water injection

[Apache]

Thinking about this, but the popular (ie affordable) kit that uses a water pump from a mobile home, well, is it really that good?

One of my petrolhead mates has an RA Scooby with mods for 370bhp and uses a pretty trick methanol injection system (aquamist, I think). He tells me that lower pressure pumps dont atomise the water properly and you can get localised cool spots in the bores which is bad.

Any experts out there?

[NFC]

I know Saab used this nearly three decades ago to up their 145BHP turbo to 205BHP (more horsepower from 2 litres than a Sierra Cosworth, and nearly 10 years earlier), but I really would have to worry about putting anything incompressible (i.e. water) into a diesel engine, even in small quantities.

And it's no good unless you turn up the boost.

[Bikenuts]

Thinking about this, but the popular (ie affordable) kit that uses a water pump from a mobile home, well, is it really that good?

One of my petrolhead mates has an RA Scooby with mods for 370bhp and uses a pretty trick methanol injection system (aquamist, I think). He tells me that lower pressure pumps dont atomise the water properly and you can get localised cool spots in the bores which is bad.

Any experts out there?

Most nozzels are designed for 100psi, Sureflo pumps can be modified to produce this. I use a Sureflo pump with a 5gph nozzle, be sure to fit it after the turbo and you should be fine.

[BUSHWHACKER]

I though diesel didn't like water!

[Bikenuts]

Don’t be confused by people that only know about tuning petrol engines, diesels are very different; for example rich mixtures make petrol engines run cool but diesels hot and vice versa, so the extra fuel a petrol tuner may add as a safety measure might kill your diesel. Petrol tuners add relatively small amounts (typically less than %10 of fuel) of water mixed with up to %50 methanol to reduce detonation. Diesel tuners add a lot (typically %100 of fuel) of water with no or a little methanol say %10-%15 to reduce temperatures – inlet charge temperature, Combustion temperature and consequently exhaust temperature.

The system fitted to my Surf is intended to reduce the levels of harmful emissions to a level comparable to that of a small saloon car. The water injection system consists of; a water tank, a high pressure water pump, a control box, a nozzle fitted to the inlet manifold and associated pluming. The system is currently triggered by manifold pressure taking a piggy back signal from the MAP sensor but I’m hoping to convert it to be triggered by EGT if I can source a suitable amplifier for the thermocouple output. When triggered the pump sprays water into the inlet manifold through the nozzle, the design of the nozzle and pressure generated by the pump; about 100psi ensure that the water is vaporised as it enters the manifold cooling the inlet charge as it does so. The effect is to reduce peak combustion temperatures resulting in lower emissions of NOX and particulate mater. Under certain atmospheric conditions (high temperatures and low humidity) water injection may lead to an increase in output of as much as %15 with no other changes. However by reducing temperatures water injection allows you to add more fuel and boost without damaging your engine.

[TonyN]

I though diesel didn't like water!

Your not sloshing water into the motor, its just a way of cooling the intake charge. Cooler air =denser air =more oxygen =bigger bang =more power.

[BUSHWHACKER]

I know that, Duh!!

It just seems a lot of faff just to make a Surf go as fast as a CORR racer.

[Bikenuts]

Your forgeting the flowers and kittens saved by the reduction in emmissons

[Apache]

I know that, Duh!!

It just seems a lot of faff just to make a Surf go as fast as a CORR racer.

Probably a lot less faff than fitting an intercooler, with the similar effect of reducing charge temp.

[BUSHWHACKER]

Aiiee don't fink so.

[da SLUG man]

Your forgeting the flowers and kittens saved by the reduction in emmissons

and bunnies!!

[Apache]

Aiiee don't fink so.

Water injection doesn't require a new bonnet / scoop / bodylift :tongue2
:

[Apache]

uh-oh <smiley error>/

[metalmagpie]

Water injection

I have just finished fitting an SMC water injection system to my 2.4td. Easy enough job. I took out the nearside battery (you don't really need it so long as your other battery has 650A cranking ablility.) I bought an Iveco Van washer bottle which fitted almost exactly after I made a simple packing piece to make the top of the bottle horizontal) Wiring was fairly easy, needed a relay from an ignition circuit to switch the 30a the pump needed and mounted the control box in the footwell.
I used a 4 gpm nozzle tapped into the back of the metal box which takes the turbo charged air to the engine inlet. There is also a pressure sensor which controls the input rate. This I t'eed into the pressure sensor pipe from the turbo volute to the turbo controller.
It all seems to work OK, now to see if does any good.

[Terry Syd]

Water injection

I went through a long process to try and get my WI system working right. Unfortunately, I had a bodgey M3 nozzle that wasn't spraying right. I now have the system set up differently and it's working very well.

Here is the thread on the Oz forum - http://dahn.webcity.com.au/~toy49040...ic.php?t=15662

It isn't until the last page that I twigged to the M3 jet. I am now running a M1 pre-turbo and a M2 post-turbo. You can take a look at some dyno charts on that link to give you some ideas.

I am presently waiting for an extra check-valve to install in the pre-turbo nozzle holder. I want to eliminate as many large droplets of water as possible in the pre-turbo nozzle and the extra check-valve will prevent the nozzle from dripping.