I would suggest surfing the internet for W/M (Water-Methanol) systems & how they work.
Darreli is spraying 100% Methanol... I assume only at the track.
I have a similar system from Torrie, that sprays windshield washer fluid (up to 50% Methanol), or in my case Snow "Boost Juice" which is 50/50. I do not run it on the street, other than when I am testing with WOT runs. My pump that sprays W/M is turned on by a boost sensor, that can be set to different pressures. It pulls the Boost Juice from the windshield washer reservoir, and sprays it thru a nozzle into the intake pipe going from the inter-cooler to the aluminum intake manifold. The nozzle is located just in front of the throttle body, and is positioned to spray at a slight angle towards the TB. How much volume you use, depends on the pump pressure and nozzle size. Usually less than 3 oz of fluid are used in a 1/4 mi run. So... a gallon of W/M solution goes a long way. Since windshield washer fluid usually contains methanol, I don't change back to blue washer fluid. I just use the Boost Juice to wash my windshield. Costs about $10. a gallon.
Methanol is a cooling agent, and also burns. Anything over 50% requires a hazmat permit for shipping as it becomes extremely flammable in stronger concentrations. Pure methanol boils at 95 deg F.
The purpose of spraying a methanol mix is to cool the air charge after the turbos, which lowers knock, and allows for more boost with the same levels of advance. Boost levels are all relative. One wants a consistently strong boost level, more than peaks of high boost. That is why we log our WOT runs. To maintain a safe tune, one also has to monitor FRP (Fuel Rail Pressure) in our engines to make sure the engine is getting enough fuel for the boost level. Lambda (bank 1 & 2) are also monitored to see how the Air/Fuel ratios perform throughout the run. The SCT Tuner and LiveLink 6.3 can monitor up to 18 parameters, from a list of over 100. Your tuner should be able to tell you what he and you should be looking at.
You are correct... you can't see a methanol fire.
Here is a great article on W/M Injection that contradicts some others opinions. Makes sense to me though....
www.rbracing-rsr.com/waterinjection.html