wesmi01 Posted January 18, 2003 Share Posted January 18, 2003 How much BHP do I get from water injection? Running 1.2 bar on hybrids Link to comment Share on other sites More sharing options...
Justin Posted January 18, 2003 Share Posted January 18, 2003 You don't get any I think mate. It is just a safety device to cool your turbos and stop em exploding at higher boost. Worth avin though for the money. Cheers Just Link to comment Share on other sites More sharing options...
wesmi01 Posted January 18, 2003 Author Share Posted January 18, 2003 Um well I thought the idea was to cool the air such as the IC does!! The colder the air the denser it becomes, thus more air in the engine equals more bhp!!!! But you may be right sir?!?!?!? Link to comment Share on other sites More sharing options...
Alex Posted January 18, 2003 Share Posted January 18, 2003 It's back up to the IC, that's all. Link to comment Share on other sites More sharing options...
wesmi01 Posted January 18, 2003 Author Share Posted January 18, 2003 But does a IC not give more BHP? Link to comment Share on other sites More sharing options...
THOR Racing Posted January 18, 2003 Share Posted January 18, 2003 The IC and Water Injection, H20i as I like to call it both have the affect of cooling the compressed air charge down. This in itself does not give you more power. After all it hasn't increased the pressure of the air has it? BUT! What it does do is indirectly give you the ability to obtain more power. Fuel is obviously mixed with air to create an explosive mixture but some of the fuel is ONLY being used to cool the air charge down (as a heat sink). So the car's running so rich to compensate for the rises in charge air temps. What a better IC and H20i gives you is lowered charge air temps thus you don't need that extra fuel anymore for cooling instead you can use it for buring to create more energy. Of course to use that extra fuel you'd need to increase boost a little to get more air to mix with it and that in itself increases the charge air temps as the turbos compress more and more air into the same space the little molecules smash together even more and create even higher temps. This is where the turbos then start to become inefficient, creating too much heat without a parallel increase in density (pressure of the air charge) The name of the game is to increase the turbo boost pressure a little so that the turbos are on the nee point of inefficiency and then add a bigger IC or H20i to compensate for the increased charge temps. It's all a bit of a game, a game of routlette at that. So you could increase the boost a lot more and still be O.K. BUT..... this is where H20i falls down. It's only as good as the pump. If the pump fails... you fail to cool the charge temps down.... the combustion temps rise and..... you get knocking which is pretty bad (often terminal) for the engine. So it's fine while its working but we like to say.... DON'T RELY ON IT! A bigger IC on the other hand is a mechanical block which you'd find pretty hard to fail and thus is a safer bet. Having said all that I use my H20i as a safety backup in the summer during spirited driving, to give me that extra protection from knock. Regards Pete ps. I may not be 100% on everything..... Link to comment Share on other sites More sharing options...
Guest Ash Posted January 18, 2003 Share Posted January 18, 2003 You don't get any increase as a result of water injection as water doesn't burn. In other words, water does not add to the combustion process and it's the process of combustion that drives your engine. Nope, it doesn't cool the air just as the IC does. The IC does not inject any of the outside air but merely provides a "heat exchange". Injecting water molecules merely dilutes your incoming air/fuel charge by the requisite degree of water molecules you choose to inject. Kennel Link to comment Share on other sites More sharing options...
Mark D Posted January 19, 2003 Share Posted January 19, 2003 TRL Performance wrote Fuel is obviously mixed with air to create an explosive mixture but some of the fuel is ONLY being used to cool the air charge down (as a heat sink). So the car's running so rich to compensate for the rises in charge air temps. What a better IC and H20i gives you is lowered charge air temps thus you don't need that extra fuel anymore for cooling instead you can use it for buring to create more energy. End quote Am I right in thinking then that a better cooling system such as a more efficient IC could improve your mpg if you could adjust the amount of fuel delivered. If the air is cooler and you get 'more bang for your buck' we should save all that fuel that was being used as a heat sink. Is this why some people have an afc? Am I right guys or did I not understand what he meant? Will I be the first to own a 50mpg (urban) supra or will I have to wait until I convert it to a diesel engine? Link to comment Share on other sites More sharing options...
THOR Racing Posted January 19, 2003 Share Posted January 19, 2003 Nope, it doesn't cool the air just as the IC does. Umm....I believe I said "both have the affect of cooling the compressed air charge down." I didn't say they used the same method. IC cools the charge down by removing heat through conduction and convection. Adding or removing nothing, apart from a drop in pressure of the charge (gas laws etc) H2Oi replaces (or adds to) the air and fuel molecules. I think diluting is a confusing term. The air to fuel ratio is the same, all you've done is add another chemical into the combustion process. One that is in fact a by product of combustion anyway. It's not used in any way during combustion (except if you have added an alcohol screen wash or something, which in inself is a fuel type) Now a certain percentage of the water will absorb heat from the surrounding air molecules. (This heat would have normally been absorbed by the fuel alone). Thus this means you have an overall cooler charge. I don't know the exact physical or chemical reactions but I can see that the air and fuel molecules are now cluttered with water molecules and that this must have an adverse effect on combustion somehow. But I suspect that the overall gain due to lower charge temps (through the water absorbing the heat) means the combustion process is in the end more efficient. Am I right in thinking then that a better cooling system such as a more efficient IC could improve your mpg if you could adjust the amount of fuel delivered. MPG is generally based on cruising at a fixed speed etc. This means the engine is not under that much load and uses the closed loop response for fueling. i.e. it senses the O2 sensor and adjust fuel accordingly. The moment you hit the throttle hard it switches from closed to open loop control and the fueling is dependant on the boost pressure. You do use simple fuel controllers like the AFC in this situation but all they do is modify the boost pressure signal fooling the ECU into adjusting fueling. You do sometimes reduce fuel when it's too rich at lower RPM ranges, this sometimes gives you a better response but as to how much fuel you're going to save. I'd forget it. You go from a steady 7->10% injector duty cycle when crusing at 80mph say to >80% at WOT (sometimes pretty much 100% on a modded car). So the amount you're going to save in the 80% bracket would have to be very large to make any impact at all on the MPG figure. As most of the time you'd be hardly using the injectors. And for those that say "but I'm never crusing, I'm always racing", you're not bothered about MPG anyway! Is this why some people have an afc? No. Not normally. Normally (most useful) the AFC is used with larger injectors to lean off the fuel (as the injectors are larger, you have to lean off the low to mid range to compensate back to the original injector size). But some people use the AFC to give a richer or leaner mid-range response, this can improve a dead spot somtimes. Not sure the improvement is worth it, if you want every last ounce out of the engine then probably yes. This type of controller cannot give you more fuel though at wide open throttle. 100% is 100% no matter how much the AFC increases the signal by. Regards Pete Link to comment Share on other sites More sharing options...
Guest Ash Posted January 19, 2003 Share Posted January 19, 2003 I think diluting is a confusing term. The air to fuel ratio is the same, all you've done is add another chemical into the combustion process. Yes, the air/fuel ratio remains the same and I apologise for any confusion. What I meant was: dilution in the sense of the overall combined fuel/air charge pertaining to each cylinder fill. The key aspect to hold in mind is the flow characteristics remain the same. So, add another chemical into the intake and the original chemical-mix flowing through that intake and entering the cylinder will be reduced by the same percentage addition of whatever that "additional chemical" happens to be. In this case it is water. It's all very well presenting the fact that the latent heat of evaporation of water is much greater than that of petrol, etc. Such talk makes great headlines and gets people buying water injection systems. However, the big downer with water is it does not burn. Inject water at 3% (say) as a volume of the original cylinder fill and you'll end up with a cylinder with only 97% of the fuel-air mixture it had before. The rest being made up with the injected water. Again, as water does not burn, and as you now have 3% less fuel/air mixture entering the cylinder, the amount of power generated will be reduced by the same amount. The IC and Water Injection, H20i as I like to call it both have the affect of cooling the compressed air charge down. This in itself does not give you more power. After all it hasn't increased the pressure of the air has it? Cooling the intake air will most certainly increase engine power. Provided, of course, the requisite amount of additional fuel is injected and a "free" way of cooling the compressed air is available: as the cooler the air the greater the density. Now a certain percentage of the water will absorb heat from the surrounding air molecules. (This heat would have normally been absorbed by the fuel alone). Thus this means you have an overall cooler charge. Yes, but you now have the problem of having added water to that same charge. But I suspect that the overall gain due to lower charge temps (through the water absorbing the heat) means the combustion process is in the end more efficient. Again, you are failing to consider that the water enters the cylinder. If the injected water evaporated in the intake, cooled the compressed air, and then just buggered-off somehow that would be great. But it enters the cylinder... and that's where the water-injection theory falls down. As for combustion efficiency: the only way you can make the combustion process "more efficient" is by speeding it up, not slowing it down. Kennel Link to comment Share on other sites More sharing options...
Thorin Posted January 20, 2003 Share Posted January 20, 2003 I should imagine that if using Water injection on a summers day there would be no more water in the intake than without WI on a wet day. Link to comment Share on other sites More sharing options...
THOR Racing Posted January 20, 2003 Share Posted January 20, 2003 Inject water at 3% (say) as a volume of the original cylinder fill and you'll end up with a cylinder with only 97% of the fuel-air mixture it had before Yes I agree. But wasn't the 3% of fuel that's just been shoved out of the way and replaced with water being used as a heat soak anyway. It doesn't combust fully and leaves the exhaust. Hence you get rich O2 sensor readings, meaning unburnt fuel. the latent heat of evaporation of water is much greater than that of petrol So doesn't this mean the fuel that was just going to be thrown away anyway is being replaced with water which can absorb more heat, and it too gets thrown away in the end. Neither contribute to the combustion? (skating on thinner ice here!) . If the injected water evaporated in the intake, cooled the compressed air, and then just buggered-off somehow that would be great. But it enters the cylinder... and that's where the water-injection theory falls down. Yes I understand your point and agree this is the sticky point and tried to explain some reasoning above. But I thought you got reduced EGT which suggests that the water mix is doing something so it may not be perfect (not as good as a larger IC I agree) but it's doing some good. I guess you will not agree on that which is fine and I cannot convince myself 100% either. I think it has some good points and probably just as many bad points but not enough to say water injection is rubbish. Can't say as I know of anyone who has taken a full range of temps (Intercooler inlet, outlet and EGT) and placed on a dyno and run it and compared the end result. You are right and it could be a big con but I'd like to see some evidence first before I dismiss it altogether. Equally you'd like to see it prove your point which I can understand Interesting conversation though Got me thinking..... Regards Pete Link to comment Share on other sites More sharing options...
paulrenn Posted January 20, 2003 Share Posted January 20, 2003 The benefit of WI is that you can run more advanced ignition and higher boost due to the cooling effects. For some great techical info on the ERL WI system, and Toyota tuning stuff in general, visit my friend's website: here Link to comment Share on other sites More sharing options...
wesmi01 Posted January 20, 2003 Author Share Posted January 20, 2003 Cheers for the info guys!!! Link to comment Share on other sites More sharing options...
Guest Terry S Posted January 20, 2003 Share Posted January 20, 2003 Paul, Dennis is a legend! He is currently helping me out with something on the Autronic. Good friend to have! Link to comment Share on other sites More sharing options...
paulrenn Posted January 20, 2003 Share Posted January 20, 2003 Wow Terry, small world eh! I've known Dennis around 6 years. He really does know what he's talking about when it comes to tuning Link to comment Share on other sites More sharing options...
Guest Ash Posted January 20, 2003 Share Posted January 20, 2003 Pete, please don't get me wrong. I'm not trying to say that the idea of water injection is a big con. It's just that I do very much enjoy a lively technical debate. It gets us all thinking which can only be a good thing. There is nothing like being able to exploit a niche market. By definition, your customer-base is limited but, if you can compensate by selling the product at 500% markup, say, as opposed to the typical mainstream markup of 100% then it's still a big profit earner. The original question posed by the thread was how much power can water injection provide? Problem is, power and water tend not to mix. Take water to a flame and goodbye flame. As an internal combustion engine generates power proportionate to the heat of combustion I'm fascinated how, by adding a component that quenches combustion, such can possibly make more overall power. I can only assume that the water is compensating for an important and overlooked factor; to the extent where, if that factor were no-longer overlooked, the paltry (so called) gains provided by water injection would pale into insignificance. To me, it's a bit like a person with a dodgy ticker having a Pacemaker fitted. Keeps it beating and all seems well. But that 400m sprint is still just as out of reach as ever. Kennel Link to comment Share on other sites More sharing options...
Terminator Posted January 21, 2003 Share Posted January 21, 2003 James, I understand the arguments water and flame don’t mix. but in injection we are talking about mist of water not a bucket full. Water is H2O, H is flammable and O supports combustion. In the extreme environment of the cylinder, perhaps there is no negative impact as the water is broken down into these two gasses. The positive effect is the cooling of the charge. Link to comment Share on other sites More sharing options...
Guest Ash Posted January 21, 2003 Share Posted January 21, 2003 Phil, it's getting late and it's nice to talk with you again. I'll come back to the thread tomorrow and we'll discuss the issue further. After all, I've been so wrapped up in my business problems the past year or so, it's nice now to come back and have a darned good tech dicussion with some old friends. I've missed that. Yours, James Link to comment Share on other sites More sharing options...
Keith C Posted January 21, 2003 Share Posted January 21, 2003 Bunch of posts deleted to return to what was a reasonable discussion. Apologies to all affected. Link to comment Share on other sites More sharing options...
Syed Shah Posted January 21, 2003 Share Posted January 21, 2003 Interesting debate. James, have you looked into Methanol injection, a guy in the states is using on his Supra to great sucess. Check it out on the AEM forums, his screenname is BLKMGK. Link to comment Share on other sites More sharing options...
Terminator Posted January 21, 2003 Share Posted January 21, 2003 Originally posted by Syed Shah Interesting debate. James, have you looked into Methanol injection, a guy in the states is using on his Supra to great sucess. Check it out on the AEM forums, his screenname is BLKMGK. Any chance of a link Syed, this sounds interesting. Link to comment Share on other sites More sharing options...
Adam W Posted January 21, 2003 Share Posted January 21, 2003 I saw a 3000GTO with propane injection last week, the owner reckoned it was like a nitrous hit when it came in . . . BTW, we're having to pay strong money to dispose of about 50 gallons of methanol a week at work, if it wasn't contaminated with experimental drugs I'm sure us lot could dispose of it much cheaper...unless we just get Justin to drink it? Link to comment Share on other sites More sharing options...
Terminator Posted January 21, 2003 Share Posted January 21, 2003 I am sure we could burn them off. Link to comment Share on other sites More sharing options...
Keith C Posted January 21, 2003 Share Posted January 21, 2003 Originally posted by Adam Wootten I saw a 3000GTO with propane injection last week, the owner reckoned it was like a nitrous hit when it came in . . . BTW, we're having to pay strong money to dispose of about 50 gallons of methanol a week at work, if it wasn't contaminated with experimental drugs I'm sure us lot could dispose of it much cheaper...unless we just get Justin to drink it? Bring it to Billing... Link to comment Share on other sites More sharing options...
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