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86TSiGuy
09-26-2013, 09:25 PM
I don't know if anybody else is interested but I thought I'd post this in case there is.

It's a spreadsheet calculator that determines actual IAT reductions based on injecting water-methanol with or without an intercooler.
The model is based on an adiabatic equlibrium, if anybody wants there is a write-up on the math's as well.

Not sure how to post an excel file so I'm linking it from my google drive.

Cheers,...

https://docs.google.com/spreadsheet/ccc?key=0As9xZr1WAImpdFAwaWN2SDNvcGpqekVWMjNIeGxyY 2c&usp=sharing

86TSiGuy
10-02-2013, 04:19 PM
Revised. Enter variables in grey, get results in orange. V3 now takes into account the air charge shrinking as it cools. Can be used to find compressor outlet temps or effect of humidity also. Works for all gas 4-stroke engines turbo, super, or NA. Much more accurate than vendor offerings.

wallace
12-20-2013, 09:27 AM
Says you need access to view. I submitted a request for access. Are you the admin?

86TSiGuy
12-20-2013, 10:46 AM
Says you need access to view. I submitted a request for access. Are you the admin?

Opened it up for you...

86TSiGuy
12-20-2013, 11:23 AM
Inputs:

% weight meth = methanol content of injection fluid 0.0-1.0
Corrected Flow Rate = actual injection rate based on size and number of jets, as well as pump pressure in gph.
Engine Volume = self explanatory, litres only.
Engine rpm = also self explanatory, try calculating lowest rpm of injection through redline.
Manifold Pressure = boost pressure in psig, do not include ATM. pressure.
Ambient Air Temp = fairly straightforward.
Ambient Air Pressure = also fairly straightforward, I use the weather channel site for current info.
Relative humidity = this has a surprisingly large effect, again weather channel for cu4rent info 0.0-1.0.
Compressor Inlet Increase = This is the difference in temp between ambient and under hood, if you have a true cold air intake this may be as little as 1-2 degrees, or as much as 10-15 if your sucking hot under hood air.
Compressor Efficiency = this is the efficiency of the turbo/supercharger at the specified boost pressure, remember your compressor may not be at peak island efficiency at the boost you've selected.

Intercooler efficiency = if you have one, currently the calc assumes fluid is injected before the intercooler, the next revision will allow you to specify.
Fuel air target= this is the AFR your ECU is trying to achieve before fluid injection.

86TSiGuy
12-20-2013, 12:13 PM
Outputs:

Compressor outlet temp = this is before inter cooling or fluid injection.
Temp after water-meth = self explanatory.
Temp after cooler = this is final charge temp after fluid and cooler.
Efficiency of water-meth = this is pretty intercooler temp drop efficiency.
Total IAT drop = degrees Celsius removed from intake charge total.
Fuel mass = mass of gasoline required to meet to target AFR at given volume, rpm, and AFR target.
Fluid to Fuel ratio = this is the ratio of water-meth injected relative to fuel.
Fluid to air ratio = this is the ratio of fluid injected relative to mass of air in system.
End AFR with water-meth = this is your resulting AFR after injection, this is especially important for tuning water-meth.
AFR reduction = this is how much your AFR will drop under injection.
% density lost to fluid = this is the percentage of overall charge density lost to fluid occupation. Or percentage power lost due to water taking the place of air in the intake charge.
Final RH = this was a new output the last update, it represents the new relative humidity of the intake charge. This is extremely useful for determining when too much is too much. A relative humidity of 80% or more indicates the possibility that not all of the fluid will be vaporized prior to compression.
Net density change = this is the net gain or loss of charge density, it can be taken as a relative percentage increase or decrease of power relative to the engine operating under the same conditions but without fluid injection.
Final compressor efficiency = also new for latest revision this is an estimate of the compressor efficiency if fluid is injected pre-compressor, this output may have a bug somewhere I need to integrate more data and recompile.
Efficiency delta = this is based upon the above efficiency gain and therefore may also be flawed. In theory it represents the percentage gain in efficiency of the compressor if fluid is injected before.

zin
12-20-2013, 01:01 PM
Do you happen to know if the results would be similar if a different alcohol was used? ,say Iso, or ethanol...

Mike

johnl
12-20-2013, 01:23 PM
Great post, thanks.

86TSiGuy
12-20-2013, 02:16 PM
Do you happen to know if the results would be similar if a different alcohol was used? ,say Iso, or ethanol...

Mike

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Do you happen to know if the results would be similar if a different alcohol was used? ,say Iso, or ethanol...

Mike

Similar but not identical, both isopropynol and ethanol have different molar weights and enthalpies. Ethanol has a greater calorific value than methanol and iso much less.

It is possible to tailor the calc to either by swapping values in the data pool for those of the desired fuel.

Because of the drastic differences in surface energy I would not use iso for pre-compressor injection, ethanol would actually work better but will produce a greater drop in AFR while achieving no significant gain over methanol in temp drops.

What were you considering using?

Reaper1
12-20-2013, 02:57 PM
Subscribed! I want to mess with this more when I get home.

zin
12-20-2013, 10:33 PM
Similar but not identical, both isopropynol and ethanol have different molar weights and enthalpies. Ethanol has a greater calorific value than methanol and iso much less.

It is possible to tailor the calc to either by swapping values in the data pool for those of the desired fuel.

Because of the drastic differences in surface energy I would not use iso for pre-compressor injection, ethanol would actually work better but will produce a greater drop in AFR while achieving no significant gain over methanol in temp drops.

What were you considering using?

Really just considering the "what ifs", like if I run out of one, can I run into a drugstore and get whatever is available, and still know how much I'd have to compensate.

What I'm considering most right now is denatured alcohol, as it's available almost everywhere and seems like a good choice performance-wise.

Mike

86TSiGuy
12-20-2013, 10:49 PM
Really just considering the "what ifs", like if I run out of one, can I run into a drugstore and get whatever is available, and still know how much I'd have to compensate.

What I'm considering most right now is denatured alcohol, as it's available almost everywhere and seems like a good choice performance-wise.

Mike

denatured alcohol is mostly ethanol, in the us it must be at least 90% ethanol in fact. The other 10% is mostly methanol with a little tolulene, etc.

if you were to tune for ethanol fluid, I don't believe the slight difference between ethanol and methanol would have significant impact at a 10% scale.

I buy methyl hydrate and mix it by weight with distilled water, its really cheap and readily available here. Also a decent sized tank lasts quite awhile under daily driving conditions, and of course if I personally ran out I would just disarm the injection system by switch until I could fill it up.

Ideally though with our cars 2.2\2.5 fluid injection should only be used for track or wot purposes because our computers lack the ability to to pull fuel and add timing only under injection.

Reaper1
12-21-2013, 01:04 AM
I understand that water does not burn, but it does vaporize and turn to steam which makes a LOT of pressure. Given that the combustion event still happens and is nearly a homogeneous charge, it is totally possible for water injection to make power even though fuel is being displaced. On the note of fuel being displaced, I'm not 100% convinced that happens. The injectors don't know or care that there is another fluid being introduced into the charge. They still will stay open and inject the same amount of fuel as if the water wasn't there.

Not that we could do it with the way our engines are set up, but in theory it is possible to get an internal combustion engine to run on just water. To my knowledge this is only theory and has not been accomplished.

As for not using alternative fluid injection in situations besides WOT or track use, I don't agree with that at all. Using it prevents part throttle, high load knock, plus it has the advantage of keeping temperatures in check. The caveat to that is that the injection can't be an on/off switch. It has to be progressive just the same as your fueling is.

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Access requested, please! :)

Aries_Turbo
12-21-2013, 09:38 AM
i requested access too

86TSiGuy
12-21-2013, 02:30 PM
I understand that water does not burn, but it does vaporize and turn to steam which makes a LOT of pressure. Given that the combustion event still happens and is nearly a homogeneous charge, it is totally possible for water injection to make power even though fuel is being displaced. On the note of fuel being displaced, I'm not 100% convinced that happens. The injectors don't know or care that there is another fluid being introduced into the charge. They still will stay open and inject the same amount of fuel as if the water wasn't there.

This is correct; injection fluid does not displace fuel. It does displace air however. The original purpose to the model was to determine a relationship between the amount of fluid (based on composition) injected and the resulting drop in the air fuel ratio. This is further complicated by the thermal effect of the fluid on the air charge. As the air cools it becomes denser. The output for % density lost tells you how much air you've displaced as a function of density. The output net density gain tells you whether the fluid cooling the air charge and increasing density outweighs the density lost due to displacement. In almost all cases there is a net gain.


Not that we could do it with the way our engines are set up, but in theory it is possible to get an internal combustion engine to run on just water. To my knowledge this is only theory and has not been accomplished.

This too is correct; a steam engine in either carnot or rankin cycle essentially runs on water vapor expansion.


As for not using alternative fluid injection in situations besides WOT or track use, I don't agree with that at all. Using it prevents part throttle, high load knock, plus it has the advantage of keeping temperatures in check. The caveat to that is that the injection can't be an on/off switch. It has to be progressive just the same as your fueling is.

To each his own, each application is different. In my personal experience the fuel and spark control MUST adapt to fluid being ON or the net gain is wiped out completely by the lack of advance and rich condition. A variation of more than a third of a point (0.33) begins to drastically reduce power. The only exception to this that I have found is a diesel engine, mostly due to it's nature.

Also, I know progressive controllers are the rage right now but in my personal experience I would not suggest them. I dislike the duty cycle grounding of the pump to produce intermediate pressure levels. Each injector produces a different flow and spray pattern at different pressures. Reducing the pressure to achieve a progressive flow weakens the fan pattern and atomization of the fluid. The atomization is integral to the process of equilibrium as it is mostly dependent on droplet size, surface energy, and shear forces. However I'm glad your having good luck.

All requests responded to. If a cell gets copied over or the formula broken it may take me a day to correct it. Hang in there. When I'm done with the next update I will lock the cells and make it available offline so everyone can keep their own copy.

I'm glad someone besides myself enjoyed it.

Cheers...

Aries_Turbo
12-21-2013, 09:53 PM
progressives IMHO are just so you dont get that wallop of water/alcohol as the boost rises which can make a car bog slightly as a solenoid opens.

thanks for the access. :)

Brian

wallace
12-23-2013, 08:16 AM
for those of you who are currently running water or a mixture of water/meth what size nozzle are you using and at what pressure?

86TSiGuy
12-23-2013, 09:40 AM
for those of you who are currently running water or a mixture of water/meth what size nozzle are you using and at what pressure?

250psi at the pump, -5 psi head loss = 245psi plus or minus vacuum at the injector

I've run 1,2, and 3gph at that pressure for 1.43-3.4 gph total.

The log motor could take nearly 1gph at idle without an intercooler without stalling.

I've also run a .5gph and 1 gph pre-compressor.

Reaper1
12-23-2013, 06:59 PM
for those of you who are currently running water or a mixture of water/meth what size nozzle are you using and at what pressure?

I'm running a progressive Devil's Own. I can't remember the jet size off the top of my head.

Ondonti
01-01-2014, 09:57 AM
The water in the mix issue makes a difference when you compare setups. Some people spray 3gph, some people like me spray 30+gph of 100% methanol. That causes spark blowout issues and I think if 15+gph of that was water, it would hurt power significantly. I know a lot of successful cars that have run these huge shots (not just diesels).

Here is how much ~30gph (really unknown since I have no verification of actual nozzle pressure on the 1.8gpm pump which is no longer sold by anyone I know, they all sell the 1.0gpm) changes AFR.
This is progressive devils own and should be turning on around 7-9psi (3500 rpms) and full on around 13-15psi (based on memory). Boost rises so quick the progressive nature of the devilsown setup simply blends in the fueling change. If you are running the max set point near your peak boost that would make things different. I have my doubts how much difference a small nozzle makes, especially when its mostly water.
http://i546.photobucket.com/albums/hh426/ondonti/No%20racing%20tonight/run4c.jpg

If all you are concerned about is WOT performance then a progressive is easy to handle. I pulled back fuel and relied on methanol to do the rest. Since I had my lower set point below 10psi I already had methanol cooling things down when boost increased and timing could have been considered excessive. I feel that is the whole point of the progressive setup, to start cooling things down early without overdoing it. In reality if your max set point is below your peak boost then you really see very little progressive action. When you have no fueling control you could lean out things by increasing the max setting on your methanol.

The combustion quality difference caused by not getting minimum droplet size seems like it would be very small to me having at one point put more methanol into my engine then gasoline while in boost. I seemed to have no ill effects as long as I had enough spark energy to light the plugs. I had to regap plugs on these dynos because the first pulls were misfiring from that methanol. If you are so worried about droplet size then I think thats also an indicator that you are worried about water hurting combustion, something I just have not seen with 100% methanol. There is no way those big nozzles give small droplet size, especially with how they should drop actual line pressures compared to a tiny nozzle. I don't know why someone would run their methanol nozzle at less then 100% duty cycle long term since you should just decrease your injector size OR remove factory fueling so you can run your pump 100% duty cycle. During the tuning process of increasing boost, doing pulls to check tune, and adjusting...you might not have your duty cycle maxed out, but once you get where you want to stay you should be either 100% duty @ max boost or in the process of purchasing the correct size nozzle or removing fuel from your tune.

I do like the progressive setup for the fact that if you want to play with some things, you can. It made a lot of sense in a world without full blown aftermarket ECU control. I do think it makes the transition point easier to tune. Progressive controllers mean you can blend transition points where a full on setup requires exacting changes in fueling/timing the moment the system activates which probably means you have to change fueling BEFORE activation and timing AFTER activation. That seems overly complicated but would be required in a max effort setup. Any less and you open yourself to windows where you have the wrong fueling or timing because the nozzles did not spray when your ECU was pretuned to compensate.

Reaper1
01-01-2014, 06:12 PM
For reference I used my progressive set-up more for insurance against crap gasoline and better intake charge cooling.

I can't confirm how well it worked for the first part of that other than the bottom end of the engine had over 200,000+ miles on it and I ran it at 22#'s for SEVERAL years even at road course track day events and never had a problem. I think it finally popped the head gasket because I was beating on it pretty hard and it got a little hot (not pegged). I never heard detonation, but with my Shel-Game cal with the CEL knock detection it would light the CEL up almost as soon as it hit boost, regardless of whether the water/meth injection was on, or what I had it set at. We figured it was a defective knock sensor, but I never got around to replacing it.

Now, as for keeping the intake charge cool, this I can 100%, without a doubt, confirm! At track day events I ALWAYS ran the injection. As soon as the session was over, I'd get to the paddock and pop the hood and there was condensation on the intake manifold! Also, the engine NEVER got hot on track. I have my doubts as to whether the stock cooling system would have been able to keep up, even with the large oil cooler I run.

I will also say that when I had the car on the dyno I tried running it with and without the injection turned on. It made NO difference in power or torque. I attribute this to the fact that I wasn't taking full advantage of the system. Plus, IF the engine was knocking (inaudible), it would have been pulling timing regardless of whether the system was on or not. I never saw any "salt & pepper" on my plugs, but one of the pistons did show minor signs of detonation, but it wasn't pitted much, more like rough to the touch.

I always set my system to come on around 10-14#'s and fully on at 18-20#'s. Of course at WOT that delay was not very long at all, but I have a feeling that it did help under part throttle, high load, high(er) boost. That is where a lot of my concern was as that is a recipe for blown up engines! Right, Brent? ;) (just messing with ya: nudge nudge)