BMW: Water Injection Can Boost Power And Cut Fuel Consumption

[Daox]

Its been talked about a lot here, but I don't know anyone actually using it.

I imagine they're using water instead of enriching the air/fuel mixture which obviously can help, but only under high loads. I'd imagine you'd get more benefit from the increased compression ratio. Still, neat to see some numbers attached to it.

BMW: Water Injection Can Boost Power And Cut Fuel Consumption

This cooling effect can reduce fuel consumption by up to 8 percent, but also increase power by 10 percent, BMW says.

The carmaker also claims that water injection allows its turbocharged engines to use higher compression ratios, but still run on lower-octane gasoline.

With water injection added, BMW says it was able to increase the compression ratio of the 1 Series' 1.5-liter three-cylinder engine from 9.5:1 to 11.0:1.

[oil pan 4]

The compression bump alone will account for about a 2% power increase.
Here is a good hot rod magazine article about compression ratio. For once its not all about power, power and more power. They actually consider things that matter like low end torque and thermodynamic efficiency.
http://www.hotrod.com/events/coverag...ression-ratio/

Originally Posted by Daox

Its been talked about a lot here, but I don't know anyone actually using it.

Me and it worked.

[Daox]

You got a thread about it? I must have missed it, or forgot.

[oil pan 4]

I may never have made a post about it. I did make a wiki article about it.
Water injection - EcoModder

Here is the one on raising compression ratio.
Increased compression ratio - EcoModder
^this one needs to be updated, I hope my login still works.

[jedi_sol]

How is this different than HHO systems?

[UFO]

Originally Posted by jedi_sol

How is this different than HHO systems?

Because water does not dissociate when injected, it evaporates and cools the mixture, inhibiting detonation when combined with a high compression ratio.

No bottles and wires or power input required.

[oil pan 4]

Originally Posted by jedi_sol

How is this different than HHO systems?

Water injection systems use actual water. Simple water injection systems actually work on diesel engines, gas turbine engines and turbodiesel engines.
They can work on gas motors but to make it work requires some level of automation, computer controls and many hours dyno tuning time. You cant just add water to a gas engine and expect it to work like with the other engines.

HHO systems use a stupid idea that involves using 12v power to split water into tiny insignificant amounts of hydrogen and oxygen. This H and O are then fed into the engines intake air to produce no net gain.

The only thing they have in common is water.
They are completely different.
The main difference is only one of them actually works.

[oil pan 4]

Originally Posted by UFO

No bottles and wires or power input required.

Real water injection systems do require some power and therefor some wires.

[UFO]

Originally Posted by oil pan 4

Real water injection systems do require some power and therefor some wires.

I'm sure you know what I mean.....

[California98Civic]

Remembering to refill a water bottle with (I assume) highly purified water would be viewed by most consumers as a bigger pain than high octane fuel. And the cost savings in fuel would be at least partly offset by the cost of such water, wouldn't it? Why is BMW interested?