Learn me supercharging fo the challenge

In reply to frenchyd :

So could you rig an injector of some sort in the intake track to fire an ethanol mix as it sees boost? If you put it before the boost adder, it wouldn't even need to be high pressure, just high enough volume right?

In reply to singleslammer :

Exactly. They already make and sell a FMU that works on that principle . Last time I bought a used one I paid $45.  I used it to trick the computer in an early XJS 

methanol is cheap about $3 a gallon but wear arm length rubber gloves, a fuel apron and really good mask  plus something so you don't breath the fumes. 

Ethanol isn't like that. It's just really strong whisky. But when they mix it with gas to get E85 unless you pay for the good stuff you won't get the benefits you do with methanol 

In reply to singleslammer : you could use the windshield washer tank  it's already meant to handle alcohol and if you figure out a trigger to act on boost it has a pump to squirt the alcohol into the intake tract .  

frenchyd said:

In reply to singleslammer : you could use the windshield washer tank  it's already meant to handle alcohol and if you figure out a trigger to act on boost it has a pump to squirt the alcohol into the intake tract . 

Keep in mind, if you inject after the blower (which is the common) the intake will be pressurized, so you'll need to ensure the windshield washer pump is pressure referenced or the washer bottle is pressurized or you'll not get any fluid into the intake.

If you inject before the blower, then you'll have to compress the liquid in the rotors, which may or may not be ideal, but you won't need a pressurized vessel or a high pressure pump.

In reply to Stefan :rotors already compress moisture on a rainy day so alcohol will not only cool the supercharger itself making it more efficient but also cool the inlet charge.  

While tempting to add water to the inlet charge it doesn't have the same cooling effect pure alcohol has 

plus alcohol will help in the need to richen the fuel mixture under boost  

the sole problem is it adds in a linear fashion ( the same amount of fuel no matter how much boost is created)  so the full extra fuel charge should be added through the injectors and the modest amount added through  The intake

Technically there is no compressing of any liquids ever, anywhere, and also technically the term rotors would apply to roots or screw type superchargers but not centrifugals as is being discussed here. 

My personal opinion on the cheap approach to this is an adjustable rising rate fuel pressure regulator (colloquially called FMUs although that is a vague term that is already being used here to describe an electrical box) and a zener diode on the MAP circuit. 

The RRR (rising rate regulator) not only raises fuel pressure with boost, but raises it at a rate higher than 1:1. 'Good' ones (talking tunability here, not quality) have an adjustable rate of gain in the form of a basic needle valve bleeding boost/reference pressure off the air diaphragm. Non-adjustable ones either don't adjust at all or have to be taken apart and internal parts swapped out to adjust rate. That's crap unless you're copying a known-good recipe. All of them should have adjustable base pressure, which also lets you compensate for larger injectors by lowering base pressure (to a point..).   With any RRR setup you really ought to spend money on an in-cab fuel pressure gauge because there is NO guarantee that what you're asking for with the RRR is what you actually get in terms of fuel pressure. That is up to the limitations of your pump. Untold thousands of people have tried to 'tune around' a fuel pressure ceiling that they didn't know existed. You can stick a gauge on the rail under the hood but the thing is that you have to watch pressure WHILE at maximum demand. So you can add pressure to the RRR diagphragm and watch your fuel pressure go up while the car is sitting there idling, but what you need to know is that it can make the pressure WHILE supplying the full volume required to make your peak HP. You can't really test for that while stationary unless you're on a dyno, thus the need for in-cab  (or maybe on-windshield) monitoring while driving. 

The zener diode is basically a pressure regulator for voltage. Once voltage goes above a certain point the diode will allow flow across it. So, on a MAP circuit which is three wires (5v reference voltage, signal return voltage, and ground) you would hook it between the signal wire and ground wire so that the computer never saw voltage higher than ~4.3-4.7v (depending which one you buy), or in other words never sees 'pressure' higher than atmospheric. If you know how to find them they are dirt cheap. Like buy a whole bag of them for single digit dollars. In the past these things have been called map clamps, missing links, etc, which are all terms made up by people that don't understand what the thing does. We can just call it what it is, a zener diode!