Water or Water/Methanol Injection DIY

[06YarisRS]

DISCLAIMER: The following only represents my current understanding and, as such, may not be fully factually accurate. I welcome correction or elaboration as appropriate.

I have been experimenting with adjustments to my part throttle, partial boost AFRs. Unlike a standalone ECU, the AEM F/IC does not have any true closed loop fueling capability. More on that in a minute. The car's factory ECU will fight to bring the AFRs to around stoich (14.7:1) largely for fuel economy. The F/IC will try provide a more rich AFR to compensate for the increased heat and cylinder pressures associated with ramming in more air and fuel - bigger explosions - and this is done by increasing fuel percentages in the cells of the fuel map. Once the throttle is depressed far enough, probably 90%+, the car will transition into open loop, no longer taking into consideration wideband O2 inputs, revert to pre-defined fueling maps, and allow the F/IC control over fueling. In this state, the AFRs become rich - in the area of 11.5:1 and the engine is in a safer operating mode. It seems counter intuitive; more power output, yet safer for the engine.



Although my car could be considered a low boost application, there still exists, however slight, a chance that knock could occur on, say, a really hot day, high engine temps after hard driving and increased cylinder pressures under 'high' boost, low rpms where there is the greatest stress on connecting rods, bearings, pistons etc. The 2ZR-FE engine has a compression ratio of 10:1 which is high to start with in a forced induction application (many engines built for FI are in the 8.0:1 - 9.0:1 range. So, in the interest of safety, I have been pursuing AFR enrichment in the part throttle, partial boost zones.

I have a couple of options:

Option 1: Attempt to "spoof" the O2 sensor signal in the F/IC tune map. The F/IC has the capability to basically trick the car's ECU into thinking that different AFR's - in this case richer ones - are stoich AFRs. The O2 sensor might pick up a ratio of 12.5:1 or 13.0:1, for example, but the F/IC will intercept the voltage signal and send the message that the O2 sensor is seeing 14.7. This works fine, except that the ECU will eventually get wise and start to trim out the extra fuel. There is a process to collect fuel trim data which is then put into the fuel map as percentage increases/decreases. This apparently completes the fueling charade and the ECU remains happy. Below is what I have so far. I've also included a table of what typical wideband voltages should per AFR. You will see that my numbers do not coincide, but I have managed (at least for the time being) to improve AFRs significantly in the partial boost areas. Now I am getting approximately 13.5:1 (2 - 4 psi boost), 12.5:1 (4 - 6 psi boost) and 11.5:1 (7 - 8 psi boost, when throttle position, I believe, puts the car into open loop).

My current O2 map:



Typical voltages from O2 sensor for different AFRs:



My current issue is this: I have not been able to accurately establish AFRs associated with each voltage adjustment as my Wideband AFR gauge fluctuates a bit during experimental voltage inputs. If I can't iron down steady values, I won't be able to put accurate fuel percentages in the fuel map cells. Should this approach not yield stable and predictable results, long-term, there is Option 2. But so far, it's working very well. Actually, I may go with both options.

Option 2: Install a water, or water/methanol injection system. I am leaning toward water only injection and here's why. If I can't tame the AFRs via the O2 map (reconcile the fueling in a way that the ECU doesn't get wise), the ECU would trim out any additional fuel (methanol) along with the gasoline. The O2 sensor and ECU will not detect an AFR enrichment with water only as there is no fuel component. Since, I'm not looking for power increases, but rather just greater safety (in the form of increased "effective octane rating", which water will supply), water seems the way to go. Theoretically, there would not be a power loss associated with injecting water as water expands forcefully as it converts to steam (steam engine effect). It simply dramatically drops cylinder temps, due to latent heat of water vaporization. Theoretically, a cooler more dense charge also permits more air and therefore, more fuel, but I doubt this will come into play as I'm injecting post MAF sensor.

If I go for option 2, water injection, I will be building my own system based upon what others have done and presented online. It will be a 'single stage' system, boost pressure triggered. I will experiment, but expect it to start injecting around 2 - 3 psi. I have already started to collect parts.

This is a seemingly very well built pump. It looks identical to the FlowJet pump in every way (rebadged) at $30.00 vs $95.00. I made a contact with an alternative energy company and they directed me to quality Chinese made pumps, vs the $20.00 eBay pumps. This has a completely sealed motor, unlike the cheaper open motor units on eBay. The pump is remarkably solid and surprisingly heavy and much quieter than I had expected. It is adjustable from 17 - 100 psi. It also has a built-in check valve and methanol compatible diaphragm and seals - in case I do decide to do a 50/50 water/methanol mix.

I would mount the pump on the passenger side front crumple zone frame section. It may require the fabrication of a mounting bracket - likely a flat aluminum plate.





Some fittings from McMaster-Carr. I bought three different nozzles for experimentation purposes. I also picked up a check valve which I'd placed close to the injector. I don't want water drawn into the intake under vacuum conditions. These misting nozzles meet the same specs as the very expensive 'made for water/methanol systems' nozzles that retail for between $60.00 - $75.00 CAD with shipping.



EDIT: It occurred to me that the check valve I ordered won't work. It cannot stop water from being sucked into the engine under vacuum. The check valves that are used in W/M injection systems are specially designed with a spring that has a pressure rating of around 16 -20 psi. So, I picked up a water solenoid.



I still need to source many other parts including a low-pressure (2 - 10 psi) Hobbs switch, tubing, fittings, a relay, fuse and fuse holder (may have one on the shelf in the garage already) a tap adapter solution for my windshield water tank as I'll be drawing off that. A few advantages of that are: it already have a level sensor, built in, it takes up no additional space and I don't want to give up hatch space, run wires and tubing through the car etc. If I go with water/methanol, many run winter windshield washer fluid, though there's much debate about that. There is a local agricultural business that will sell me straight methanol at $5.00/gal.

There is another option for triggering the system on. The F/IC has a switched 12V auxiliary power option based upon variables such as manifold pressure, TPS postion and rpm. In theory, I would just have to set TPS and RPM at low values and MAP at 17.7 PSIA (14.7 + 3 boost). I will experiment with this before searching for a Hobbs switch.

Hobbs Pressure Switch



Under Construction....

[06YarisRS]

Water/Methanol Injection...more parts arrived

2 days delivery from Ohio to a remote location in New Brunswick, Canada. Outstanding!

I ordered three nozzles for my experimentation purposes. The largest nozzle, #5 (3.16 gal/hr) and would be used between the MAF and throttle body if I use a water methanol mix. I would use nozzle # 2 (1.26 gal/hr) between the MAF and throttle body if I only inject water.

The third nozzle, nozzle #3 (1.9 gal/hr) may be placed post intercooler, well before the MAF, or in the turbo intake tube (Cold air intake). This is only if I go water-only injection. I have been doing lots of research and although it is not recommended to inject post-turbo and pre-MAF, many people have had success cooling the intake charge considerably using this approach. If I inject pre-turbo, there are significant benefits as well, providing that it is a very fine mist (virtually evaporated) by the time it hits the compressor wheel.

Package contents:





Nozzles and check valve. I will use the check valve in conjunction with the water solenoid for a little additional protection.





Going out today to the local hardware stores to pick up a bunch of fittings and nylon tubing or fuel injector hose. Once I get everything mocked up, I'll do a video of the nozzle spray patterns and link it here.

[CrankyOldMan]

McMaster is good like that--basically overnights stuff to me if I order early enough in the day.

Good catch on the check valve. The highest cracking pressure I could find on McMaster was 4 psi and they were all crazy expensive. Any chance you can disassemble the valve you got and put in a stronger spring? You'd have to find the right one by trial and error, not sure if you can get a selection of springs locally or if you'd have to try and order a bunch from McMaster.

[06YarisRS]

Originally Posted by CrankyOldMan

McMaster is good like that--basically overnights stuff to me if I order early enough in the day.

Good catch on the check valve. The highest cracking pressure I could find on McMaster was 4 psi and they were all crazy expensive. Any chance you can disassemble the valve you got and put in a stronger spring? You'd have to find the right one by trial and error, not sure if you can get a selection of springs locally or if you'd have to try and order a bunch from McMaster.

I frickin' love MaMaster-Carr! Amazingly friendly service, great prices, huge product selection, knowledgeable staff (from my first experience). And, yeah, that shipping time...awesome! From my limited experience, it seems they set the bar.

Actually, I think the check valve is going to serve it's purpose in this way. The water solenoid will protect against unwanted injection when the engine is running, the check valve will keep fluid from heading toward the motor when the engine off. I think the crack pressure of this valve is only about 1 psi. I also wonder how much vacuum is on the intake side of TB butterfly at idle. Maybe enough to siphon, but, again, I'm hoping that the solenoid gate valve looks after that. The above said, I plan to test the system extensively before it gets operated on the car. This is SO much fun!!! Haha. BTW, I'm pretty sure that typical water/methanol check valves are in the 16 to 20 psi crack range. My pump only does 80, haha, so it should be interesting to see what kind of pattern and volume I get out of it.

Question for you, Sam...

Since I'm not looking to gain any power here - simply provide a higher effective octane number - in your opinion, is any amount of water injection helpful? For example, if I couldn't meet the full recommendations of load/boost etc water volume, would lesser amounts still help to some degree? I'm not sure that it's a truly linear relationship, or if there is some kind of minimum needed to have any effect.

[06YarisRS]

More fittings...

Our local automotive supply shop did have some of the more common items I need. I'm pretty much set up now to install the injector before the throttle body. Bonus is, is that I don't have to weld a bung on the charge pipe! I can just drill the appropriate size hole, insert the nozzle from inside the charge pipe and sandwich it on with the fittings. Not that it's super high pressure, but I'll pick up some fuel injection clamps or dig through my misc parts box for some spring clamps to secure the hoses to the pump barbs and nozzle barb.

Next is to get a 3/8" tee and decide where to place the secondary nozzle.

Fittings and high pressure fuel hose:

[CrankyOldMan]

Originally Posted by 06YarisRS

Since I'm not looking to gain any power here - simply provide a higher effective octane number - in your opinion, is any amount of water injection helpful? For example, if I couldn't meet the full recommendations of load/boost etc water volume, would lesser amounts still help to some degree? I'm sure it's a truly linear relationship, or if there is some kind of minimum needed to have any effect.

That's all way out of my wheelhouse. I've never done tuning before, just slapped the Blitz on my 1NZ and called it a day.

[06YarisRS]

Originally Posted by CrankyOldMan

That's all way out of my wheelhouse. I've never done tuning before, just slapped the Blitz on my 1NZ and called it a day.

Yeah, well I'm learning a lot. It's interesting, but sometimes I wish it was simpler. Haha.

[06YarisRS]

Slowly collecting parts

Today my water solenoid arrived. Of course, I ran right out and tested it on the car battery. Also, picked up a 10 amp fuse holder and fuses.





Turns out that the pump I picked up isn't pressure adjustable after all. It stalls out at around 30 psi. The injection nozzle is too small and it overcomes the pump. I am returning this one and have ordered a slightly more robust pump. The one I currently have is rated at 35 psi. The new one is rated at 100 psi. 100 should be more than adequate. I hooked up my hose and nozzle to the garden hose which produces about 35 - 45 psi and it worked great.

Here's the new pump I ordered. Not bad for $51.00 Cad shipped (with $3 Amazon rebate).

[CrankyOldMan]

"NOT PUMP FLAMMABLE LIQUIDS" =D

[WeeYari]

Originally Posted by CrankyOldMan

"NOT PUMP FLAMMABLE LIQUIDS" =D

I've lost track. Is he pumping water, meth, or blend?

[06YarisRS]

My intention is to run water-only injection. This way I don't have to do any fuel mapping. I want to try a dual injection setup. 1 injector in the normal place between MAF and throttle body and 1 either before the turbo itself, or just after the intercooler. I should be able to get a pretty good effective octane rating this way. I wouldn't want to spray methanol across the MAF sensor even in a gaseous state. The injector nozzles create a very fine mist, almost like a fog. I expect that the mist will be pretty much evaporated before it even hits the MAF sensor. This will cool the air charge making it more dense and the ECU should add some extra fuel. Putting the nozzle before the turbo also, apparently, increases the density of the air through cooling and increases the efficiency of the turbo. Of course, the pre-throttle body nozzle will basically inject mist into the cylinder and it will work its magic there cooling.

I did some metering of the water volume via my garden hose which is around 40 psi. The specs on the nozzles are pretty much bang on. I also solved my pump cycling problem. I bypassed the pressure switch. The pump stalled out at 160 psi (powerful little pump)! So, I can use this pump and set aside the other one I ordered as a backup. I plan to get a ball valve and set up a return cycle system - back to the windshield washer tank. I can adjust the ball valve so that the pump is making whatever pressure I want. I'm thinking about 40 to 50 psi would be perfect. The nozzle that is currently on there is a M5 (0.5 mm orifice) and puts out 3.2 GPH at 40 psi). This would be almost the exact amount I'd need if running a 50/50 water/methanol mix. However, you inject about the half the volume if using straight/distilled water. I have two other nozzles M2 and M3. I think I will try the M3 pre-turbo (or just after the intercooler) and the M2 at the throttle body. I may have to reduce my pressure a bit or order another M2 or even an M1 nozzle. Obviously, some experimentation will be necessary. It should be interesting to observe/compare both the IAT and EGT with the system on and then the system disabled.

Don't laugh too hard, but I tested my theory (with the help of my daughter). She loved getting all wet! I just punched some holes into the hose that I have the gauge teed off on. The pump will run very solidly without labouring even at the approximate 70 psi I had achieved. This is way more water than I'd inject, but if I use the ball valve to maintain about 40 psi, the flow and volume should be near perfect.

Here's a video:

Check out the pattern and atomization. Using the smaller nozzles, even at lower pressure, should give similar results. Not bad for $7 - $8 a pop at MacMaster-Carr vs Snow performance or AEM at north of $50.00 each (in Canada).

https://www.youtube.com/watch?v=CnDD8cCgukQ

All of this is just based on research I've done, but it might end up being a gigantic fail. Hopefully not. Haha.

[06YarisRS]

Mock up and test of water injection system

Once again, living in a semi-rural area, I had to make due with typical hardware store fittings, plus what is in my misc fittings boxes. However, so far I have, I'd say, just over $100.00 invested. I'll be into another $50.00 or so if I go for a hobbs pressure activated switch. I haven't tried the switched 12V output from the F/IC yet, but will give that a go soon. I also have to get a little LED light for the dash to tell me when the system is active. I'm guessing I'll know as I'll likely hear the pump. LOL. The camera really seems to amplify the sound as it's not that bad in person. Plus it's rattling everything it touched including the big pot I'm using. The pump will be solidly mounted to the chassis on a rubber pad so hopefully it won't be too obtrusive. When my more powerful backup pump arrives, I may try that one.

This system will be more than capable of delivering the desired amount of water/mist. The pump easily does 50 psi and I can simply dial it in with the by-pass (ball valve)

Videos:

https://www.youtube.com/watch?v=oOhFq2RYRI8

This video gives a better idea of the pattern, despite being a bit breezy out.

https://www.youtube.com/watch?v=u_5BIbZXWfY

Video Added. Nozzles mounted in section of old exhaust pipe. They will be placed in different locations in the system. I hooked up the shop vac to see a simulation of what the spray will look like with boost, or I guess vacuum, in this test scenario. I'll see if I can reverse the vacuum and blow through.

https://www.youtube.com/watch?v=Xy6jnCzlDI8

[06YarisRS]

Injection controlled by AEM F/IC

I fiddled with the F'IC today and have it dialed in to trigger the injection pump at around 3.5 psi.

https://www.youtube.com/watch?v=FiQ8T7Ybq54

[06YarisRS]

Proposed Wiring for Water Injection System

This is a modified diagram from the site I used to build my system.

http://www.turbomirage.com/water-alc...tructions.html

Please feel free to check my wiring and weigh in. I'm wondering if I should move my "Master Switch" from terminal 85 wire over to terminal 86 wire.

[06YarisRS]

A few extra parts

Picked up what should the last of what I need to complete the water injection system.

- new pump
- relay and harness
- master rocker switch with blue LED
- green LED pump operational indicator light
- inline fuse holder and fuses
- female blade terminals

[06YarisRS]

Installation Starts

I got the pump mounted. I made a small bracket from aluminum plating I had lying around. In my junk drawer, I got lucky and found exactly 6 carriage style bolts and nuts. The pump is very solidly mounted and I put foam rubber between the plate and the chassis to help reduce noise. I decided to use my new, more powerful pump and I'm glad I did. It is SO much quieter than the smaller one.





I had to drill out the rubber feet mounts for the larger carriage bolts.



Pump Mounted





Pump is mounted well below WW tank and will be a very short, almost vertical run down to the pump. I'll install a filter between the tank and pump.



Since I have two extra nozzles, I think I'll double up the system as an intercooler sprayer as well. I had thought about injecting before the turbo or after the intercooler but I'm worried that it will adversely affect the MAF readings. Yesterday, after a sprited run, I decided to see what would happen if I misted the intercooler with the garden hose. I was amazed at how quickly and significantly, the intake temps dropped and that was with car idling and with larger water drops. I think the fine mist generated by the nozzles will work very well, especially when the car is moving and it goes through the intercooler fins.

[suprf1y]

Nice drill!

I've built a number of these systems and I never liked the idea of a fixed output. As RPM, load and HP increase, more water is required to do the same job.
So the last few I put together I used an automotive fuel pump and injector, machining a block with a boost referenced pressure regulator installed to return to tank, and a simple 555 timer chip based extra injector controller. It worked really well increasing pressure (injector flow) as boost increases and pulse rate with RPM. Aside from being able to choose the ideal injector sizing, with the injector controller circuit you can also increase and decrease the pulse rate based on the RPM input. Your AEM may even have a usable output for that.

[06YarisRS]

Originally Posted by suprf1y

Nice drill!

I've built a number of these systems and I never liked the idea of a fixed output. As RPM, load and HP increase, more water is required to do the same job.
So the last few I put together I used an automotive fuel pump and injector, machining a block with a boost referenced pressure regulator installed to return to tank, and a simple 555 timer chip based extra injector controller. It worked really well increasing pressure (injector flow) as boost increases and pulse rate with RPM. Aside from being able to choose the ideal injector sizing, with the injector controller circuit you can also increase and decrease the pulse rate based on the RPM input. Your AEM may even have a usable output for that.

Haha, you like the old Sears drill, eh? She's an oldie and doesn't even have reverse. Lol.

Yeah, I looked at the progressive systems and it would be ideal. My thinking here is that all I'm looking for is a little bit of extra protection during the partial boost, partial throttle stages. I have the F/IC set up to kick the pump in at around 3 psi. It will cover 3 - 7 ish psi and then the enrichment will look after the higher end. Once I'm up close to full throttle and in open loop, my afrs are in the mid to low 11s. What you did, I would love, but it's a bit beyond my skill level at this point. When you mention a 'useable output' from the F/IC, do you mean like a variable voltage output that could control the motor speed. I did inquire with AEM as to whether or not their progressive controller - that comes with their kits - would work with any pump. They told me that it would not as the pump is pwm controller.

Do you think my system will work? I am injecting water only through the M3 tip, pre-throttle body. I read that one only injects 1/2 the volume if using straight water as opposed to a 50/50 methanol mix. The M3 nozzle is rated at 1.6 gph @40 psi, or ~ 100 cc/min. I followed the recommendation that water is injected at a rate of 0.5 cc/hp. I have also figured out the rigging to easily plumb either one or two nozzles to spray on my intercooler. I just have to fabricate a couple simple brackets. The location is nice as it will also mist the rad and A/C condensor. I hope this is a good idea. My intention is not to advance timing or gain power in any way - for now. I just want a little extra security for the closed loop boost stages, especially on hot days.

I am proceeding with this setup, but I'd appreciate further thoughts from you if you're so inclined.