water / methanol injection questions
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Just read some more, and again...
You /need/ the water/meth system following the injector duty cycle, not some sort of calculated duty cycle based off boost level, otherwise you won't be able to tune it.
Boost != IDC, any system not tapping IDC is not truly "progressive", and it will be close to impossible to tune it correctly, because AFR will be all over the place in different conditions (hot vs cold day, different RPM etc).Comment
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Are you sure you are not getting Methanol mixed up with Ethanol... Methanol evaporates virtually instantly taking the heat out the air at the same time, so little or nothing to do any damage to guides... Not compared to the amount of fuel that the inlet guides get washed with.Water injection works well with a good atomising injector post intercooler. Add Meth to it and watch your Intake guides wear out super quick as the methanol reacts with the phosperous bronze guides.
As an example 95% of the time only exhaust guides require replacement on 1.8t's the 5% the intakes need replacing too the cars have always run water meth. I've seen the guides so worn at times they are completely ovalled ready to break through.1986 Coupe q - 2281cc 3B, chargecooler, 2.75" exh & downpipe, ported head, water injection, CGR box, modified MD357 turbo, 440cc injectors, high power coil.
2004 A4 2.5TDi convertible, re-mapped to 180bhp
2011 A5 sportback 3TDi-Backbox delete, remapComment
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So to do the job right and run the water meth on an ongoing basis we need a progressive kit that can be tuned in sync with IDC such as the aqua mist system listed by PRJ.
Is IDC something that we can easily splice into in the loom or is there any inherent complexity involved? And what form does this signal take frequency / voltage / current etc?
Also to do the job correctly we're looking at a switchable chipset in the ECU. Maybe for clarity Paul could indicate the cost of adding a switched chipset to an already homefried ECU.
Then we're looking at a dyno run with say a standard ECU, a homefried ECU and a tuning session to optimise the WMI by running more boost and leaner. That's the only way to display any real gains.
The tank must have a level indication to signal the pump shutdown and switch over the maps.
Are there any other failsafes needed. For instance what happens if the tank has adequate fluid, the pump does it's thing but the WM doesn't get to the intake because of a broken fitting or a burst pipe. Has anybody any thoughts on how this failsafe could be impremented.
However before all that is done JP has indicated a very serious issue. From reading different sites they all claim to make the engine internals very clean so the methanol must be somewhat corrosive.
Is is possible that the management of the WMI is over supplying the mixture on those engines causing the damage or could it be that dislodged carbon particles are causing the damage?
The other thing I've read about WMI is that there should be a lubricant used. This feature seems to have been dropped by any of the commercial interests in this technology. Petrol contains some lubricant properties but a 50:50 mix of water meth would have none thereby diluting any of the lubricant from the petrol that would otherwise make its way onto the valve. Is it possible that the addition of this special lubricant would extend the life of the inlet valve guides?
MW50 article on wikipedia where the WW2 aircraft application is discussed.:
"MW 50 (Methanol-Wasser 50) was a 50-50 mixture of methanol and water (German: Wasser) that was often sprayed into the supercharger of World War II aircraft engines primarily for its anti-detonant effect, allowing the use of increased boost pressures.
Secondary effects were cooling of the engine and charge cooling. Higher boost was only effective at altitudes below the full-throttle height, where the supercharger could still provide additional boost pressure that was otherwise wasted, while the smaller secondary effects were useful even above that altitude.
MW 50 is something of a misnomer, as it is actually a mixture of three fluids: 50% methanol acting primarily to achieve optimum anti-detonant effect, secondarily as an anti-freeze; 49.5% water; and 0.5% Schutzöl 39, an oil-based anti-corrosion additive. The similar MW 30 increased the water to 69.5% and decreased methanol to 30%.[1] This increased the cooling performance but made it easier to freeze, the mixture intended to be used for lower-altitude missions. EW 30 and EW 50 mixtures also existed, which substituted methanol with ethanol; in emergency, pure water could be used."ShaneComment
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thats an interesting point. I wasnt aware of that and although i have mostly run water with a very small amount of methanol, i must see if this may have anything to do with the wear on my engine... we'll see.Water injection works well with a good atomising injector post intercooler. Add Meth to it and watch your Intake guides wear out super quick as the methanol reacts with the phosperous bronze guides.
As an example 95% of the time only exhaust guides require replacement on 1.8t's the 5% the intakes need replacing too the cars have always run water meth. I've seen the guides so worn at times they are completely ovalled ready to break through.
after that, water only it is!Comment
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To me any system like that is unsafe. No matter how many fail safes you install, the moment you run out of mix, or the pump stops working because of corrosion, or something goes wrong with the plumbing, will the engine be fast enough to reduce timing and save a disaster? If it is, is someone willing to find out?Just read some more, and again...
You /need/ the water/meth system following the injector duty cycle, not some sort of calculated duty cycle based off boost level, otherwise you won't be able to tune it.
Boost != IDC, any system not tapping IDC is not truly "progressive", and it will be close to impossible to tune it correctly, because AFR will be all over the place in different conditions (hot vs cold day, different RPM etc).
@ S2_wot: I have been running water (basically) on top of the map for cooling effect only, wasnt ever looking for huge extra gains, and it kept the car on a level base when running on hot weather. The additions for more timing and leaner mixtures would have a use on a drag race.
by the way, most systems use the WI while on boost, so heat soak is difficult to get rid of when driving casualy. Only a bigger intercooler would help there. If you end up wiring WI up to come up during specific injector DC, then you need a very big tank for WI and a very elaborate map to modify AFR on part throttle etc, unless you hook up a wideband and let that take care of both.(never seen it done, dont know if it is possible)Comment
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The amount you are squirting in is pretty miniscule in most of our applications (I am presently running a 0.4mm jet shared across 5 cylinders) and most of it is just vapour by the time it enters the combustion chamber so I think wear worries are a bit exaggerated unless you intend running a 1mm jet and a 80% methanol mix for serious dragster type boost and ignition maps.
Have done over 1500miles in mine so far and only used half the tank of mix from the washer bottle.
On the burst pipe front, if it did burst etc, the tank would empty pretty sharpish so would soon hit the low level switch before any damage could take place unless again you are running a dragster, or using a Merlin spitfire engine

Oh and mine only comes into play over 0.5 bar boost and is tied into the injector duty cycle too
1986 Coupe q - 2281cc 3B, chargecooler, 2.75" exh & downpipe, ported head, water injection, CGR box, modified MD357 turbo, 440cc injectors, high power coil.
2004 A4 2.5TDi convertible, re-mapped to 180bhp
2011 A5 sportback 3TDi-Backbox delete, remapComment
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Don't forget that motronic knock detection, retard maps, more fuel and boost reduction will still be in effect. The entire safety of the engine isn't being left to the WIMI controller.Paul Nugent
Webmaster http://S2central.net
Administrator http://S2forum.com
1994 S2 Coupe ABY - aka Project Lazarus
2001 A6 allroad 2.5TDi - family tank
2003 S4 Avant 4.2 V8 - daily burble
Purveyor of HomeFries and Exclusive agent for Samco hose kits (S2/RS2)
There are only 10 kinds of people that understand binary - those that do, and those that don't
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1986 Coupe q - 2281cc 3B, chargecooler, 2.75" exh & downpipe, ported head, water injection, CGR box, modified MD357 turbo, 440cc injectors, high power coil.
2004 A4 2.5TDi convertible, re-mapped to 180bhp
2011 A5 sportback 3TDi-Backbox delete, remapComment
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yes, but the loss of WI will be instantanious, and from 100+ octane (if you run high volume of methanol) you may end up in 96-97 at most of petrol. Will the timing be pulled that fast? Esp, from a motronic that in my case wasnt even hearing knock when i could listen to it?
All i am saying is that where sanity prevails usually these systems leave the AFR alone and dont go into changing those figures if you want to be 100% safe. With up to 20% methanol which i may have used at some point from a single injector (i think its 220cc) i didnt get the AFR any richer, and i never increased timing on it. What i did do, is adjust the timing with IAT which is what it helped, so as soon as the WI was cut off, timing could be pulled immediately. No knock was required to be 'heard' in order to pull timing, as this was directly related to IATs. That is something that motronic can easily do, and would be faster acting i suppose.Comment
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Searching for water soluable lubricant will bring you to websites that have very little to do with engines.. Beware
@A80avant, some examination of your inlet guides would be interesting. If the guide wear can be overcome then my idea is to use this system all the time however I don't cover the miles that you do.
As per earlier in the thread 13-15 litres should last a tank of fuel so a 20 litre tank is a minimum. IMO if the "system" as a whole isn't set up to work everytime the car is used then it's a waste of time.
If I can source a suitable kit I'll be asking Paul to turn everything up to 11 and then get a bigger turbo and do the same again.
@PRJ / Paul do ye think that a 20% gain could be found in addition to what a homefried setup will deliver.
I'm not worrying really, rather attempting to figure this out in as few attempts as possible.
Another benefit of switchable chipsets is the car can be warmed up on the standard setup and likewise run on the standard chip to dry out the intake before shutting down.ShaneComment
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that is true as you say, you may not cover those miles as i do.
Really wondering though, as i have driven the car in the greek weather/summer etc and with a big intercooler, there was never a big problem really. Even then i used the WI only on boost which kept the car in shape during the heat i believe!
ill report on the intake guides/valves
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You are obviously intending to use a more aggressive setup than mine as like I mentioned my 6 ish litre washer bottle is still almost 1/2 full after 1500 miles.Searching for water soluable lubricant will bring you to websites that have very little to do with engines.. Beware
@A80avant, some examination of your inlet guides would be interesting. If the guide wear can be overcome then my idea is to use this system all the time however I don't cover the miles that you do.
As per earlier in the thread 13-15 litres should last a tank of fuel so a 20 litre tank is a minimum. IMO if the "system" as a whole isn't set up to work everytime the car is used then it's a waste of time.
If I can source a suitable kit I'll be asking Paul to turn everything up to 11 and then get a bigger turbo and do the same again.
@PRJ / Paul do ye think that a 20% gain could be found in addition to what a homefried setup will deliver.
I'm not worrying really, rather attempting to figure this out in as few attempts as possible.
Another benefit of switchable chipsets is the car can be warmed up on the standard setup and likewise run on the standard chip to dry out the intake before shutting down.1986 Coupe q - 2281cc 3B, chargecooler, 2.75" exh & downpipe, ported head, water injection, CGR box, modified MD357 turbo, 440cc injectors, high power coil.
2004 A4 2.5TDi convertible, re-mapped to 180bhp
2011 A5 sportback 3TDi-Backbox delete, remapComment
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Based on water being cheaper and more effective than petrol as a coolant I'd use it in preferance all day long.
I've sent an email to aquamist with a few questions and will report back if I get an answer from them.
I mentioned earlier about using an aluminium tank. This is out of the question based on this document which details most aspects of methanol usage and storage:
ShaneComment
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i am going to install a WI kit simple and easy wit ha pressure switch not so much about the IAT but mostly for the cleaning effect in the combustion chambers. Water is what cleans the chambers and not methanol or something else.
If you want to use WI as a serious aid for power then you should go to port injection parallel in DC with the fuel injectors and not by simply installing a nozzle somewhere in the intake route. I remember seeing some WRC cars a couple of years back with ERL WI systems with a couple of piston pumps and port injection.Go Holset or Go RS4Comment
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