Originally Posted by wstar

I've never really seen a water/methanol system in use, or done a whole lot of research on the subject other than to know the basics. So basically this kit looks at the MAF sensor to see airflow data, and regulates a mist of water and alcohol into the intake air stream that's proportional to the airflow (or in the case of the stage 3 kit, uses I'm guessing a CAN connection to the car to look at more precise data instead of just tapping the MAF signal?).

With the S3, we inject based on fuel injector duty cycle actually. Single best data type to control injection, because IDC is based not only on MAF data, but RPM, TPS, various temperatures, etc in these cars. So you essentially get a more proper injection curve compared even to MAF based injection.
In any case, my random methanol newbie questions:

1) How much HP increase would you expect on a WOT Dyno run with a system like this on an engine like ours (NA, not turbo'd)?

What it really boils down to is that we add 20-25 points of octane. So what an engine can do on race gas, it can now do on pump gas. Its not a case of automatically getting the power so much as completely changing the kinds of timing advance and AFR you can get away with before you hit detonation and heat issues in the combustion chamber.


2) Does the ECU need to have new maps made to advance timing during WOT in order to take advantage of the water/meth injection? Or are we just relying on the fact that our ECUs are smart enough to self-adjust the timing as far as the fuel mix and temps allow? And in either case, how does the ECU know to back off again (other than to see bad knock happening first and *then* retard) when the tank goes empty in the middle of a drive then and you're back to normal fuel mix?

typically a more aggressive tune is nice to really take advantage of the system. If the ECU is going to advance timing very far as opposed to a just a few degrees, then a lot of the tuning is being done automatically. but most ECUs will not do much in terms of AFR beyond their normal settings, which are typically far richer than a car with our system needs.


3) How long does the tank last? Is 3 quarts basically enough for 2-3 passes at the drag strip and then you refill? Or is 3 quarts more like "drive two hundred really hard miles with lots of WOT before it goes empty", or?

Typically a 3QT will last about 16 gallon of gas. The harder you push the more the system uses, but then too you are using a lot more gas too. Even if you really lay into it you would probably get north of a half tank of fuel out of the standard 3QT tank.