Water injection Info.

Old Colt · Post by **Old Colt** » Wed Dec 13, 2006 9:21 am

Bill asked me for a bit of info on implementation of water injection.
I will aim this at the Proper way of doing a water injection not the simple, just spray it at the throttle body.
I am not the guru of this, so there is more out there than I will bring to the table here.

The water injection has two jobs to do, one cool the charge air, two forestall detonation.
Those may sound like the same goal but they aren't.

To make torque we need to increase the pressure in a cylinder during a burn. The greater amount we can change that temperature is a greater push on the piston. We have an upper limit to the temperature, but we do not have a lower limit. With this in mind we can spray a water or water/ alcohol mix up stream for some evaporational cooling. Simple.
But we are introducing Alcohol, now here we have a fluid with some interesting properties. This stuff can cool a surrounding surface while it burns and this gives it a very strong resistance to detonation.
So lets use this. This will be in cylinder cooling. This is much more complicated than buying some American made injection system and squirting water somewhere and using washer fluid for it's freeze protection.
We will now need to insure we get a similar volume in each cylinder so we want individual nozzles.
It is determined that spraying about 15 to 20% alcohol to fuel ratio to be about right. So obviously we need proper control in relation to the fuel injection. This is not so hard, even Megasquirt has this covered.
Now for the more difficult task and where the real gains are. The alcohol can accept much more ignition timing than Gasoline. When we properly inject water/ alcohol in the cylinder we can advance our timing back into a range similar to a non boosted engine. Get this wrong and the engine comes apart real quick. Get it right and you get real big power even on basic pump gas. Like 30+ boost and 28 deg timing on 91 octane. That is big power for a street car or race.
So to go here a water injection system needs to have control over the ignition and be fully mapable on a dyno.
The water alcohol ratio needs to be a mix that is consistent, so this you do yourself.
The power this can provide is there on a 100 degree day as well as on a cold one.

Post by **DJpowerHaus** » Wed Dec 13, 2006 5:21 pm

Why not just run E85 from the fuel injectors?

Old Colt · Post by **Old Colt** » Wed Dec 13, 2006 8:49 pm

Most standalone units actually will not drive the water system. We are talking about water injection systems that are more expensive than most stand alone fuel systems.

I do not have much experience with the E85 fuels but they are formulated to lean a fuel charge. I would be afraid of trying to tune to a fuel blend such as that due to the inconsistency of mix part way due to the fact that the alcohol can flash off very quickly.

Post by **DJpowerHaus** » Wed Dec 13, 2006 10:20 pm

Lord you love to throw around numbers that don't really a answer any questions. I just like Carrying around 1 tank of fuel.. not a tank of fuel and a tank of water/alcohol. Plus its a synch to inject E85 through injectors. Water is what makes water injection so difficult. Special nozzle this special pump that. K.I.S.S.

E85 isnt blended to run leaner.. Ethanol itself does have a "richer" stoich ratio 9:1 vs 14.7:1. If you run Ethanol in a car tuned for 14.7:1 it will run leaner than intended for that fuel. If you aim closer to 9:1 with your tune than there is nothing lean about it. Which brings up the point of Octane. Ethanol requires more fuel to make the same amount of power (See Matt's numbers). More fuel equals more mass and more mass can absorb more heat energy. This ability to pull heat from the combustion chamber is the leading reason that Ethanol has a higher octane rating than gasoline.

Has anybody else noticed the Auto-Spell check feature? I just noticed it tonight.. wow.. neat. I have NO idea where that came from.

Old Colt · Post by **Old Colt** » Thu Dec 14, 2006 8:37 am

If ethanol and alcohols were inconsistent I doubt IRL would be going to 100% Ethanol, and NASCAR is also in talks to do the same in the near future.

Ahh but they do have big problems with inconsistency of the fuel. The teams inspect each barrel at the track, if a seal ring is even in question that barrel is moved aside and another selected. They open a barrel right before the fuel goes in a car, if the fuel is not used in that session the barrel is moved aside and a fresh one is put in Q for the next fill.
Ethanol absorbs moisture and gels. The amount of waste during there events is tremendous.

The street fuels also absorb moisture but is not monitored. This is why my comment that it goes off.

I was under the impression that E 85 was 15% ethanol, not 85%.
It is designed to lean an engine since it is an oxygen bearing fuel, it may take more fuel to reach stoich since it brings it's own oxygen to the mix.

For water injection we are mixing our own blend so water absorption is not the issue. Plus we can choose other alcohols to play with.

Coolingmist pumps are standard issue Sureflow pumps, nothing special, good stuff, I have a few of them.
There is nothing in the Coolingmist product line that will get this level of injection done that I know of unless they have something new in the last year or so.
Thinking a duty cycle input to these pumps can give you a controlled flow output will be a challenge. Good luck. It needs to be done just as a fuel injector, I am using a duty cycle controlled valve with controlled pressure from the pump. It still has not been just right yet.

Post by **DJpowerHaus** » Thu Dec 14, 2006 7:34 pm

I'm not too concerned about what NASCAR teams do with their fuel. These NASCAR teams have as close to unlimited budgets as you'll ever see. I'll just ask... what do they do with those "bad" barrels after the race?

Old Colt · Post by **Old Colt** » Thu Dec 14, 2006 7:56 pm

I was at NH Speedway during a test session, the fuel barrels get stored in our tech building. All the barrels get returned to the building part full or empty, the ones that the teams questioned never left the building. I expect the Texaco distributor fetches them all afterwards.

I have not seen the E 85 fuel up here, I expect it is a regional distribution, I have heard of it but as I said, I have no experiance with it.

Bill Hincher · Post by **Bill Hincher** » Fri Dec 15, 2006 8:44 am

We have had a lot of problems with fuel blends here, the problems include how easy the ethynol and methonal fuels collect water from humidity and from the underground tanks at the gas stations. They also clean the inside of storage tanks and collect a ' scale' that it brings up from old tanks and get into the cars.
The boiling point of these fuels is much lower that gasoline, when under hood temps raise, it boils in the fuel lines before reaching the injectors. This problem was much more evident in carburated cars.
Winter mix has always been different from summer mix and denser fuels always release more BTU's
When you start throwing around numbers on what to 02 senser sees as stoich, you are tampering with federal regulations, I assure you that the engineers will not put a fuel on the open market that alters the federal regs
Those tanks of fuel from testing go out the door with tires, when a rain out occurs at a nascar race, the teams loose all the tires they tested for that day and its VERY expensive. they just go to the junk!

sportd-fifty · Post by **sportd-fifty** » Fri Dec 15, 2006 2:08 pm

I dont know if im cutting into the middle of this but theres a guy that has a mockup design of water alcohol injection on his website. www.turbomirage.com Isnt that one of yous guys here?

Robert Venable · Post by **Robert Venable** » Sat Dec 16, 2006 1:29 am

Matt, I think you left a few things out:

The boiling point of pure liquid ethanol under 45psi of pressure is 110*C at sea level, and that temperature increases as you go up in altitude. If your fuel is reaching 110*C you've got other problems to deal with!!! Ethanol's boiling point

Whats after this?

However on a low pressure carbureted setup (10psi we'll say) the boiling point is

And this?

tonydanzah · Post by **tonydanzah** » Sun Jan 28, 2007 6:03 pm

Water injection links

www.aquamist.co.uk

www.rallycars.com/Cars/WaterInjection.html

http://www.dawesdevices.com/water.html

http://www.hackaday.com/2005/06/25/home ... injection/

77amc · Post by **77amc** » Tue Sep 30, 2008 9:35 pm

ZEX used to make a secondary type of injection 'thingy' that you just put the 'normal' injector through it and bolt it down to your fuel rail.
I think COMP CAMS bought them out. It's in the back of thier catalog.
Kinda pricey though. about 100/ea.

E