chinoy

Ok a bit frustrated just spend 2 hours reading 10 pages about water injection and aquamist but didnt get info looking for.

Some simple questions if they could be answered with simple one liners.

1. Watter before the impler misted or not. WIll it eat the compresor wheels has anybody actually tried it or we just guesing it will.

2. Our goal is droping charge temp and detering deto. Right.
SO all those guys puting in aquamist I dont see a single post with figures. Could somebody please throw up some numbers.

a. Is there a temp beyond which we dont see gains. Somebody said 40c. Im allready seeing 40c without aquamist. Can people throw up real numbers like this.
Before puting in the intercooler charge temp 99c
After puting in intercooler charge temp 45c
After puting in air scoop over intercooler charge Temo 38c
Throwing dry ice on intercooler charge temp 10c
After Aquamist temp ??
Is there a limit beyond which gains are a waste of time. Or not worth the effort.

Droping charge temp just so that you can run more timing isnt going to give you any power gains. There is an optimum timing for every engine and if your there without aquamist Is it worth chasing an aqua mist system. On our car this is arround 24 deg. Starts at 2 deg. By 2000 RPM its 28 Deg. Then boost starts to push the vacum advance arm back and it move back to 20 deg at full boost. Which is 10 psi most days. Tip of plug electrode shows a tinny narrow band indicating timing is spot on.
So why am I still thinking aquamist. Cause want to head out from 10 psi towards 20 psi. But couldnt find any real facts or numbers to guide ?

3. We have seen the effect of deto on a piston. What is the effect of watter on the piston. Somebody told me. It could loosen huge chunks of carbon that could eat your valves true / false. It could crack your piston. True / False.

Koby

Yes it will damage your impeller wheel. 150,000 RPM making contact with a solid like water is not good news. The density of the air with water in it would bring the compressor to a hault and likely shatter/bend fins.

In the DSM world with water/alc people generally go from boost levels of 14-15psi up to 18-20 with ZERO knock. It is like running race gas everyday. Lucas English (www.englishracing.net) has managed to pull off 12.3x passes in his full weight talon on the stock injectors, clutch, turbo, intercooler, and pump gas. All because of water/alc injection.

You will always see gains with colder tempatures, the denser the air the more you can stuff in each cly and burn. more air is more power.

Timing is a tricky science. Lots of guys juggling timing/boost find that you can run faster times with less boost and more timing. Usually more boost will get you a higher MPH but you'll have slower ET's


No. Very doubtful. But obviously if you're worried about having enough carbon built up on your pistons you better go pick up some combustion chamber cleaner and run a bottle through the engine, and let another one soak on the pistons overnight.

Tom-Guy

Dropping charge temp? Not particularly. What is commonly experienced is "wet thermometer styndrome" where the water injected puddles on the IAT and sucks up the heat out of it and out of the intake manifold - before drawing that heat into your engine.

Deterring detonation? Right on!

The thing that a rich AFR mixture does is leave unburnt hydrocarbons in the combustion chamber that latch onto the heat in the chamber and carry it out of the engine. So that the engine doesn't melt down. Water has a "high heat of evaporation" which means it can latch onto and suck out of the combustion chamber a LOT more heat than normal gasoline.

The point at which your fuel of choice can no longer do this is called knock limit. When most people - or who cares about them - when I say knock limit I mean "knock limit for pump gas" which is 92-93 RM/2 octane. Richer men than I purchase racegas and suchlike.

Up until you reach knock limit, there is little point in water or water/diluent injection. Diluent means something you can dilute/disolve, like acetone or "cetane improver" or methanol or methylamine (heh). The point of water injection is to make more power than is otherwise possible with your fuel of choice - most naturally aspirated engines need not apply. For a boosted setup, it is IDEAL.

Charge temps? No, you always see gains off of lowered charge temps. As low as you can get your charge temps, the better. While the drop in temps you see from water injection are semi-false, keep in mind that the drop in charge temp as a boosted engine's charge speeds approach mach .4 or so is significant, and a good thing. But don't confuse high charge temps as being bad, depending on your setup. Pfft. I should be ending up with the second electronic water injection prototype controller board from www.myo-p.com, since Dan Nicoson is my goddamn homey. I plan to use it to hit 300 whp off a D16 with no intercooler - tap water is cheaper than an IC, you know. Regardless of charge temps, water injected into the combustion process latches onto and removes heat from the engine.

Nope. Retuning your ignition, with water injection, is mandatory AND will result in slightly less power WOT at the same boost level (part throttle power, mpg, and bsfc figures with water injection are always improved).

This is irrelevant.

Pay it no attention. What is important is you can now run more boost than ever before, and make more power than you could otherwise. You will, of course, have to tune your ignition to suit the water injection.



If you have huge chunks of carbon on your pistons, your engine won't last long anyway.

Water injection will not effect the longevity of your engine. Refer to pre-war (as in pre World War ONE) tests that proved this conclusively.

Tips:

- Gains in power and knock limit are to be had until you are injecting 50% as much water as fuel, by volume.

- You get 2.5 times more knock limit injecting 50% as much water as fuel, by volume, as you do injecting 25% as much water as fuel, by volume.

- You inject enough water, and the engine's cooling jacket stops being used - you don't even need coolant in the engine anymore. Given your air cooled engines, you may want to go with a hotter plug in such a situation. :P

- Atomization is a problem with straight water - although nothing cools as well as straight water. Acetone does wonders for reducing surface tension so that water atomizes through a fuel injector. What the aquamist nozzles do is a brute force thing - which isn't bad - just keep in mind it's not finesse. Dunno what you have in India, but we have $0.99/gallon methanol/water windshield washer fluid that is a very popular thing to run.

How good is your english? I have some engineering level papers I'd like to link to you.

Koby

Methanol injector is far better than water BTW.

Water actually does about 4x more cooling that alky. Water takes about 23,000 J/gram to vaporize while alky takes 8,000 J/gram, think about how easy alcohol evaporates when exposed to air and how much longer water takes. Water accually slows down the combustion process while meth helps control and add's to it.

Tom-Guy

Slows down the combustion process *proportional* to the amount injected, sure - so what's the problem? Inject less, moot point.

Problem is water's surface tension/unwillingness to atomize. See my post above.

BTW, GVR-4 #366/2000 runs 7.62@92 mph in the 1/8th on C10 off we don't know how much boost - there's a peg on the boost gauge that keeps the needle from going much past 30 psi. Amusing thing to watch, I must remember to get video. It's kind of sad, we were running 7.8x@90 off of 24 psi, but having zero traction in 1st gear and spinning a bit through 2nd sucks like that. Not bad for a stock 160K mile bottom end, eh?

chinoy

Well thanks for the great info.
Latest development disconected waste gate. Couldnt see focus on boost gauge after it pased 16 PSI but still no knock.
I know I have to go watter injection if only to control temps.

Me English not bad. And reading SAE pappers from morning to night is what I do anyway.

Chk out this on if you can. Even got pics of droplet shapes and sizes and math models to calcuate pretty much anything.

Carburetor Modeling - A literature review of previous wor on air and fuel flow inside the carburator passages. Diego A. Arias University of Wiscosin Mechanical Eng. Dept 2003

You can mail me any pappers you have relating to this and Ignitions to rdchinoy@gmail.com in particular info on modeling the Ignition process. Some of the best work in the feild seems to be hapening in Isriel via NASA funding.