[crazytrain]

Originally Posted by donmei

But, the question is: is it appropriate on a street car. For most drivers, the answer is No because engine damage can occur if you run out of water on a car tuned to take advantage of it.

Am I missing something? I don't think there are that many soccer moms debating whether or not to use water injection in their minivans and station wagons. If you are building your engine up enough to consider options like water injection, you're not driving what most people on the road would categorize as a "street car" anymore (even if you intend to drive it on the street more often than the track).

Also, forgetting to put water in a WI setup is on par with forgetting to change your oil. Yeah, it'll fry your engine, but it's because you made a stupid mistake.

[dmpi]

I can't see how WI is any better than dumping gas during high boost, which is what the STI already does.
The pumbing is already there, and it is already intergated with the MAF & ECU to meter correctly. I would also bet that evaporating gas has better cooling capacity than evaporating water.
This method has a built in fail-safe unlike WI. When you run out of gas, you run out of gas.

2nd I like to compare spraying water on the intercooler vs in the intercooler. When you spray in the intercooler, sure you may cool thing off, but you'll dilute the fuel/air charge, water vapor won't burn and you'll lose power. Also people forget that it's harder to evaporate water under 1 bar pressure.

All-in-all there is nothing wrong with the concepts of WI. The STI uses both of them, just not in the way WI was orignally designed. The way I see it, if the original WI design was so great, one of our performance auto manufacture such as Porsche, Ferrari or BMW would have picked it up.

[crashsti]

on any car that is destined to spend most of its life on the street why would you tune a car to run on the ragged edge of detonation just to gain some extra horses from water injection? i suppose if you kept a laptop in your car you could tune the combination to take advantage of water injection. run higher boost for that one street race along with water injection to get an advantage, i really don't know? in all honesty i don't think our cars have the ability to make insane power on pump gas, even with the turbo. if you want to have to big horsepower and reliability it takes a very well researched and thought out combination. perhaps WI would have a place as a finishing touch, but i would never tune a car to have to run with water injection. if the technology has come as far as some say it has then perhaps it would make a good tool on a really really hot day.

[Silverbane]

Originally Posted by dmpi

I can't see how WI is any better than dumping gas during high boost, which is what the STI already does.
The pumbing is already there, and it is already intergated with the MAF & ECU to meter correctly. I would also bet that evaporating gas has better cooling capacity than evaporating water.
This method has a built in fail-safe unlike WI. When you run out of gas, you run out of gas.

2nd I like to compare spraying water on the intercooler vs in the intercooler. When you spray in the intercooler, sure you may cool thing off, but you'll dilute the fuel/air charge, water vapor won't burn and you'll lose power. Also people forget that it's harder to evaporate water under 1 bar pressure.

All-in-all there is nothing wrong with the concepts of WI. The STI uses both of them, just not in the way WI was orignally designed. The way I see it, if the original WI design was so great, one of our performance auto manufacture such as Porsche, Ferrari or BMW would have picked it up.

LOL
I suggest wherever you got your information for how WI works that you never return to it for any technical help

A) Water has insane cooling capabilities, since its the process that converts water to steam that eliminates heat not the water itself...

B)Saab cars used WI as an OEM part before...

C)you dont spray water IN an IC, you spray it after the IC before the TB so it has time to atomize, its again the process of coverting water to steam that removes heat, not the water itself, water vapor doesnt burn, correct but it eliminates heat, you dont lose power doing this, you spray a fine MIST not gobs of water.

If your going to argue against WI, please read up on it before you knock it. I understand if your not comfortable with it but none of your points help anyone make an "informed" decision since they all are speculation.

[donmei]

Re question about just dumping fuel. Running way rich is a very effective way of cooling the combustion chamber. Remember those piston aircraft engine I mentioned. Well current turbocharged racing aircraft use 1)water/alcohol spray on the intercooler 2)water injection 3) rich of peak power mixtures.

If you want to build a quarter mile monster running rich, with enough boost is great. But if you have cats on your car, this isn't practical. Excess fuel dumped out the exhaust is burned by the cats. They will overheat and possibly melt things near them. I've see that happen. Running way rich also is not as effective as water injection. Water's specific heat (how much heat it absorbs for a given amount) Is much higher than fuel. Its funny water is so available we just assume its not optimal. Water is about the best thing you could ever use for evaporative cooling. It takes a lot of energy to change water from a liquid to a gas. Net result is cooled intake charge.

Someone mentioned that it would "cool the cylinders". You're missing the point. It doesn't cool the cylinders. You're thinking liquid. The water, by the time it reaches the cylinders is a GAS. Not a mist, or a spray, but a gas. Just like there's water in the air in the room you're in right now. You can't see it or feel it, but its there. The ability of air to carry water as a gas goes up with 1) temp 2) pressure. So the intake side of a turbocharged car is the perfect place for this to happen. Once injected, the water never leaves the gas state in your engine.

By the way, one of the byproducts of all combustion is water. So your car is making water anyway. Thats what rusts out exhaust systems. You shut the car off and some exhaust gasses are left in the pipe. The pipe cools and water condenses (gas to liquid) and rusts your exhaust from the inside out.

That said, I wouldn't put it on my car. Nothing to do with its merits. I just don't want to deal with filling it. At least not while I drove on the street.

If I could have an ecu with easily switchable settings. Stock and something else. With the something else set to take advantage of water injection, now that would be great.

Don

[donmei]

3 things I didn't think of when writing my reply.

1) Water has about twice the specific heat of gasoline, so to get equivalent cooling with fuel requires TWICE as much. So, you were talking about water displacing air reducing power. Here's my counter. Although the amount is miniscule overall, you'd need to displace 2 x as much air to get equivalent charge cooling with fuel.

2) More power at the same boost. With WI, you could lean for to peak power, as opposed to running far rich of peak in stock tune. Not a lot, but something worth considering.

3) Cylinder washing. I'm speculating here but it has been said that overly rich mixtures can result in the unburned, still liquid, fuel diluting the oil film on the cylinder wall. This makes the cylinder more prone to scuffing. Since oil is not soluble in water (even though the water is a gas at that point, but I'm playing devil's advocate) it can't wash the cylinders of their protective layer of oil.

4) Not important to some, but important to those of us who drive on the street and/or participate in endurance racing - Better fuel economy.

Hope this helps,

Don

[dmpi]

In comparing the merits of evaporating water vs. gas, Its true that water has a higher specific heat when it evaporates, but gas will evaporate at about twice as fast as water. So you can spray twice as fast to get the same results. Overall... I would consider it a push regarding which has more cooling capacity, gas or water.

Spraying water also has it problems in areas of high humidity. Such as in the SE & East Coast. Areas of high relative humidity limits the amount of water the air can hold. One thing to note is you can spray and vaporize gas long after air has reach its water saturation point.
If you in the 20% humidity of the desert SW, spraying water can be an very effective cooling method.

Overall, I don't dispute the facts that the concepts of WI are not sound. I just think that the STI already uses these concepts in a modified form, and adding WI would be more trouble than you'll gain.

[rallybred]

...on with the thread highjacking...

some excellent points, one more, water reduces the time it takes for fuel to burn - same as higher octane - in addition to it's excellent cooling properties.

[bitabur]

Originally Posted by dmpi

In comparing the merits of evaporating water vs. gas, Its true that water has a higher specific heat when it evaporates, but gas will evaporate at about twice as fast as water. So you can spray twice as fast to get the same results. Overall... I would consider it a push regarding which has more cooling capacity, gas or water.

Spraying water also has it problems in areas of high humidity. Such as in the SE & East Coast. Areas of high relative humidity limits the amount of water the air can hold. One thing to note is you can spray and vaporize gas long after air has reach its water saturation point.
If you in the 20% humidity of the desert SW, spraying water can be an very effective cooling method.

Overall, I don't dispute the facts that the concepts of WI are not sound. I just think that the STI already uses these concepts in a modified form, and adding WI would be more trouble than you'll gain.

Air at 100% humidity at even very high outdoor temps will hold much more water once it heats up inside your engine before becoming saturated. Probably to a point that the ambient humidity doesn't matter - or if it does is just the equivalent of spraying more water.

[roadrnr37]

Ok so i will try and keep this short. 1. On my boat i run water injection on a twind turbo 350 small black chevy. i run daul gale banks turbos and 20-25 lbs of boost. yes that is pounds of boost. The water injection setup that i use on that does in fact inject after the turbo and in the pressue box (differetn design than ours because it is a CARB car) There have been other models of water injectin that inject before the turbo, and it does help, however it does cool the intake charge it also beats up alittle on your turbine... so for long term apps itis not recomended.
2. Yes, using this can let you run on the ragged edge, however it also allows you to tune your engine more and also allows you to run your engine with some hotter plugs. Super cold plugs are great for raw power but suck for daily use..... One thing i think alot of people in this forum may be lacking is a "total picture attitude" if you concetrate on one and only one apsect of an engines perfromance you just defeated the purpose.
3. Now as for my home made water injection systems... i have had a few... it depends on the sistuation and what we are trying to acheive... you can really get 3 tunable results from WI system
a, power=run high boost or high timing b, gas milage using it as a "filler" in the combustion chamber c, drivability = using it to allow other parts to function properly and smoothly.

Turbo's have a been around for a long time and WI has not ever been far behind,,, don't knock it unless you really know and understand the mechanics and physics behind it. Just becaue sone web site had some figures and soem slides.....There are a lot of "young" (that is to engine perf) people that are easily swayed...if you ever question that... talk to some one who has experaince... I still ask questions ..... Because i dont know everything....

[crashsti]

roadrnr37 wrote:
Ok so i will try and keep this short. 1. On my boat i run water injection on a twind turbo 350 small black chevy. i run daul gale banks turbos and 20-25 lbs of boost. yes that is pounds of boost. The water injection setup that i use on that does in fact inject after the turbo and in the pressue box (differetn design than ours because it is a CARB car) There have been other models of water injectin that inject before the turbo, and it does help, however it does cool the intake charge it also beats up alittle on your turbine... so for long term apps itis not recomended.
2. Yes, using this can let you run on the ragged edge, however it also allows you to tune your engine more and also allows you to run your engine with some hotter plugs. Super cold plugs are great for raw power but suck for daily use..... One thing i think alot of people in this forum may be lacking is a "total picture attitude" if you concetrate on one and only one apsect of an engines perfromance you just defeated the purpose.
3. Now as for my home made water injection systems... i have had a few... it depends on the sistuation and what we are trying to acheive... you can really get 3 tunable results from WI system
a, power=run high boost or high timing b, gas milage using it as a "filler" in the combustion chamber c, drivability = using it to allow other parts to function properly and smoothly.

Turbo's have a been around for a long time and WI has not ever been far behind,,, don't knock it unless you really know and understand the mechanics and physics behind it. Just becaue sone web site had some figures and soem slides.....There are a lot of "young" (that is to engine perf) people that are easily swayed...if you ever question that... talk to some one who has experaince... I still ask questions ..... Because i dont know everything....

i think you really hit the nail on the head with you last paragraph. the original intent of this thread was to offer up some good ways to upgrade Doublej's STi. it seemed that the first idea that was brought up was water injection. i thought that it was a premature idea, although i certainly was'nt as eloquent about saying it as i should have been. when creating a total package, be it for the street, the track, or in one case the water, its all about being smart and not going overboard unless the situation calls for it. i have listened to people talk about putting 400 horsepower nitrous systems on completely stock Mustangs. i have seen people put HUGE camshafts in a car that would have more usable power from something much more conservative. people have a tendancy to want just for the sake of having something, even if it really is'nt practical. WI just did'nt seem to be a practical idea at this point.

[Carguy]

Ok guys......

1st of all... to answer the ? posted... I would go with the garrett turbo before the APS one, APS turbo's are good, but the garretts spool quicker and make the same if not better power, you need to use a oil pressure reducer to the pressure on the inlet of the turbo tho or it'll go bad in a month or 2.

11.00 in the 1/4 mile is not going to be safely achievable on a street car IMHO, you'll have to run dangerously crazy boost and or NO2 to get yoiu there. high 11's on pump gas should be ok with the supporting mods.

WATER INJECTION is worth triple the price of what the kits are going for.
Water in a fine meterd mist: cools intake charge by a ton, cleans carbon and buildup off of valves and pistons, allows you to run 4-5 psi more boost with no detonation. You have to have the setup tuned on a dyno by a pro to get it to work right, but it actually helps IMO for the long term reliability of a motor. The kits from charged perf include a indicater to let you know when the water tank is running low.

I've seen a 2.0 wrx make 40 more hp just adding WI with myt own eyes, if that doesnt sell you guys I dont know what will.

[crashsti]

I've seen a 2.0 wrx make 40 more hp just adding WI with myt own eyes, if that doesnt sell you guys I dont know what will.

this really sounds to good to be true if you ask me. the guy with the boat motor seems to have a good application for WI. a big twin turbo motor making tons of power that is constantly under load and has infinate access to water. if you think about it WI is nothing more than a band-aid fix. if you want to run ultra-high levels of boost, then do it right and use race gas. most likely you'll be doing it at the track and it'll be there. i can't get past the idea of running 5 or 6 psi more boost than the engine can safetly handle on whatever octane gas and then depend on water injection to keep everything from blowing to pieces. severe detonation does'nt take long to blow the hell out of an engine.

[bitabur]

Originally Posted by crashsti

this really sounds to good to be true if you ask me. the guy with the boat motor seems to have a good application for WI. a big twin turbo motor making tons of power that is constantly under load and has infinate access to water. if you think about it WI is nothing more than a band-aid fix. if you want to run ultra-high levels of boost, then do it right and use race gas. most likely you'll be doing it at the track and it'll be there. i can't get past the idea of running 5 or 6 psi more boost than the engine can safetly handle on whatever octane gas and then depend on water injection to keep everything from blowing to pieces. severe detonation does'nt take long to blow the hell out of an engine.

Infinite access to water? lol.... if he was running WI with the same water he was running IN, his engine wouldn't have lasted very long at all. I would even be leery about running tap water in a WI system, probably use filtered.

What you don't seem to realize is that you're depending on 100 other computerized systems to keep your car from blowing to hell also. You're never gonna get past that, WI or not. If the technology fails, you're gonna have car problems in a hurry.... this is just another kind of technology being added to the package.

It's shouldn't be that difficult to engineer in safeguards like those that are in your car already, so that if the water stops flowing the ECU stops pushing the extra boost....

[crashsti]

Infinite access to water? lol.... if he was running WI with the same water he was running IN, his engine wouldn't have lasted very long at all. I would even be leery about running tap water in a WI system, probably use filtered.

bitabur- its not as funny as it sounds. you fill your gas tank with dirty fuel all the time, you suck filthy air into your engine everyday, the only thing keeping out the dirt is filters. its not as though you run special bottled air on your engine or get special gasoline that is free of dirt and other particles. you depend on filters...so why is it so hard to believe that with a boat you could run filtered water directly from the body of water that you're boating on.