Is Water Injection a Cheap Substitute for Race Gas?

Anti-detonant injection system.

I have an old air force manual,"Aircraft engineering for pilots

as noted above the is a section that covers it.

Couple of quotes:  "The fluid itself does not increase engine power.  The function is to prevent detonation. It oes this so well that maximum power may be increased for short periods with out damage to the engine.

The term Water Injection is used in describing the ADI system.  This is misleading since the fluid is a mixture of water and alcohol."

This is a chapter on supercharges etc.

@Ottobon

If you want a rabbit hole to go down reading old test data:

http://www.not2fast.com/NACA/

Vigo said:

Latent Heat of Vaporization is basically the measure of how much cooling effect you're going to get and you can look it up for various things you could inject. Some of them are easier/safer to get, store, not clog up nozzles with, not corrode the inside of the pump with, etc etc.

While we agree that methanol is evil nasty stuff we may not be in agreement regarding all alcohol.  Methanol is coal tar while ethanol is corn ( wheat, potato’s, etc. ) 

We drink ethanol in beer wine and booze.  If we drink methanol first we go blind and then we die. 

In short methanol bad ethanol good. 

Now methanol has 116 octane to ethanol’s 114 octane. 

They are both alcohol so the latent effects of cooling are the same. 

And while methanol requires 90%+ bigger jets E85 only requires 66% bigger jets.  

In actual daily driving my V8 4X4 pickup averages 1-2 mpg less on E85 than on 87 octane gas. That’s because the timing is advanced using E85 and the actual power requirement to do the speed limit remains the same. 

Current price of E85  is $1.99 and 87 octane gas is $2.85. Roughly I save $10 per fill but after adjusting for poorer fuel mileage that means I only save $5.00 a fill. 

Even if the fuel savings wasn’t there the added power using E85 is!! And it’s really significant.  

GRM tested both E85 and methanol with race gas and regular 87 octane pump gas.  More torque and power using alcohol  15 more on a hundred horsepower Miata. Using alcohol  6 more using E85 3 more using race gas and 1 less using regular 87 octane.  

edmagoo said:

I think many people are a little too worked up over methanol or any type of alcohol with water injection. The NACA tests of water injection in WWII showed that doubling the rate of injection more than doubled the improvement. The tests also showed that 50/50 methanol was the best but 100% water was still very good.

In other words, you could inject 4 GPH of 50/50 or you could inject 5 or 6 GPH of 100% water to get similar improvements. I just pulled those flow rates out thin air but the idea is that you should just keep increasing the rate of 100% water until you start to lose ignition spark then back off and start mixing methanol.

Water injection should not kill spark until you are somewhere between 100% to 150% of the fuel rate (according to NACA tests). That's a lot of water before you even start to need methanol.

Remember NACA was trying to maximize power versus take-off weight of airplanes while we are trying to maximize power versus money spent. I don't mind a few extra pounds of water if it saves me having to manage methanol inventory.

Fear of methanol is valid and real, it’s nasty stuff.  But ethanol is also an alcohol and offers the same advantages. Well nearly the same. 114 octane compared to 116 for methanol.  

Ethanol is in beer wine and booze it’s made from corn,  rye, or potatoes , (etc )

Methanol is made from coal tar.  You drink methanol and first you go blind then you die!  Just splashing it on your skin can give you cancer. As can breathing it

in Short Ethanol good 

Methanol  bad  

kb58 said:

Oh it's awesome stuff, but I have to underscore the importance of being able to quickly detect when it's not being injected. Everyone's correctly noting the importance of detecting when the tank's low, but the real danger is when the injector nozzles partially or completely plug up. In that situation, the tank level switch, and driver think all is good and keep powering away, all while intake air temperature is going through the roof. Hopefully the ECU notices the high IAT or knock. Some systems (like AEM) use a flow sensor, which is really the only way to know for sure what's going on, but it's part of a $$$ kit.

BTW, another reason I got rid of it was due to smelling the methanol in the 50/50 water/meth mix while it was injecting. Read up on methanol - it's nasty evil stuff in any form. Alan Staniforth, author and builder of many British cars, died of lung cancer, thought to have been caused by his methanol  exposure in both liquid and fume form... For me, I chose to avoid the whole system, so to answer this thread's question - "No."

Two points.  

First about the need to quickly detect should something fail.  I think you’re looking at it backwards.   Why not confirm everything is working before blast off, so to speak.  First  use a system with a history of reliability. Windshield washers. Visible indication of function and fluid.  In the test mode it squirts on the windshield. In the race mode it squirts in the intake.  

Second water and 50% alcohol still won’t burn so it’s not a fire risk. In fact that’s exactly how you put out an alcohol fire, dilute the alcohol with water!  

Mount the plastic container in the passenger compartment.  Wanna check on the level of fluid? Look at it! 

Now we are in absolute agreement about how nasty methanol is.  I checked and local windshield washer fluid is only 10 % methanol and 3% dye 

someone claims windshield washer fluid can be up to 30% methanol . I won’t argue. 

But methanol isn’t the only alcohol that can be used.  

Ethanol isn’t made from coal tar like methanol is.  

If you drink ethanol in wine beer or booze it doesn’t make you blind and then kill you.  You don’t get cancer from breathing a little bit of it like you do from methanol 

in short 

ethanol good 

methanol bad. 

So why not mix your water with ethanol instead of methanol instead of  giving up on the whole idea?  

Tap water is pretty cheap and  denatured alcohol is cheaper than gasoline.  In high compression or high boost situation it’s an affordable solution  

I remember when our local dirt track modifieds ran methanol. The fumes while idling in the line up before the race were enough to make you looking for fresh air.

They gave up on it when the problems overran the benefits.

  And gasoline was getting better.

The water/alcohol injection is not directly connected to running alcohol as a fuel.