I know they do this on many highly tuned fd's, but has anyone thought about doing it for an NA? I was going to make a radiator sprayer, a'la intercooler sprayer-style, but this may be more viable.

Anyone?

my flame-suit is ready, by the way...

 

What would be the advantage? Water injection is there to allow for leaner mixtures under boost. I cant imagine it would be advantageous...

 

i thought it was also for cooling the intake charge some.

 

Some old turboprop planes I used to work on used a water and methanol mixture for injection on takeoff on really hot days for more power, but that was takeoff power only (***** to the wall). If it's advantageous at all for an n/a, it would be in the max power range like that, I would think. The amount it would take to drop the air temps to the point that you're actually seeing viable power gains is another issue...

 

It also helps slow the combustion slightly, and does some other interesting things in the process.

What about using water injection combined with a leaner mixture? Water is cheap. Gas isn't. Lean the crap out of the engine at highway speeds & add water to prevent detonation.

-=Russ=-

 

It seems that people love to go around talking about detonation this, detonation that, without knowing what it is really about. Folks, detonation can only happen under considerable load. IT can't happen while idling, or even while free-revving. It can't happen at cruise either...unless the engine is under a fair amount of load, such as a hill climb, or moderate acceleration. This assumes you're not running some kind of radical timing advance.

I'll give to distinct examples for clarification.

1) your engine is sitting and idling, or for that matter cruising lightly along a flat stretch at less than 1/4 throttle. You have an safc, haltech, fuel pump voltage adjustment, etc. as a method to take away fuel. So the engine is running along, and you lean out the mix more and more. Does the engine detonate and blow up? No. IT runs out of fuel, misfires, and gradually stalls. You just took away it's fuel, and it could no longer combust...there wasn't enough heat and load involved to make conditions for detonation.

2) You're going WOT up a big hill on a hot day, with low octane gas and perhaps even some boost. You take away fuel, and you'll make conditions favorable for detonation. Even if you don't blow it up, you'll likely cause a few pings, at least. For anyone with an old chevy truck or a similar daily driver, the rattling you hear when under heavy load using low octane is actually light detonation.

Using water injection on a street tuned nonturbo would be wasteful...of time, and power. You can lean out an NA engine for cruising and never cause detonation, except perhaps hill climbing or the like. Even at WOT with a modded NA and 15* of timing advance, it's hard to induce detonation. That would be the only time water injection would be useful.

 

You've earned best post of the day.

 

what about the advantage of having your engine constantly steam cleaned?

 

Steam cleaning is good. However, power loss and misfiring are not. IN fact, if you ran water injection all the time, you'd lose quite a bit of power more than likely. For one, water does not combust, so it's taking up the space in the intake charge that could otherwise be occupied by oxygen or fuel, which do combust (and make power). IF you want a clean engine, run premix and do the water injection treatment in your driveway once a month. That thing would stay almost squeaky clean inside.

 

That made me laugh!

 

This brings up something interesting for the SC and Turbo guys. The SC modders have almost nil work room for an intercooler... would water injection be a possible answer?

 

Yes, water injection (setup properly) is sometimes used in leiu of an intercooler, or to help support it. The main issue is the quality of the injection control system (just as with fuel).

 

very interesting!

 

My dad used to run water injection on his fiat 124 spider, he had increased timming and i think shaved the head? the water stopped it from pining on regular fuel. It also makes the motor look like new inside with little or no carbon on teardown,..still besides the cleaning i dont think a NA rotary would benifit really..

 

I run it on my FC. Aquamist 2D. Comes on at 10 PSI and continues to spray until I let off.
I boost to 21 PSI on pump gas with it.
Don't see how there would be any advantage to running it on a NA.

 

Water injection on a N/A? GREAT IDEA if you want to make less power, dilute your oiling system, add complexity, have ineffient combustion, and go through the hastle of always having to fill up with not only gas (or pre-mix) but water too. Water injection takes away quite a bit of power. Also, N/A cars are very detonation resistant, even a street tuned 200 hp N/A can take quite a bit of hard knocks without any ill effects. I've seen MANY N/A's knock BAD due to wrong ignition timing and some with heavy carbon build up on the plugs. Its when your cramming large amounts of fuel and air (turbo / supercharger) is when your seeing BIG combustion pressures when detonation can blow a motor. Turbo or super charged... YES... N/A.. NO, its up there with the cat airpump supercharger idea.


~Mike........................

 

lol. well, when you put it like that...

 

Many of them FD guys run water injection, it's expensive do to the right way.

 

Hey, shut up!

 

heh, let it go-- I don't think it was a blatant blow at your ego-- at least not this time

 

well, i was just running the idea around in the empty space called my head.

now i know

 

I can't believe u people don't realize how hot the lower intake manifold of an NA or turbo II gets, hot day or not. It is right above the header or exhaust manifold and there is considerable heat absorbed by it through conduction and radiation off the exhaust manifold. Water injection upstream of the lower intake manifold will coat the manifold in the process of being ingested and cool it. The manifold can absorb and store considerable heat which gets conducted to the incoming air. Everyone knows hot air is not as dense as cold air for a given volume and pressure.

To those of u stating that water injection is worthless on an NA, just how fast did you get ur own NA's before giving up and going turbo? Lack of creativity = turn up the boost on this board, like always.

I'll have quarter mile times before / after my own na water injection experiment. All this debate without data is like watching springer.

 

What I find most entertaining is times when someone comes along and thinks they're going to reinvent the wheel. They think that there is some awesome new method of obtaining nearly free power just sitting waiting to be discovered still, even though ICE's have been in development and production for over 100 years now. And, best of all, they think that a "garage scientist" is in a better position to come up with these miracle power adders than the research and development teams of every major manufacturer of engines in the world, all of which are backed by tens of thousands of dollars and man-hours MONTHLY, and the best test and monitor equipment money can buy.

THAT is what I find entertaining.

Some may call it "thinking outside the box", but I'd prefer to call it "thinking outside of reality".

 

so will water injection work on cooling off the intake charge, so long as it isn't enough to choke down the engine or produce ill effects?

 

you can run timing advance with water injection on a n/a car or run lower octain gas with high compression.

I wouldn't bother except with a turbo car, just my 2 cents