Installation

If your kit includes an adjustable fuel pressure regulator (e.g., Aeromotive or Fuelab), mount it in a location where you can easily adjust it and connect a vacuum line to the intake manifold. Set the base fuel pressure to 43.5 psi (300 kPa) with the vacuum line disconnected, as recommended for most E85 setups. Reconnect the vacuum line after setting.

Step 4: Upgrading the Fuel Management System

A larger fuel system means nothing without proper control. Your DSM’s stock ECU cannot compensate for the higher flow rate and different stoichiometric ratio of E85 (around 9.8:1 compared to 14.7:1 for gasoline). You will need a standalone ECU, a flashable stock ECU (e.g., ECMlink or a chip tune), or a piggyback fuel controller. Do not attempt to run the car with only a larger fuel system and no tuning – severe engine damage will result.

ECU Tuning Solutions

  • ECMLink V3 – Most popular for 1G/2G DSMs. It allows full control over fuel maps, boost, timing, and compensates for larger injectors and E85.
  • AEM Infinity or Haltech – Premium standalone options for high-horsepower builds.
  • Speed Density Conversion – Removing the mass airflow sensor and tuning via map sensor improves airflow measurement for high-boost E85 setups.

If you are not comfortable tuning yourself, schedule time with a reputable DSM tuner. A dyno session will ensure you safely extract maximum power from the E85 fuel system. Buschur Racing offers tuning services and can provide base maps for many setups.

Larger Fuel Injectors

The stock 450cc/min injectors will be grossly inadequate. For a typical E85 upgrade targeting 400-500 whp, you will need 1000-1200cc injectors. For higher power levels, 1600-2150cc injectors are common. Ensure the injectors are ethanol-compatible (Pico, Bosch, Injector Dynamics).

Step 5: Testing the System

With all mechanical and electrical connections made, it’s time to prime the system and check for leaks.

Prime the Fuel Pump

Reconnect the battery. Turn the ignition key to the ON position (do not start). Listen for the fuel pump to prime (a brief whirring sound). If the pump doesn’t activate, check your wiring and fuse. With the key ON, you should see fuel pressure rise on your gauge. Turn the key OFF if pressure builds normally.

Leak Check

Inspect every connection: pump hanger, filter, rail, regulator, and all AN fittings. Use a clean rag to dab around each joint. Any sign of fuel wetness indicates a leak. Tighten or re-seat the fitting as needed. Never start the engine with active leaks. Repeat the prime cycle several times to verify no leaks under pressure. Also check the return line for flow back to the tank.

Start the Engine

Once you’re confident the system is tight, start the engine. It may take a few seconds of cranking to push fuel through the injectors. The engine should idle smoothly once the ECU has been calibrated for E85. If it runs rich or lean, adjust the fuel pressure or injector scaling in your tuning software. Let the engine reach operating temperature while monitoring fuel pressure and looking for any drips.

Final Pressure Adjustment

With the engine running, disconnect the vacuum line from the regulator. Fuel pressure should rise by the amount of manifold vacuum (typically 8-15 psi). Reconnect the line and verify pressure drops accordingly. If using a boost reference regulator, ensure the pressure rises 1:1 with boost.

Performance Results

After installing a Buschur Racing E85 fuel system and tuning the ECU properly, expect dramatic improvements. Real-world results from DSM owners on forums like DSMTuners and documented Buschur builds show:

  • Horsepower gains of 25-35% over a comparable 93-octane setup with the same boost level – attributable to E85’s latently higher octane and cooling effect allowing more ignition advance.
  • Throttle response sharpens noticeably due to the ethanol’s high oxygen content and improved fuel atomization from the new pump and lines.
  • Reduced tendency for knock even at high boost. Many tuners report being able to run 2-3 psi more boost safely compared to pump gas.
  • Lower exhaust gas temperatures (EGT), which helps preserve turbocharger and engine longevity.
  • Slight fuel economy decrease (E85 contains about 30% less energy per gallon than gasoline), but many find the power gains worth the trade-off, especially for a weekend warrior or track car.

Note: Actual results vary based on turbo size, engine condition, tuning quality, and supporting mods (intercooler, boost controller, etc.). A properly tuned DSM with a Bushcur E85 system can comfortably achieve 450-550 whp with a standard journal bearing turbo (e.g., FP HTA68 or Garrett GT35R) without breaking the bank.

Maintenance and Long-Term Considerations

E85 fuel requires a few extra considerations compared to gasoline. Ethanol is hygroscopic (absorbs moisture) and can be corrosive to some metals and rubber if not properly handled. The Buschur Racing kit uses ethanol-compatible materials (stainless steel, PTFE, and Viton seals). Still, follow these tips:

  • Change the fuel filter after the first 500 miles to catch any debris from the installation process.
  • Inspect the pump wiring annually – vibrations can loosen crimps.
  • Avoid storing the car with E85 for more than 2-3 months without a stabilizer (use an ethanol-compatible fuel stabilizer).
  • If you live in a humid climate, consider draining the tank and running a tank of premium pump gas before long storage periods.
  • Check for leaks at the pump hanger seal – E85 can degrade the rubber gasket if not the right material. The kit includes a proper seal.

Common Pitfalls to Avoid

  • Skimping on the fuel pressure regulator: A cheap or non-reference regulator can cause erratic pressure, especially under boost. Invest in a high-quality unit.
  • Using nylon or rubber hose: E85 will cause swelling and permeability in standard rubber fuel hose. Only use PTFE or an approved ethanol-rated rubber hose.
  • Underestimating electrical demand: Some high-output pumps draw over 20 amps. Use a relay with thick gauge wiring directly from the battery. The factory wiring is insufficient.
  • Relying on a base tune from the internet: Every DSM is different. Get a custom tune from a professional who understands E85.

Conclusion

Installing a Buschur Racing E85 Fuel System in your DSM is one of the highest-return modifications you can make. It’s a straightforward project for a moderately experienced DIY mechanic, and the power gains are substantial. By replacing the restrictive factory fuel pump, filter, and lines with ethanol-compatible, high-flow components, and by following up with proper ECU tuning, you can transform your DSM into a reliable, high-horsepower machine that thrives on E85. The key is preparation, meticulous assembly, and a willingness to invest in professional tuning. With the system in place and a safe tune, you’ll enjoy crisp throttle response, reduced knock, and the unique thrill of a 500-horsepower DSM that runs on pump ethanol. For more information on compatible tuning software and support, check out the ECMlink website or the Buschur Racing product page.