Upgrading your LS3 Camaro’s fuel system is one of the most effective ways to unlock serious horsepower gains. And when you add E85 fuel into the equation, the results can be dramatic. With BTR’s E85 fuel system upgrade, you can expect over 70 horsepower at the wheels for less than $1,200. This isn’t just a theoretical number; it’s a proven real-world improvement that makes this kit a standout value for any LS3-powered car. In this detailed guide, we’ll cover everything you need to know: why E85 is a game-changer, what the BTR kit includes, how to install it, what performance gains are realistic, and the key considerations before making the switch.

Why E85 Fuel?

E85 is a blend of 85% ethanol and 15% gasoline. It’s widely available across the United States, particularly in the Midwest, and offers several distinct advantages over traditional pump gas, especially for high-performance LS3 engines.

Higher Octane Rating Means More Power

E85 typically has an octane rating of around 100 to 105 (R+M/2 method). That’s significantly higher than premium pump gas, which usually sits around 91-93 octane. Higher octane allows you to run more ignition timing and higher boost (if forced induction is involved), leading to a much more aggressive tune. Naturally aspirated LS3 engines also benefit: advanced timing maps extract more power without risking detonation.

Cooler Combustion Temperature

Ethanol has a latent heat of vaporization roughly three times higher than gasoline. As it evaporates in the intake charge, it pulls heat out of the air and cylinder walls. This reduces intake air temperatures and lowers combustion chamber temperatures. Cooler combustion suppresses knock, allowing even more aggressive tuning. It also helps reduce exhaust gas temperatures, which is beneficial under sustained high-load conditions like track days or long pulls.

Cost-Effective Performance

E85 is often priced lower than premium gasoline when comparing energy content adjusted cost. While you will burn roughly 25-30% more fuel by volume to make the same power (since ethanol contains less energy per gallon), the cost per mile of power is often lower than running race gas or high-octane pump blends. For many enthusiasts, the net fuel cost is comparable or even cheaper than premium. Plus, you avoid the steep markup of specialty fuels.

Environmental and Material Considerations

Ethanol is renewable and burns cleaner than gasoline, producing fewer CO and hydrocarbon emissions. However, it’s also hygroscopic, meaning it attracts water. This can lead to corrosion in fuel systems not designed for ethanol. Older rubber lines, gaskets, and certain metals can degrade. That’s why a dedicated E85 conversion kit—like the one from BTR—is essential. The kit includes components that are resistant to ethanol’s corrosive effects.

BTR’s E85 Fuel System Upgrade for LS3

BTR (Brian Tooley Racing) is well-known in the LS community for its high-quality valvetrain components, but they also produce comprehensive fuel system upgrades. The kit is engineered specifically for LS3 engines (found in 2008+ Chevrolet Corvette, 2010+ Camaro SS, and many other GM vehicles) and provides everything needed to safely run E85 at elevated power levels.

What’s Included in the Kit

  • High-Flow Fuel Injectors: The kit includes 42 lb/hr or larger injectors (often 50 lb/hr or 60 lb/hr depending on the specific variant). These injectors flow enough fuel to support 70+ horsepower gains over the stock setup.
  • Upgraded Fuel Pump: A high-flow in-tank fuel pump (usually a Walbro 450 or DW400) provides the extra volume and pressure needed when running E85. The stock pump can’t keep up with the increased fuel demand.
  • Custom Fuel Lines and Fittings: Ethanol-safe PTFE-lined hose and anodized adapters replace the stock plastic or rubber lines. The kit includes all necessary connectors for a direct-fit installation.
  • Calibration Support / Tuning Guide: BTR provides tuning parameters or a recommended starting point for the fuel system. They often include access to a base tune file or instructions for popular tuning platforms like HP Tuners.

Some versions of the kit may also include a fuel pressure regulator or a boost reference kit for forced induction applications. The standard naturally aspirated setup is everything you need for a bolt-on E85 conversion.

Installation Process

Installing the BTR E85 fuel system upgrade is a moderate-level DIY project. You’ll need basic hand tools, some mechanical experience, and access to a tuning interface. Plan for a full weekend if you’re taking your time. Here’s a detailed step-by-step breakdown.

Preparation

Gather all tools: socket set, screwdrivers, fuel line disconnect tool, torque wrench, safety glasses, and gloves. Disconnect the battery negative terminal to avoid any electrical shorts. Relieve fuel pressure by pulling the fuel pump fuse and cranking the engine briefly. Work in a well-ventilated area and have a fire extinguisher nearby.

Removing the Old Fuel Pump

You’ll need to access the fuel tank. On the Camaro, the pump is accessed through an access panel under the rear seat cushion. Remove the seat, peel back the carpet/insulation, and remove the access panel bolts. Disconnect the electrical connector and fuel lines from the pump module. Lift the old pump assembly out carefully, taking note of the orientation. Transfer the fuel level sender and any rubber grommets to the new pump assembly. Install the new BTR pump in the same orientation and reinstall the module with a new seal (supplied).

Replacing the Fuel Injectors

Remove the intake manifold to access the injectors. For the LS3, this means unbolting the manifold, disconnecting the throttle body, and removing vacuum lines. The fuel rail comes off with six bolts. Carefully pull the old injectors out. Lubricate the O-rings on the new BTR injectors with a small amount of clean engine oil, then press them into the fuel rail and intake runners. Reinstall the fuel rail and torque to spec. Replace the intake manifold gaskets and reassemble.

Installing the Fuel Lines

The BTR kit includes ethanol-safe lines that replace the stock fuel feed and return lines (if your vehicle has a return-style system—most LS3 Camaros are returnless, but the kit adapts to that). For returnless setups, you may need to install a return line and a fuel pressure regulator. BTR provides instructions for both setups. Connect the PTFE hose using the supplied AN fittings. Make sure all connections are tight but not overtightened. Double-check for any kinks or rubbing points.

Fuel Pressure Regulator Setup (If Required)

For return-style conversions, mount the regulator somewhere safe, typically on the firewall or near the fuel rails. Connect the supply line to the regulator, the return line back to the tank, and the vacuum reference line to the intake manifold. Set base pressure to 58 psi (typical for LS applications) with the engine off and vacuum line disconnected.

Tuning the ECU

This is the most critical step. Running E85 requires recalibrating the air/fuel ratio, ignition timing, and fuel injector data. Injector flow rates, short pulse adder, and latency must be updated. You’ll need software like HP Tuners or a professional tuner. BTR provides a base calibration file that gives you a safe starting point. Load the tune, prime the fuel system (cycle the key a few times), and check for leaks. Start the engine and verify fuel pressure and idle quality. Then perform a WOT datalog to adjust the fuel trims and timing. Expect to spend several hours on the dyno or road tuning to dial it in perfectly.

Performance Gains: What to Expect

After installation and professional tuning, LS3 Camaros typically see 70–90 wheel horsepower gains with this BTR kit. Here’s a realistic breakdown:

  • Stock LS3 baseline: 400-410 wheel horsepower (depending on drivetrain losses).
  • With E85 + tune: 470-500 wheel horsepower.

That’s a 70-90 whp increase for under $1,200 in parts. To put that in perspective, a full exhaust system and cold air intake might yield 30-40 whp for similar cost. The E85 fuel system upgrade gives you more horsepower per dollar than nearly any other bolt-on modification.

Dyno results from BTR and customer forums confirm these numbers. A 2010 Camaro SS with long-tube headers, a cold air intake, and the BTR E85 kit made 477 whp and 455 lb-ft on a Mustang dyno—over 80 whp over stock. Even on a bone-stock engine with only the fuel system and tune, gains of 70+ whp are common.

Considerations Before Upgrading

While the BTR E85 kit is an excellent value, there are several factors you must consider before pulling the trigger.

Fuel Availability

E85 is not available at every gas station. Check the Alternative Fuels Data Center map to see if stations near you carry it. If you don’t have easy access, you may need to stick with pump gas or invest in a flex-fuel sensor and tune that can adapt to both fuels.

Engine and Fuel System Capacity

Even with the BTR kit, you need to ensure your fuel system can handle the power level you’re targeting. The kit supports up to around 500-550 wheel horsepower on E85. If you later add forced induction or nitrous, you’ll need bigger injectors and a more capable pump (BTR also sells step-up kits). Verify that your stock fuel lines and tank are in good condition—corroded or leaking lines will undo all your hard work.

Regular Maintenance and Corrosion Prevention

E85 absorbs water from the atmosphere, which can cause phase separation and corrosion. Always store your car with a full tank of E85 (or drain the system if storing long-term). Replace the fuel filter frequently—many owners change it every 10,000 miles when running E85. Use a fuel stabilizer designed for ethanol if you won’t drive the car for a month or more.

Tuning Costs

The kit itself is under $1,200, but you must factor in tuning costs. A professional dyno tune can range from $400 to $800. If you purchase HP Tuners credits and tune it yourself, the upfront cost is higher but pays off over multiple vehicles. Either way, budget an additional $500-$800 for a proper calibration.

Changing the fuel system and tuning may affect emissions compliance. In some states, tampering with the emissions system (including the engine calibration) is illegal for highway use. E85 itself burns cleaner, but you need to check local regulations. Many race-only cars are exempt, but a street-driven Camaro may need to retain the stock tune for smog checks.

Alternatives to the BTR Kit

If the BTR kit doesn’t fit your needs, there are other options. Many companies offer E85 conversion kits for the LS3, including Lingenfelter Performance Engineering and Haltech. However, BTR’s combination of quality components, proven gains, and competitive pricing makes it a top choice. You could also piece together your own kit using individual parts, but that often ends up costing more and requires extra troubleshooting.

Conclusion

BTR’s E85 Fuel System Upgrade is one of the most cost-effective performance modifications available for the LS3 Camaro. With over 70 horsepower gains achievable for under $1,200 in parts, it delivers more bang for the buck than almost any other bolt-on. The installation is straightforward for a mechanically inclined enthusiast, and the tuning opens the door to a completely different driving experience—stronger throttle response, more torque across the rev range, and the satisfaction of running a high-octane renewable fuel.

Before you start, check local E85 availability, plan for professional tuning, and commit to the regular maintenance that ethanol demands. If you can do that, you’ll unlock a new level of performance that makes your LS3 Camaro feel like a completely different car. For more details on the kit, visit BTR’s official product page or consult your local tuner for a custom calibration tailored to your specific setup.