Anybody use water injection?
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For those who think Water Injection does not belong to the proper tuning world, think again... 
Putting aside the problem of running out of water for the time being, someone has managed to 'GAIN' power instead of what Shiv said on his last post -
quote:
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Originally posted by Shiv of Vishnu
"immediately resulted in a massive across-the-board torque loss"
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Despite strong resistance from the tuner, NavyBlue has managed to persuade his tuner to tune with water injection with a proper air/fuel (approaching) and has yield excellent power gains, some 40-80 bhp and 40-50 ft-lb increase! at no- time has experienced any knock !!! :banana: :banana: :banana:
I thought you might be interested in reading this web page:
http://forums.nasioc.com/forums/show...ferrerid=33979
Just my 2c
Peter Head - Observer
Putting aside the problem of running out of water for the time being, someone has managed to 'GAIN' power instead of what Shiv said on his last post -
quote:
--------------------------------------------------------------------------------
Originally posted by Shiv of Vishnu
"immediately resulted in a massive across-the-board torque loss"
--------------------------------------------------------------------------------
Despite strong resistance from the tuner, NavyBlue has managed to persuade his tuner to tune with water injection with a proper air/fuel (approaching) and has yield excellent power gains, some 40-80 bhp and 40-50 ft-lb increase! at no- time has experienced any knock !!! :banana: :banana: :banana:
I thought you might be interested in reading this web page:
http://forums.nasioc.com/forums/show...ferrerid=33979
Just my 2c
Peter Head - Observer
Last edited by peter head; Dec 22, 2003 at 06:48 AM.
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From: Flying on the H1 w/ 75 psi of compression on all 4 cyl
Car Info: PnP VF30 w/ STi injectors Perrin intake walbro fuel pump w/ a TXS TBE
That was a very interesting read. Especially were they get into pushing the stock turbo to 20 psi
. 300 buck for WI ??? cash for a good tune. Man thats a new bang for the buck mod. :banana:
. 300 buck for WI ??? cash for a good tune. Man thats a new bang for the buck mod. :banana:
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From: Reno, NV
Car Info: 1993/2000/2001 GF4 mostly red
My apologies to the board for not responding to this thread again in September when it was posted, an oversight on my part. I have read the responses to this thread, as well as Ed's paper, and I would modify my initial statement to say that WI is a $300 band-aid to a lack of fuel management. However, I know that this response is not sufficient for those of you with more knowledge of tuning than faith in salty internet nerds like myself, so I am going to spend the time to properly research this issue and form a well-supported, well-structured response. I reserve the right to alter my original postion, but I do not expect to do so significantly.
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Search through and read Turboice's 'water injection paper' I have come to the conclusion that Shiv's experience of " tuning three WRXs and concluded that Water injection is useless" was not Gospel. 
There is also a thread on the following forum where there is a visual proof (power plot) of a newly water injected WRX suffered a 40+whp loss due to water injection under Vishnu's stage2+ MAP.
http://www.clubwrx.net/forums/showth...657#post334657
I would like someone to tell me exactly what is going on between the two conflicting results. Please try to be specifiy regarding the implimentation of water injection usage, not about the long term feasibility study and reliability issues.
Can someone challenge Shiv's ability to tune with water injection?
Peter Head - observer
There is also a thread on the following forum where there is a visual proof (power plot) of a newly water injected WRX suffered a 40+whp loss due to water injection under Vishnu's stage2+ MAP.
http://www.clubwrx.net/forums/showth...657#post334657
I would like someone to tell me exactly what is going on between the two conflicting results. Please try to be specifiy regarding the implimentation of water injection usage, not about the long term feasibility study and reliability issues.
Can someone challenge Shiv's ability to tune with water injection?
Peter Head - observer
Last edited by peter head; Dec 22, 2003 at 07:13 AM.
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It is good to see some healthy skepticism on internet boards and even better when claims or information are backed up with support.
In short:
Once you hit 12.0:1 AFR with gasoline - no engine is so inefficient that there is still any oxygen left to combust any additional gasoline - it just aint going to happen. With more efficient engines like most forced induction engines on the road today this occurs at 12.5:1 AFR. On really efficicent engines this occurs at 13.0:1 AFR. The point where you have just used all the oxygen in the induction charge is the point where you will utilize the most energy from combustion. There are many reasons for this due to the checmical and thermodynamics of combustion and the design of the internal combustion engine.
The reason for additional gasoline injection beyond these levels has nothing to do with power creation. It has everything to do with knock suppression through charge and cylinder cooling. The boost being run increases the power - the extra gasoline stops knock. There are two problems with this - first gasoline is a lousy coolant it has a very low specific and latent heat it takes a lot of it to absorb heat and suppress knock (this is why the factory runs 10.0:1 in case someone decides to try 89 octane). The second issue is a well established chemical fact that excess hydrocarbons that are present during combustion interfer with the CO => CO2 oxidation process. This is the process where a majority of the energy realeased from hydrocarbon combustion comes from. By eliminating the excess hydrocarbons (lean fueling) and you get more power. What every tuner is saying is if you use so and so octane I will pull this much of the fuel and you will get more power - yes they will all use different methods of boost and timing around this idea to "differentiate" themselves - but unless they are increasing boost a LOT they are pulling fuel from the OEM settings. And if they aren't pulling fuel it is because they are pushing a lot more air in and telling the ECU they aren't - still the result is a leaner fuel mixture.
Water has six times the heat absorbtion of gasoline, methanol has a multiple of the heat absorbtion as well. This means that for each unit of gasoline that you pull from the induction mixture with only one-sixth as much water you will get the same heat management and knock suppression as the gasoline that not only wasn't burning in the cylinder (most is burning in the cat if you have one) but was actually inhibiting combustion in the cylinder. Net you actually inject less liquid in the cylinder which allows more room for your guessed it - air and hence oxygen. Add to that the intercooling properties of water injection and other roles it plays and you have a higher VE in terms of gases through the strokes.
This was the simple explanation.
The paper goes into it a bit more and also has references to books and engineering papers that are well established and peer reviewed. As with all things be skeptical and seek out the back up and underlying support for claims. Other than experience and reputation of those who have made claims against water injection whether directly in a post or in a couple paragraphs in a pop automotive book, I have not been able to find any objective support for the claims against it - they are always subjective.
This does not mean water injection is for anyone or everyone. The real reasons for not using water injection include things like - not being permitted by a sanctioning body, the setup and fuel being used can be tuned without knock at power optimizing or economy optimizing fuel levels, or the user simply does not want the additional complexity in maintenance and monitoring an additional system on their vehicle. The last one is paramount since using water injection involves participation in maintenance and monitoring on the part of the user and is not a set or forget situation as with traditional fuel dumping. If there is a WI system failure and there is no automated response to such a failure it is highly likely that the tune of the vehicle will destroy their engine.
Ed.
In short:
Once you hit 12.0:1 AFR with gasoline - no engine is so inefficient that there is still any oxygen left to combust any additional gasoline - it just aint going to happen. With more efficient engines like most forced induction engines on the road today this occurs at 12.5:1 AFR. On really efficicent engines this occurs at 13.0:1 AFR. The point where you have just used all the oxygen in the induction charge is the point where you will utilize the most energy from combustion. There are many reasons for this due to the checmical and thermodynamics of combustion and the design of the internal combustion engine.
The reason for additional gasoline injection beyond these levels has nothing to do with power creation. It has everything to do with knock suppression through charge and cylinder cooling. The boost being run increases the power - the extra gasoline stops knock. There are two problems with this - first gasoline is a lousy coolant it has a very low specific and latent heat it takes a lot of it to absorb heat and suppress knock (this is why the factory runs 10.0:1 in case someone decides to try 89 octane). The second issue is a well established chemical fact that excess hydrocarbons that are present during combustion interfer with the CO => CO2 oxidation process. This is the process where a majority of the energy realeased from hydrocarbon combustion comes from. By eliminating the excess hydrocarbons (lean fueling) and you get more power. What every tuner is saying is if you use so and so octane I will pull this much of the fuel and you will get more power - yes they will all use different methods of boost and timing around this idea to "differentiate" themselves - but unless they are increasing boost a LOT they are pulling fuel from the OEM settings. And if they aren't pulling fuel it is because they are pushing a lot more air in and telling the ECU they aren't - still the result is a leaner fuel mixture.
Water has six times the heat absorbtion of gasoline, methanol has a multiple of the heat absorbtion as well. This means that for each unit of gasoline that you pull from the induction mixture with only one-sixth as much water you will get the same heat management and knock suppression as the gasoline that not only wasn't burning in the cylinder (most is burning in the cat if you have one) but was actually inhibiting combustion in the cylinder. Net you actually inject less liquid in the cylinder which allows more room for your guessed it - air and hence oxygen. Add to that the intercooling properties of water injection and other roles it plays and you have a higher VE in terms of gases through the strokes.
This was the simple explanation.
The paper goes into it a bit more and also has references to books and engineering papers that are well established and peer reviewed. As with all things be skeptical and seek out the back up and underlying support for claims. Other than experience and reputation of those who have made claims against water injection whether directly in a post or in a couple paragraphs in a pop automotive book, I have not been able to find any objective support for the claims against it - they are always subjective.
This does not mean water injection is for anyone or everyone. The real reasons for not using water injection include things like - not being permitted by a sanctioning body, the setup and fuel being used can be tuned without knock at power optimizing or economy optimizing fuel levels, or the user simply does not want the additional complexity in maintenance and monitoring an additional system on their vehicle. The last one is paramount since using water injection involves participation in maintenance and monitoring on the part of the user and is not a set or forget situation as with traditional fuel dumping. If there is a WI system failure and there is no automated response to such a failure it is highly likely that the tune of the vehicle will destroy their engine.
Ed.
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Originally posted by peter head
I would like someone to tell me exactly what is going on between the two conflicting results. Please try to be specifiy regarding the implimentation of water injection usage, not about the long term feasibility study and reliability issues.
Can someone challenge Shiv's ability to tune with water injection?
Peter Head - observer
I would like someone to tell me exactly what is going on between the two conflicting results. Please try to be specifiy regarding the implimentation of water injection usage, not about the long term feasibility study and reliability issues.
Can someone challenge Shiv's ability to tune with water injection?
Peter Head - observer
Keep in mind that during that tune the initial loss was only when water was engaged and on the original tune. Shiv did tune back to the original power levels - but I believe either the water injection system had not been implemented to flow sufficient water or that he left something on the table.
Shiv is extremely talented and experienced. I personally wouldn't challenge his ability to tune with water injection, I am very confident that he is able to. I believe he has a good grasp of the technology and what it is and isn't. I also believe that he is very conscientious and concerned for a customers vehicle - he may well be being conservative understanding the dangers to the engine if the water injection failed. While I have circuits that can be used with the stock ECU to respond to a failure on that implementation there is no response for it. Shiv may have left the final tune in such a condition that if water injection failed that the timing response to knock would be sufficient to keep the engine in a safe condition.
If you use water injection to its full extent the Subaru ECU timing adjustment for knock would not be sufficient to save the engine - it would require a cut in boost and an increase in fueling along with the timing adjustment. I can cut the boost on a failure but have not come up with a clear cut way to increase fueling using for instance the DD fuel adjustment. One possible way would be to tell the ECU the coolant is cold and it goes to start-up fueling but I would prefer a clearer adsjutment to fueling. XEDE and UTEC both have the ability to switch to a richer fuel setting by map switching.
Ed.
Last edited by jehcpa; Dec 22, 2003 at 07:36 AM.
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Ed,
I have been thinking about this functionality using the UTEC. It might be possible to do something with the remote switch. You could build some circuitry that would allow for the normal switch selection to pass through, but in the case of a H2O failure you could force the selection of a specific map (let's say map 5 for example). Of course that map would have to have a "safe" map in it. I can't imagine the circuitry for this being too difficult to build. Something similar should also be possible for the XEDE.
I have been thinking about this functionality using the UTEC. It might be possible to do something with the remote switch. You could build some circuitry that would allow for the normal switch selection to pass through, but in the case of a H2O failure you could force the selection of a specific map (let's say map 5 for example). Of course that map would have to have a "safe" map in it. I can't imagine the circuitry for this being too difficult to build. Something similar should also be possible for the XEDE.
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Yes you are correct on both counts. A transistor circuit should be sufficient for both units to switch maps. Of course with UTEC you have to be below a certain rpm I believe and with the XEDE you could do it on the fly theorectically - but I have no idea what would happen in the second that it takes to switch maps.
Thus far other than my own testing circuits I have installed a circuit to cut boost to the wastegate max by basically using a circuit to break the boost solenoid circuit on several cars.
At a minimum this needs to be done for a low water situation. While I think the fia2's fault system is pretty good I have found it touchy at times. It has never failed to indicate a fault when I created one - the problem is that sometimes it indicates a fault when there isn't one. The DDS2 is a much better way to monitor for faults - a low flow indicates a block and a high flow indicates a post pump leak. The DDS2 can be integrated to cut boost or switch maps.
The boost cut needs to be instantaneous since switching maps on the fly could be pretty severe. If a fault occurs the boost is cut and then the driver stops the car and switches maps to a safe nonWI one.
Thus far other than my own testing circuits I have installed a circuit to cut boost to the wastegate max by basically using a circuit to break the boost solenoid circuit on several cars.
At a minimum this needs to be done for a low water situation. While I think the fia2's fault system is pretty good I have found it touchy at times. It has never failed to indicate a fault when I created one - the problem is that sometimes it indicates a fault when there isn't one. The DDS2 is a much better way to monitor for faults - a low flow indicates a block and a high flow indicates a post pump leak. The DDS2 can be integrated to cut boost or switch maps.
The boost cut needs to be instantaneous since switching maps on the fly could be pretty severe. If a fault occurs the boost is cut and then the driver stops the car and switches maps to a safe nonWI one.
Last edited by jehcpa; Dec 22, 2003 at 08:23 AM.
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Yeah, it's 1600 RPMs - guess that doesn't help on a WOT run. Have you tried talking to TXS? There is still a unused pin on the accessory plug, in theory it could be used to trigger some fuel/boost/timing changes like they do with temperature correction.
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I use Xede and do not have a UTEC unit. I have worked with both ChipTorque and EcuTek on integration of these systems. I have not as yet been in contact with TXS as I do not have their unit. I need to take the time to contact them, but have not gotten around to it yet. I also am not sure of their interest level but would be interested in engaging them in a conversation.
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There seems to be a larger number of UTEC owners than XEDE owners (not to say one is better than the other). I know that many are using WI with UTECs and would be interested in this kind of functionality.
Oh yeah - Thanks for taking the time to R&D safety systems like this.
Oh yeah - Thanks for taking the time to R&D safety systems like this.
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The units I have tested and worked with so far have been more a matter of contacts already made than any decision on the product. UTEC is very powerful as a tool and has the marketplace. I just need to make the contact and see if there is anyway that I can add value there - it is a very informed market on the UTEC side and very capable users. I have provided advice to people on the broad tuning technique and fault response and they have always been able to achieve their goals with their UTECs because of the broad knowledge base available.
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Nathan, Phil, and Pete at TurboXS are great to work with. They are very open to suggestions for product improvement and have in the past implemented many user requested features. Also, another board to hit a large number of UTEC users is www.wrxhackers.com.
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jehcpa and cobraKLR, thank you both for your responses.
You have both surged ahead on my original question, rather spending a bit more time on the reason why Shiv couldn't make water injection work on his tune - you were providing solutions for what to do during or after water injection fails.
I would like to comment on your earlier reply on accepting Shiv is a good and talented tuner, but he prefers to leaving something on the plate and at the same time leaving his customer to pay the excess fuel bill for the years to come.
My immediate reaction would be Shiv maust have a very large plate. After seeing a gain of some 50-80 whp gain on 260whp from base line on [annointed's] tune against Shiv's 8whp loss tune on WRX-hellfire's 250whp baseline with water injection, he has left nearly 85-115 whp on his plate - extracted from the power chart on the other site.
http://www.clubwrx.net/forums/showth...657#post334657
I would also like to point out that [Annointed] still runs stock fuel injectors and stock fuel pump compared to WRXhellfire's Sti-injectors - he may even have uprated fuel pump.
My concern was how can anyone be rated as a good tuner if the economics worked in the reverse for their customers? For a merely 270 dollers, [Annointed] has achieved incredible bang for the buck - assuming the cost of the Utech is about the same for a Vishnu's Re-flash.
As regarding how water injection can be implemented safely, the discussion has already been started. Shiv might learn a trick or two from here if he could put down his Corky Bell book.
I have said enough...
peter head - observer
You have both surged ahead on my original question, rather spending a bit more time on the reason why Shiv couldn't make water injection work on his tune - you were providing solutions for what to do during or after water injection fails.
I would like to comment on your earlier reply on accepting Shiv is a good and talented tuner, but he prefers to leaving something on the plate and at the same time leaving his customer to pay the excess fuel bill for the years to come.
My immediate reaction would be Shiv maust have a very large plate. After seeing a gain of some 50-80 whp gain on 260whp from base line on [annointed's] tune against Shiv's 8whp loss tune on WRX-hellfire's 250whp baseline with water injection, he has left nearly 85-115 whp on his plate - extracted from the power chart on the other site.
http://www.clubwrx.net/forums/showth...657#post334657
I would also like to point out that [Annointed] still runs stock fuel injectors and stock fuel pump compared to WRXhellfire's Sti-injectors - he may even have uprated fuel pump.
My concern was how can anyone be rated as a good tuner if the economics worked in the reverse for their customers? For a merely 270 dollers, [Annointed] has achieved incredible bang for the buck - assuming the cost of the Utech is about the same for a Vishnu's Re-flash.
As regarding how water injection can be implemented safely, the discussion has already been started. Shiv might learn a trick or two from here if he could put down his Corky Bell book.
I have said enough...
peter head - observer
Last edited by peter head; Dec 23, 2003 at 09:35 AM.