How do I convert my LS swap to E85?

What changes: E85's stoichiometric ratio is about 9.7–9.8:1 (gasoline ≈14.7:1), so the engine needs a lot more fuel for the same power. LSX Magazine's conservative BSFC values (0.80 vs 0.55) work out to about 45% more fuel. Many sources quote ~30%; the difference comes from the BSFC assumed. Speedway's chart sizes E85 injectors about 19–25% larger than gasoline for the same hp.

What you need:

1. Injectors sized for E85 (see the injector chart), ethanol-compatible (aftermarket injectors use corrosion-resistant materials).
2. Fuel pump with enough flow for E85 and rated for ethanol.
3. Ethanol-safe lines (e.g., PTFE-lined hose).
4. A tune for E85. For pump E85, whose ethanol content varies, add a flex-fuel sensor so the ECU can adjust.

Several factory LS engines were already E85-capable (e.g., L59, LC9, LMG, L9H, L94, L99, L20, L96, L77, LH9 per GM engine tables), which helps with injectors and calibration.