Water/Methanol Injection
Two jobs in one: mix exactly the water/methanol ratio you want, then see what that spray is worth — litres per hour, estimated intake charge temperature drop and how much fuel energy the methanol itself adds.
Make the mix
Methanol
2.5 L
Water (distilled)
2.5 L
Total
5 L
Volume ratios are the industry convention (50/50 = half methanol, half water). Methanol doubles as antifreeze — a 50/50 mix stays liquid well below freezing. Use distilled water: tap water scales up nozzles and pumps. Methanol is toxic and burns with an invisible flame — gloves, ventilation, and never store it in the cabin.
Charge-cooling estimate
Theoretical ΔT
33.4 °C
Estimated real ΔT
−20.1 °C
Spray flow
30.98 L/h
Methanol fuel energy
+5.7%
Water flow: 13.71 L/h
Methanol flow: 17.27 L/h
Air mass: 1,368 kg/h
The estimate assumes full evaporation and ignores heat re-entering from the manifold — treat it as the ceiling, tune the real factor against your own IAT logs (the Datalog Viewer is right here). You’re also adding methanol fuel: re-check AFR and don’t exceed ~25% of fuel mass without a purpose-built tune — and never let a system full of water get ingested at once (hydrolock).
Good to know
- Cooling physics: full evaporation of the mix absorbs latent heat (water ≈ 2260 kJ/kg, methanol ≈ 1100 kJ/kg) — the estimate assumes ideal evaporation, so real drops land lower.
- Tune the “real-world factor” against your own IAT logs: better atomisation, hot-plate placement on the intercooler and lower charge temps all claw back efficiency.
- Typical starting point: 1–2% of air mass, or 10–25% of fuel mass. More isn’t automatically better — over-spraying quenches combustion and risks hydrolock.
- Use distilled water and automotive-grade methanol; methanol is toxic and its flame is near-invisible. Mount the tank safely and check for leaks regularly.