Water Injection?

[Delta Flyer]

Maybe I'm becoming less skeptical about water injection. A couple of times just after a rain, the fuel economy seemed to increase about 10%. Anyone else experience this?

It tempts me to want to put a fine mister in the air intake. I still hesitate to meddle with the engine any more than that.

Hi Delta_Flyer:

___About 30 years ago, some were actually selling kits for carbureted ICE’s to do exactly that. It was mostly a hoax way back when but I too have seen a 10 - 20 mpg rise when traversing light fog at cruise and as soon as it cleared, the mileage went back to a normal 105 - 110. This happened about 4 weeks ago on I55 South of Joliet and only lasted for about 3 or 4 minutes unfortunately … There is something to it but I don’t know what it is given I have driven in rain, before rain, after rain, through high and low humidity conditions and in all cases I haven’t seen a large increase like I saw when traversing that light fog bank.

___Good Luck

___Wayne R. Gerdes
___Hunt Club Farms Landscaping Ltd.
___[email:2gqe8ogp]Waynegerdes@earthlink.net[/email:2gqe8ogp]

[flunkysama]

Water injection is primarily done to prevent knocking. It does this by cooling the incoming air and soaking up combustion heat when it turns to steam. By itself, it usually does not improve efficency/HP.

[Yves M.]

(Sorry if I already wrote about this in a previous tread)

My knowledge is that the water cools the combustion. Water evaporation needs energy and it cools the burning process in the cylinder. This helps the ECM to add more ignition timming (less knock).

I tried that more about 20 years ago to make a V8 racing engine (high compression) run on 87 normal octane fuel. And it worked really well, than Firebird was really cool:
low ratio differential for best MPG, automatic transmission and the tires would spin shifting from 1st to 2nd gear at 60 MPH

In the long run, I experienced rust on the engine parts (everything was steel back then) and more in the exhaust. There was no catalyser on the car back then, I do not know if the catalysers and exhauts sensors will like the idea much, over time.

EDIT:Sorry flunkysama, we wrote at the same time

Hi Flunkysama and Yves:

___Water and Ethanol injection for cooling the intake charge to reduce knock has been used for well over 60 years now. Many WWII fighters had this capability and you dialed it in manually as needed for more performance over a short period of time.

___What we are discussing is that in some fogs or higher humidity conditions, there is an affect that does in fact increase mileage by a rather large percentage and it is worth talking about. This isn’t just timing advance for maximum performance or fuel economy, nor is it cooling the charge for an anti-knock prep thus leaving timing fully advanced under WOT. I just don’t know anything about the physics of the phenomena nor do I know anyone that has really done the work to make it a viable product for any of us and our automobiles.

___As for rust in the exhaust, much of an ICE’s effluent is already water vapor …

___Good Luck

___Wayne R. Gerdes
___Hunt Club Farms Landscaping Ltd.
___[email:2gydddjj]Waynegerdes@earthlink.net[/email:2gydddjj]

[Delta Flyer]

I've seen a number of companies trying to sell water injectors. It seems like someone would have just devised a fogger and just splice it into the air intake. Why make it major surgery?

What little I know on this topic is water injection benefits high compression engines such as the Insight the most.

I guess this idea will have to be shelved...

[fscott]

Originally Posted by xcel

Hi Flunkysama and Yves:
___As for rust in the exhaust, much of an ICE’s effluent is already water vapor …

It's not so much rust in the exhaust as it is rust on the head, valves, piston, rings...
Racers use water injection because they tear down their motor every race. There's no way I'd put it on my daily driver.

Fred

Hi Fscott:

___It isn’t the rust on the heads and pistons (Insight’s pistons, cylinder, and head are aluminum alloys) and such (valves are probably a high strength steel) that many here would worry about with a proper fog fuel mixture, it is the actual fuel economy. Racers run advanced timing and can use a higher octane fuel or some type of coolant (water or ethanol injection) to prevent pre-detonation for higher HP just as they use Cold Air Intakes for a higher density fuel air charge for more HP. Fuel economy drivers most certainly don’t want a cold air charge for more HP but want a warm air charge for a more efficient burn of the fuel air mixture which results in higher fuel economy. Hence the warm air intake mods. The high humidity fuel economy increase does not come about from any timing advance trickery. It is some type of RH/fuel/air mixture ratio that brings about a nice % increase in fuel economy. This increased fuel economy doesn’t happen whenever you drive through any fog bank or after every rain. If this perfect mixture was discovered, you might have a chance of duplicating it with a fog type device on the intake but only if it could be controlled to maintain this perfect mixture throughout much of an Insight’ers driving envelope. A S/D of the fog mixture device below a certain RPM would probably remedy any of your rust concerns.

___Again, I don’t know what the exact parameters that cause the fuel economy increase in high humidity conditions to appear but I have seen it with my own game gauge. With that, it does not come about from advanced timing but somehow a much more efficient fuel air mixture burn because of the increased amount of water vapor (proper amount of H2O at probably in a particular temperature band probably?) in the fuel air mix.

___Believe me that I am speaking well beyond my knowledge of the fuel air mixture creation and burn cycle here so take my comments for what they are worth. Quite a bit less then $0.02 in fact

___Good Luck

___Wayne R. Gerdes
___Hunt Club Farms Landscaping Ltd.
___[email:3i7llg67]Waynegerdes@earthlink.net[/email:3i7llg67]

[Yves M.]

About ignition timming and cold air: my 2 cents

Timming:
=======
More advance timming improves efficiency. The purpose is to get the best punch on the piston top (at the right time). It improves HP for those who need it but in fact, it takes for the same power: less fuel (better MPG)
It is standard to try to put more timming (the reason for the knock sensor) . A good portion of the 114 octane race fuel addition in horsepower comes from the more ignition timming it allows.
But remember that timming is improving efficiency. Efficiency is better MPG


Honda's preprogrammed fuel injection:
=========================
For the Warm air mod, I do not beleive that it is related directly to the air temp and combustion.
For example, that thing existed for carburator cars. But the only reason was because at freezing temp and a little above, the ventury inside the carb (which causes air acceleration and therefore a vacum and a drop in air tempature) would accumulate ice due to the humidity in the air, and would freeze closed. The car would buck and stop. You would then let the engine warm up the carb naturally and you would drive again.
At lower than freezing, there is less humidity and the carb did not need the hot air anymore.
Fuel injection is not affected by the problem encountered by ventury (carb)

I am absolutly sure that the only reason the warm air mod gives better MPG is because of Honda's programmation for the fuel injection. They have used a program (responding to sensors) that gives much more fuel than needed for a particular cold air temp. You basically fool the computer into thinking that the temp is higher and it gives the Honda preprogrammed fuel for it. In the same direction, It could give you lean burn in environment where you would not have had it.
This is not combustion efficiency difference between using cold or hot air.

Last:
===
I think that we need to foresee what has Honda done in the car to comprehend how the environment modifies the MPG.

I have experienced it in the past with my car and the exhaust system lasting about 25% the life of the non-humid ones. I would not augment the humidity level for my catalyer$$$, sensor$$ and muffler$ even knowing that the tubes are stainless.

I agree with Fred, "There's no way I'd put it on my daily driver"
I do not know the % chance to have rust particules score my engine's cylinders and pistons. If it was that easy to do, car manufactures would have used it a few decades ago.

Again these are my 2 cents from my knowledge. I could be wrong but I do not forsee a reason.

Hi Yves:

___But …

1. The Insight’s timing can only be advanced so far before knock or an exploding crankshaft.

2. The Insight at steady cruise through a fog type environment has shown a 15 - 20% increase for no other reason then the fog bank being driven through.

3. The Timing no matter what it was advanced or retarded to does not give a 15 - 20% increase in fuel economy at a steady cruise. Lean burn will but we are already in lean burn when the increase happens.

___This is why it isn’t about timing advance but something w/ the fuel air mixture and that excess H2O vapor. I don’t know what it is but it definitely isn’t in the timing or we would see the improved fuel economy when the timing changes, not when driving through a particular fog bank at a particular temperature.

___As for an increase in HP and fuel economy, something doesn’t add up in regards to our Insight’s. Whether that is the Fuel map or whatever, use a CAI in temps below 70 degrees and your fuel economy in an Insight will fall. Use a CAI in any std. ICE and the fuel economy falls as temps fall as well. The MDX’s fuel economy at ~ 55 degrees F and below drops by ~ 15%. You can see this on the game gauge. The Corolla drops around 10% below ~ 55 degrees F and another 10% below ~ 32 degrees. I don’t really care what HP is doing but if CAI’s worked to improve it, great. In terms of fuel economy in my experience with the Corolla, MDX, and Insight, the colder the AIT, the lower the fuel economy.

___Good Luck

___Wayne R. Gerdes
___Hunt Club Farms Landscaping Ltd.
___[email:67lyesbn]Waynegerdes@earthlink.net[/email:67lyesbn]