LUV94RX7

iTrader: (3)

Ya, I know, another nutty idea by Ken.

I’ve been e-mailing back and forth with my Aquamist guy in England. We have come to the conclusion that for every 10 degrees F we can drop the intake air mixture we can gain up to 2% power improvement assuming we fiddle with the ignition timing properly. We also figure there is an optimum low air temp intake for the best results. I am assuming that is about 40 degrees F. Maybe I’m wrong.

Now there was a case study of a car running 22psi and his intake air temp dropped another 60 degrees F with the proper amount of water injected. It still was about 108 degrees F. Now I want to be able to under race conditions lower it as close to 40 degrees F. Those 60+ degrees lower temps will buy me lots of power.

Now here’s my idea. I bounced it off the Aquamist guy and he said make sure the input water temps do not freeze. That’s no problem as I can use windshield washer solution that is good for very low temps –25 degrees F added to my water tank(3 gallon fuel cell). I want to put together some kind of an insulated tank that I can pour –10 degrees F windshield washer solution into it. I’ll get this solution cooled down in my freezer at home. The tank needs to be able to have this cold solution poured into it easily and when it gets warm, poured out and re-cooled in my freezer. Be able to easy fill and easy empty. I want to have it surround the last part of the tubes going into my intake just after the intercooler exit. Aquamist guy recommended loops of copper coils at the end to absorb the cold solution to the water injection solution.

With such a device I should be able to get down to 40 degrees F even under high boost (22psi) and high rpms.

Any ideas out there on such a tank type device?

If I’m right and he thinks I am, I will be running very cool intake air temps and the idea might be worth an easy 10+% power improvement. I am willing to go thru this hassle for the extra power in race conditions.

Thanx for any ideas.

Ken

RICE RACING

Ken, I ran 1.5 bar for the past 3 days with a water flow rate of 270 to 280ml/min ...straight water.

Did this with 98octane unleaded B11EGV plugs and 12deg spark advance at full power condition.

My air flow rate throught the engine is about 29kg/min with this PR and my engine set up. I am using 3.25lt/min of fuel at full power. I am not getting any detonation or any sign of pinging at all.

My charge temp at 8deg C day is around 15 deg C in the IC outlet pipe (checked this today) All up eff = 94% without the water injection my IC gets around 89%. I just thought I would share my result, your idea has merit however what I have found is that you will want to insulate the line all the way to the nozzel injection point and also the nozzle as well because the flow rate of water is not so high and you will find by the time it travels along the line and out the nozzel that it is very near the temp local to the nozzel discharge. I would simply instead of lowering the temperature of the liquid simply increase the amount injected to get the same result IE much lower charge temp. Did you know that some aviation engines inject up too 25% water realative to the fuel injected

Just make sure you run a good strong spark ! I have had no problems since my CDI upgrade.

regards.

Peter.

PS my results are a bit different to aquamists as I inject infront of the turbo, on paper it is not as good however I have tried both methods and got more consistent gains injecting there instead of in the induction pipe. I use a special water atomising nozzle that mixes the water with high pressure air from the turbo to atomize the water so it does not cause wear on the compressor wheel. Both methods work.

LUV94RX7

iTrader: (3)

I told Dave at KDR to insulate the line from my 3 gallon fuel cell in the back of my car. I hope he did, else I will. Thanks for the idea of insulating the nozzle, I never thought of that. I have nozzles for up to 320ml/min of water with 3d mapping. I was figuring about 10% water to fuel ratio. Hopefully Dave will be able to figure out all the water flows per boost and rpm ranges. Aquamist says put the most water at the highest torque point -that is where detonation is most critical. I'll pass your post onto him.

What are your feelings for the optimum intake air temp to get the most power - 4C??

Also our estimate of up to 2% power gain for every 5C cooler the intake charge is?

I will be using a Power FC if I can ever get one delivered.

Here's my configuration:
mods: Street port & polished stage II, 3mm Hurley racing seals, upgraded coolant seals, Power FC ecu, XS T04e single turbo kit, SMIC (400+cu.in.), Aquamist 2s water injection kit, Pettit ss resonated MP, Pettit ss cat-back, RP Racing fuel pump, 1600cc injectors, Profec B(12&22psi), under pulley kit(no air pump), Evans Coolant

I'm figuring water will help me reach my power goals.
I'm guessing a peak of 360rwhp at 12psi and 460rwhp at 22psi. Do you have any thoughts on my guesses.

Thanx again

Ken

crispeed

Peter!
Now that we're on the topic of water injection I've been meaning to ask what would be difference or actual temperature reduction of injecting water into a setup with very high air tems vs one with lower temps? Basically if you were to inject the same amount of water which setup would actually have the greater temperature drop. The reason for me asking was because a lot of people I know claimed in their experience that in a well designed Intercooled system the hassle is not worth the effort.
I personaly have seen the difference in what lower air temps can yield in both power and reliability!
So what's the deal with that special nozzle you're using? Injecting into the turbo inlet would sure make it much easier in setup design but I've always heard and seen from other racers the problem of compressor wheel erosion.

crispeed
87 Rx-7 TII
9.204@150.47mph
2600lbs
ub-tubbed

LUV94RX7

iTrader: (3)

[QUOTE]Originally posted by RICE RACING
[B]Ken, I ran 1.5 bar for the past 3 days with a water flow rate of 270 to 280ml/min ...straight water.
Did this with 98octane unleaded B11EGV plugs and 12deg spark advance at full power condition.

Ken's comment,
I like the 98 octane, KDR was saying more like 110 octane at 1.5 bar.

My charge temp at 8deg C day is around 15 deg C in the IC outlet pipe (checked this today)

Ken's response,
It seems to me if the water you were injecting was 0deg C instead of greater than an 8deg C day your IC outlet temp would be lower than 15 deg C. To me that would be better than just injecting more water. Also if you mixted it with methanol you could get it lower than 0 deg C and really cool it down.

All up eff = 94% without the water injection my IC gets around 89%.

I did not understand this comment.

Ken

RICE RACING

My experience is that it is not so much the charge temp reduction but the influence of what happens in the combustion chamber (when it turns to steam) that has a benifit that I have not been able to explain, I think aquamist have dificulty with this as well ?

I remember when Ferrari were draged in front of the FIA back in 83 to explain why they should not ban water injection they "Ferrari" said there was no technical reason that showed how water or steam enhanced power by the amount that it did. It is not a pure function of charge temp reduction but a complex interaction of steam acting as a combustion stimulant ! yes a stimulant ! I do not have the ability to explain why this is so and infact many things contradict this (as to why I needed a CDI to get the WI full benifit) but I truley believe it to work and enhance reliability of ferrous based seals without question.

Now the nozzle I use is made by spraying systems USA SUE18A modified by me to get the flow I need, Chris you would need two of these depending on the boost you are using.

Ken with the WI my efficiency goes from 89% to 94% my charge temp with the WI is 15deg C without it it is 21degC on a 8deg C day on 21.75psi boost. Again I have been using 98 octane with no problem what so ever at this boost level with 200:1 premix and 12deg advance with no split with 11 heat range plugs.

On the question of potential benifit in a coolish charge temp (well IC engine?) well it is what happens in the chamber that is critical this is where I believe the water does its magical stuff (that has not much of a formal explination) It absorbs more "heat" than methanol per unit weight and allows more advanced settings to fuel and ignition than combinations of fluids, only issue is with freezing I guess?

I only realy jumped on the bandwagon with this technology once I found it was so popular in aviation from piston relics to current gas turbines, they key is the reduction in internal temperatures and turbine temperature allowing more boost more timing, more correct a/f ratio and higher power while using lower octane. Evil aviator may have more current information as to its applications in gas turbines but I know it is still in use today so planes can reliably increase there take off power without engine failure.

If you look at aquamists sight they have a good formula that ties in the air mass flow with water flow and the reduction of charge temp that the water will achieve "assuming it is fully evaporated" But yeah it is a great technology, I like it, almost as much as my engine does

RICE RACING

Ferrari actually used a technology developed by AGIP (petrol supplier) that encapsulated a droplet of fuel with a droplet of water, it was used in gas turbines at that time, so they were no seeing a drop in actual post IC charge temp but what happened in the cylinder instead.

It was called "emulstine" i think, it was fairly radical. Renault had a much more basic system like the aquamist one.

Very interesting stuff !

cach22

Rice:
So apart from the lower intake temps etc, what sort of power gains have you noticed?? Or is it more a case that cause the intake temps are lower etc that you can crank the boost up/advance the timming a bit more to gain more power?

Cheers

Lance

kristopher_d

Consider this. When water boils, it turns to steam, and that steam expands. The colder water requires more energy to boil. So, warmer water will boil sooner, and the resulting steam will have more energy to absorb causing it to expand with greater force. So it is likely a combination of combustion chamber temperature, pressure (also a factor in energy required to boil water), combustion rate, and overal temperature gain. The water cannot act as a stimulant for combustion, not under any conditions we are currently aware of. However, it can increase energy efficiancy by utilizing some of the heat that is normaly exhausted to create higher gas pressures inside the combustion chamber.

With no formal training this is merely backyard physics theory, though it seems completely logical. A major theme in Ayn Rands "Atlas Shrugged" is that when you wittness the impossible, you must check your bases,one of them is wrong.

airborne

Ken - i actually asked dave@kd about aquamist and he said he'd let me know when they tried it out! are you the guinea pig? how would the aquamist work as a kind of plug n' play mod? i'm hoping/guessing you'd see some good reliability benefits, but need serious tuning to realize the full potential of the system.

LUV94RX7

iTrader: (3)

Well, the 2s kit has 3d mapping which needs to be programmed and dyno tuned. I have that kit. The 1s kit is simple. You just pick an injector size and what boost level you want it to kick in and at that level and above it injects water solution at whatever volume the injector you selected injects at.

Ya, I know I'm the guinea pig. But once it's installed correctly I will post all kinds of performance data. I have an Omega guage and 4 air temp probes to measure air temps at the K&N filter, after the turbo, after the SMIC and after water injection. I can do this in all kinds of conditions to measure the value of water for cooling. It also is a giant benefit to being able to run higher boost safely without detonation.

Ken

LUV94RX7

iTrader: (3)

GMONSEN has the 2c kit which is able to be programmed from the Haltech ecu. Todate I do not believe he has installed it yet.

Ken

cymrex

iTrader: (2)

A few calculations of the affect:

Assumptions:
280 ml/min of Pure Water are being injected (to use RICE RACING's data)
The chiller would decrease the temp of the Pure Water to 0 C.
For comparison a worst case day of 50 C 122 F is the outside temperature and the water without the chiller would be that temperature.

Heat Water from 0 C to 50 C
Cp = 4.184 J/Gr-C
4.184 J * 280 Gr * 50 C = 58576 J
Gr-C Min Min

Heat Water from 50 C to 100 C
Cp = 4.184 J/Gr-C
4.184 J * 280 Gr * 50 C = 58576 J
Gr-C Min Min

Vaporise the liquid water 100 C liquid before 100 C vapor after
Heat of Vaporisation of water = 40700 J/Mol
Mass conversion for water = 18.0 Gr/Mol
40700 J * 1 Mol * 280 Gr = 633111 J
Mol 18.0 Gr Min Min

Heat Vapor from 100 C to 900 C
Cp = 2.02 J/Gr-C
2.02 J * 280 Gr * 800 C = 452480 J
Gr-C Min Min

Results
1144167 J Without the Chiller
Min

1202743 J With the Chiller
Min



This leads to the chilling system to get the water from 50 C to 0 C netting 58576 J/Min this is a 5% increase in energy absorbed by the water injection.

cymrex

iTrader: (2)

One thing I have seen drag racers use is a cool can to chill the fuel. If the water injection is 10% of the fuel need then cooling the fuel could be more effective since it has 10 times the volume.

In an article on water to air intercooling I saw the suggestion to use an alcohol and dry ice mixture to provide longer lasting lower than ambient intake temperatures. What do you think about chilling the fuel in the manner you are discussing with a alcohol and dry ice mixture in the insulated recepticle. Maybe some more calculations are in order.

LUV94RX7

iTrader: (3)

Very interesting post. Thank you very much. Isn't 50C = 132F?

I don't know what some of the elements mean in your formula (Cp, Gr-C, J, Mol, J.Min)

You can get the water to below 0C if you add methanol to it, like windshield washer fluid to -25 degrees F, If you put it in a home freezer it can be as low as -10 degrees F.

Thanx again,

Ken

LUV94RX7

iTrader: (3)

This leads to the chilling system to get the water from 50 C to 0 C netting 58576 J/Min this is a 5% increase in energy absorbed by the water injection.

What does this mean for me?
Please explain, I'm a novice.

Ken

LUV94RX7

iTrader: (3)

What if water injection was 320ml/min, my injector size, and water90%/methanol10% was -6C. What would that do to the numbers.

Thanx

Ken

LUV94RX7

iTrader: (3)

What do you think of this to cool the water injected into my aquamist injectors?

http://www.jegs.com/cgi-bin/ncommerc...16&prmenbr=361

It's 7.75x7.75x8" high.

Just pour minus 10 degrees F windshield washer fluid into it for racing situations. Then drain it out and re-freeze it in your home freezer. It has a drain **** at the bottom.

Ken

87GTR

iTrader: (61)

Im about to install a 2C system to use with Haltech if things go well im looking at running 23 - 24 # on 93 with ngk 11's.

the cooler tank looks like I good idea.

SPOautos

I wonder how windshield washer fluid will do to the combustion process??? What kind of affects do you think it will have???

BTW - speaking of the cool can for fuel, I met this guy at the track one day that ran about 5 runs in his car (old auto N/A muscle car), they were all VERY consistand 12.0's, filled his cool can full of ice and water waited about 10 minutes and with NO other changes ran consistant high 11.60's(almost 11.70's). I was very surprised, actually he was surprised too. It was on a test and tune night, he was there just trying to see how much difference he would get just from fuel cooling. All it consisted of was an ice bucket from a hotel room with a hole drilled on each side for his fuel line to run thru then some caulking around the hole so it didnt leak. Pretty damn cheap mod if you ask me haha I was kind of surprised that such a small bucket could cool the fuel fast enough. After feeling the line before and after the bucket, I noticed the ice was cooling the fuel line for about a 3 foot span which I guess was long enough to get the fuel cold.

STEPHEN

KevinK2

This nice analysis shows that most of the energy absorbed by the wi is due to the phase change of the water, and that the energy needed to heat cooler injected water is a small amount. The 5% improvement in heat removal with colder water will be hard to see on a dyno (like 5% improved IC).

Another way to look at it is mass flow. For 10% water inj vs fuel, and 11:1 air/fuel ratio, less than 1% of the mass fed into the combustion chambers is being directly pre chilled by just cooling the water. Some racers prechill the fuel, but u can see thats much more mass flow involved.

Best to spend some time optimizing the injector(s) locations to assure good uniform effect to all runners.

Aquamist water inj'n and high boost rotaries should be a very good combo, esp on a road-race track where SMIC's heatsoak, and FMIC's can tax even an upgraded rad.

rotard

I'm really new, and maybe way off base. But about cymrex's calculations, are 280 gs of pure water being injected? Isn't it 280 ml of mist? Does this have implications on the power gain?

88IntegraLS

That is my thinking on Water Injection, that it utilizes some of wasted heat energy of a rotary engine's exhaust. The headed water in the combustion chamber becomes expanding steam, converting exhaust gas heat into mechanical energy.

Maxthe7man

The most energy is absorbed when water terms to vapour(steam) which is 970 btu's/lb as opposed to 1btu/lb/degF for liquid, the thing to remember though as the pressure increases the vapourization point moves up with it, With Rice racing injecting it before the turbo, mostly likely he is boiling more of the water off and getting more heat removal because of the lower pressure area in front of the turbo.
For the guys with windshield washer fluid questions, I had a summer job once making that stuff, its 80% water, 18% methanol 2% dish detergent, and blue dye..
What happened to Kens propane experiments? enriching with propane, and using its latent heat of vapourization from a liquid to a gas to as a chemical supercharger, as well as its 100+ octane rating, and itself being a fuel seemed like a sure fire winner for high boost applications, the only thing is propane is starting to get stupid expensive for some reason..Max

Scalliwag

The cool cans have been around a long time. Ice, dry ice, and "bumping" it with alcohol has worked. I have wondered if you added a freon cannister with a jetted inlet using a solenoid so you could "spike" the hell out of it just before and during the runs how it would work.
It may lead to catastrophe, but that has never stopped anybody from trying