Thread: Water injection

Originally Posted by kreecha

I see some interest generated here concerning water injection, and when time allows I will post my complete install in the members rides section. For now I will just list the information and stats I have collected.

I have used a snow performance kit, and yes it does achieve a purpose, it is not however all that I am after; more on that later.

Firstly, I am using a snow performance kit. It is a stage 2 diesel boost cooler with a 60ml/min nozzle. I have my water pump mounted behind the passenger side headlight where a dual battery can be mounted. I have my injection nozzle mounted in the outlet pipe on the top tank of the intercooler. As the water reservoir, I initially used the supplied water tank, but at just over 1 liter it doesn't last long enough, so I am using the headlight washer hose from the windscreen washer bottle. This gives me about 5 liters useable water. I never use Metho it is too expensive. I have the adjustable controller set to start injection at 6psi. Full injection is programmed to be delivered at 19psi. My boost is only set at max 14psi though.

The purpose: the purpose that I employ the water injection for is dropping EGT's. On a recent Darwin-Brisbane return I collated some data as follows;

Between Avon downs and the NT/QLD border at 60kph @ 1230 the gauges showed the same EGT as doing 100kph @ 0200-0600 due to a 40km/h headwind. Boost was 4psi. Ambient temperature at 1230 was 36degC. At 0600, the temp was 20degC. (This was prior to water injection).

@ 100kph EGT 550degC block temp 97degC steady boost 11-12psi headwind dependent (strong headwind)

@ 100kph EGT 480degC block temp 94degC steady boost 9.5psi headwind dependent (small headwind)

I noted that a small ambient temp increase = large EGT increase.

With water injection I observed @ 105kp/h EGT 480degC block temp 92degC boost 10

A major positive that I also found is that not only does the water injection drop EGT's but it lowered my coolant (block) temps on average about 3-4degC. Mid-range boost was also slightly increased when injecting, but I would like a dyno run to prove it, this could be psychological.

Lastly; I need to address the system due to it's design shortfall's. If I do not prime the pump (suck water through the line) then the boost in the intercooler pushes the water past the pump and it runs dry. As soon as this happens I no longer get any injection. To overcome this I will fit a boost switch controlled solenoid between the pump and injection nozzle. I will set the adjustable injection controller to commence injection at about 5.5psi. I will then set the boost switch to open the solenoid at 7psi. This will overcome the pump-dry scenario.
I have the adjustable injection controller mounted under the passenger seat at the moment, but I will be moving it to under the bonnet.

I also have to increase my water storage solution because at the moment I use 5 1/2 liters of water in an hour at 100km/h.

I have found the initial outlay was expensive, but I have offset the cost because I used to use Cost Effective Maintenance de-carboniser religiously. Instead of the de-carboniser I now use the water injection to steam clean the inside of the engine.

Nice, what are you driving?

I want to install something like that but have my EGT sensor activate the water injection system only when the EGTs gets over a certain level, say around 450c. I figure this way it will only use water when needed which might allow 5L to last between fuel stops? I usually see temps between 350 and 480C at 100kph unless struggling up a hill where it can start to rocket up through the 500's.

Thanks for the info, its good to hear that you have found it effective at lowering coolant temp and EGT's. Lower temps is what I'm after!

Ahh,
I wondered where all my info got to.

Manic, I drive a S1 Disco with the 300TDI.

I think it would be a good idea to have the EGT sensor activate the water injection system because then the gains would be even more impressive, and the water usage would be directly linked to the load. (more load = higher EGT's).

However, going on your expectation of only using water when needed this way, I would be confident that 5L of water will not last between fuel stops. i have quite a large water usage, and was surprised with just how much was actually consumed.

I had a colleague in Darwin who had water injection in a D2 operated off of only boost, and around town (little load) he would consume 5L in about 3days, well short of the fuel tank running dry.

I see that you indicated that you see temps of 350 and 480C at 100km/h. Is this pre or post turbo? As you can see from my collated data my EGT's are a great deal higher.

I am, on a side note, internally cleaning my intercooler this weekend to ensure that it is not gummed up with oil, and rubbish therefore being as effective as LR designed.

Lower temps are a good thing and whilst I understand that 300TDI's do run hot, I know that the closer I can get the engine to maintain 89-93C the longer everything from head gaskets, p-gaskets, and anything in the engine bay will last. My experience with MTU's constructed similarly to the 300TDI has proven this.

I am pleased to see you appreciated the info, and if I have been a help then that is good to hear. As my system progresses in size and complexity i will be sure to post up my trials and triumphs.

Cheers, Adam.

G'day to all those watching this thread with interest.

As a quick update, I have spent a great deal of time considerIng what requirements I have of my WI system including that of the 300tdi, and what I can best build to suit my requirements, driving style and climate.

As a consequence I have recently purchased some equipment to expand the current configuration I have installed.

What I have currently installed;
Window washer reservoir - pump - 60ml/min nozzle.

I am currently experiencing cavitation with the pump, which is the snow performance ultra high output pump, and as I found, I do not have the integrated check valve. This means that the boost is pushing the water past the pump towards the reservoir, and as a result the pump cavitates. Not good.

The system I intend to build will incorporate a few ideas.
I will be installing a check valve between the pump and the nozzle designed to operate when the pump is activated from the standard progressive controller. This will hopefully stop the pump cavitating.
I will also be installing a tee piece in the system to run at least 1 extra nozzle. The second nozzle will be controlled by a boost switch and solenoid.

As for nozzle placement;
I Have the original nozzle mounted in the intercooler outlet pipe.
The second nozzle I intend to place in the system will be in the pipe work coming out of the turbo compressor housing.
The possible third nozzle I intend to use will be mounted pre-turbo, where I intend to spray directly onto the compressor wheel.

After much googling and study and also this informative post found here: http://www.aulro.com/afvb/1447718-post33.html this shows how heated the compressed air is discharging from the compressor wheel. I believe that a nozzle mounted in the pipe work from turbo will be beneficial for a few reasons including; water turning to steam may increase the effeciency of the compressor by (chemically/artificially) increasing the boost, water turning to steam will steam clean the inlet tract of the oil found in it (including the intercooler which is filthy inside!!), water turning to steam in this pipe will assist the factory intercooler.

Pre-turbo injection is understood to be very beneficial due to its ability to artificially make the turbo act as a bigger turbo.

Some of the considerations I have made in regards to the disadvantages to what I intend to do are;
The WI could pool in the intercooler,
The WI could make the factory intercooler less efficient,
The WI could WILL erode the compressor wheel.

Cheers, Adam.

what you need to do is use boost pressure from the turbo bleed point that drives the compensator and waste gate actuator to pressurize the storage tank install a carburetor like venturi after the turbo charger and then simply fit a small irrigation solenoid,.

Originally Posted by Blknight.aus

what you need to do is use boost pressure from the turbo bleed point that drives the compensator and waste gate actuator to pressurize the storage tank install a carburetor like venturi after the turbo charger and then simply fit a small irrigation solenoid,.

No that is not the way to go, if you intend to stay with the current system place a check valve just before your nozzle. If you intend to upgrade to 2 or more nozzles you will have to use solenoids especially pre turbo. You do not want any dribble pre turbo because that is what will destroy compressor blades. You will not really benefit from having an additional nozzle post turbo you will however gain a large benefit if you install a nozzle pre turbo. You wont however have much of a cleaning effect in the intercooler with straight water, you will need methanol for this. It will clean the engine well but not the piping or intercooler. Your turbo will not convert the water to steam if you install a nozzle pre turbo. It may occur with very high pressures, but unless you constantly run 15 psi + the air and turbo wont get hot enough to convert the water to steam, within 1 minute of your system activating the compressor cover will be cool to the touch. If you want the largest benefit from your system run water and methanol at 50:50, you will see a reduction of approx 100 degrees Celsius in your egts whilst boosting power by approx 15%. I run a combined 5gph in injected fluid but I could easily triple that for added performance but then it becomes costly.

If I was to advise on your install I would say use a 1gph pre turbo and a 3gph pre intake manifold. Start injecting at a boost pressure that is about 3psi above cruise and have 100% injection set at your current max boost.., use 50:50 methanol with tank or distilled water. Using that formula will give me about 1000k of hilly highway driving in a heavily loaded vehicle whilst using about 20lt of fluid.

I have a 300 tdi also.

Anyone worried about water getting past the pistons and ruining the oil?

Originally Posted by two up

No that is not the way to go, if you intend to stay with the current system place a check valve just before your nozzle. If you intend to upgrade to 2 or more nozzles you will have to use solenoids especially pre turbo. You do not want any dribble pre turbo because that is what will destroy compressor blades. You will not really benefit from having an additional nozzle post turbo you will however gain a large benefit if you install a nozzle pre turbo. You wont however have much of a cleaning effect in the intercooler with straight water, you will need methanol for this. It will clean the engine well but not the piping or intercooler. Your turbo will not convert the water to steam if you install a nozzle pre turbo. It may occur with very high pressures, but unless you constantly run 15 psi + the air and turbo wont get hot enough to convert the water to steam, within 1 minute of your system activating the compressor cover will be cool to the touch. If you want the largest benefit from your system run water and methanol at 50:50, you will see a reduction of approx 100 degrees Celsius in your egts whilst boosting power by approx 15%. I run a combined 5gph in injected fluid but I could easily triple that for added performance but then it becomes costly.

If I was to advise on your install I would say use a 1gph pre turbo and a 3gph pre intake manifold. Start injecting at a boost pressure that is about 3psi above cruise and have 100% injection set at your current max boost.., use 50:50 methanol with tank or distilled water. Using that formula will give me about 1000k of hilly highway driving in a heavily loaded vehicle whilst using about 20lt of fluid.

you use the pre intercooler air to pressurise the water tank, you deliver it post intercooler. then depending on the efficiency of your intercooler you're already in front of the game for delivery pressure.

The shape of the delivery mechanism after the intercooler needs to be like the venturi in a carby but if you want to get exotic you really need and induction ring setup like they use in the dyson bladeless fans.

Originally Posted by Brian Hjelm

Its other use was in high performance turbocharged aircraft engines in WW2. When a pilot pushed the throttle to Military Emergency Power, or "through the gate" as it was termed, water-methanol injection was activated. This acted as an extra intercooler (latent heat of evaporation) allowing the addition of extra fuel to the denser air charge thus more power. A tell-tale was activated under the cowling to tell the ground crew that a pilot had used emergency power. USAAF rule was that an engine used in this way had to be removed from service for teardown, inspection, and overhaul.

But the reality was a bit different. I worked with an ex WW2 RAF mechanic, he said they had no time to rebuild engines that had been pushed through the gate. They simply crimped new seals on the throttle and pushed them back out.

Originally Posted by manic

I'd be tempted to try it on a Tdi that has EGT issues on hills.

Then you need more boost and/or better intercooling, not water injection. It's that simple.

There is no such thing as "emergency high EGT". Either the tune is safe and produces safe EGT or it's not.