The stoichiometric ratio commonly known as the Air-Fuel Ratio (AFR) is a ratio of the particles of air to the fuel. As you notice on the chart different fuels have different AFR's. These ratios represent the amount of air it takes to completely burn the desired fuel.
These air fuel ratios are extremely important for dyno tuning because they are indicators of how rich or lean your engine is. For regular fuel (premium gasoline) Rich is considered to be AFR between 1 and 14.7 and lean is considered to be 14.7 or more. To know exactly what your air fuel ratio is it is recommended to buy an Air/Fuel ratio gauge and wideband sensor which can be found in our store.
Octane plays a key role in your performance as it will help you or hurt you tremendously. Most know that the higher the octane rating the more power you can make, but why? Back during the First World War we discovered that tetraethyl lead or (TEL) can be added to gasoline to increase the octane rating.
Octane numbers are the amount of compression the fuel can take before it combusts without spark. For an example 87 octane will combust naturally without spark before an octane rating of 93. When your fuel combusts without spark it creates knock in the engine which causes loss of power and damages your engine. The reason for higher octane fuels is to keep the knock down which allows you to produce more power. Methanol injection has been a quick and easy way of increasing your octane rating.
The benefits to methanol injection are obvious when you sit down and look at the facts. With methanol injection your engine will see octane ratings of 10-25 points higher. If you are using 93 octane fuel with methanol injection you can see octane numbers between 103-118. Q16 which is a common racing fuel has an octane rating of 116 but it costs $16.40 per gallon.
Methanol on the other hand is around $3.00 per gallon and is mixed 50% with water so you would actually be getting 2 gallons for the price of one which turns out to be about $1.50 per injected gallon. The same octane rating is achieved for a quarter of the cost and the best part about it is that you can regular gasoline at any gas station.