Methanol/Water Injection - Chemical Intercooling

Methanol/water injection makes power by lowering intake temperatures thus increasing intake charge density and 
increasing octane a little (re: methanol) thus reducing knock/detonation allowing your combustion to do work for 
you. If you don’t have [a lot of] knock it reduces power as it displaces air and fuel. 

Methanol/water injection is better than water injection for two reasons:

a) The alcohol evaporates quicker than water and lowers intake temperatures sooner. It can actually lower
temperatures in a NA car in the intake manifold prior to combustion. 

b) Methanol is a high-octane fuel like ethanol and this bumps your fuels octane (just like an ethanol blend fuel).
Further because it is a fuel the effect of displacing the air and fuel into the combustion chamber is reduced. 
Unfortunately again like ethanol it only has about 60% the power of petrol and thus cannot make up the difference 
it displaces let alone it and  the water. 

An annoyance for me with methanol/water injection is the need to refill the methonal/water tank. You could put a 
larger tank in your car, but then you are talking more weight. I've heard of people using 8 gallon tanks so refills
are nearly monthly, but this translates into an extra 80lbs in your car. Definately not insignificant. 

Methanol/water injection does not inject usable air like nitrous into your car’s engine. The oxygen in Methanol 
is used in its combustion and is not freed up (disassociated) to burn like nitrous. The oxygen in the water also 
does not separate at evaporation. Hydrogen and oxygen disassociates at tremendous temperatures (at 2000 C only 1%
of water is disassociated into Hydrogen and oxygen). Oxygen in nitrous on the other hand completely
disassociates at about 1300c. 

An interesting fact about methanol is that it is corrosive to aluminum. I haven’t heard about any problems with this,
but I also haven’t heard of my imports using it long term. In particular I’d be concerned about my intake manifold 
and possibly the head. The head is not likely to be a problem because combustion takes care of the methanol, but 
the intake system would certainly be a long-term concern for me. 

This all adds up to methanol injection being a band-aid solution when you are pushing your motor beyond its efficiency 
range and knock is an issue. It can make a huge difference if you are boosting out of your efficiency range and your
intercooler cannot lower the intake temperatures enough to reduce detonation. It can also be beneficial on very hot
days where [again] you have detonation issues. If on the other hand you are running efficiency it’ll reduce your power. 

Jackson Racing Supercharger Recommendations

In the case of an EATON blower it can make a lot of sense to run methanol/water injection if an intercooler is not 
available and you are pushing high boost (above 8 psi). EATON blowers have relatively lower adbiabaitc efficiencies
and thus above 8 psi the intake temperatures are very high (usually 180f/82c or higher). This cause detonaton issues
and intercooling is VERY helpful. In particular I’d suggest running methanol/water injection on any H22 or D series
motor making over 8 psi. On B series motors I’d strongly suggest the LHT intercooled intake manifold. 

Veris