BMW M4 GTS Comes with Water injection..Stock

[jmlegacy]

http://www.autoblog.com/2016/08/31/b...h-mass-market/

I'm curious to know what injector they used!

[mrx79]

Interesting article and video, even if it's an advertisement video.

But i'am interested, when you read most of the older tech papers from the WW2 era, they had much more benefit from having the injector prior the compressor or far away from the intake valve.

The Bosch system however is clearly an MPI system and it seems as if they go not for pre-combustion-chamber evaporation, but for in-cylinder effects only.

Would be interesting to know why?

If the WW2 technology not that precise then today's systems or do they want to avoid cylinder to cylinder deviations and using direct port for that reason?

[jmlegacy]

I can answer one of your questions.

I am convinced, even without evidence, that pure water does not vaporize as much in the intake tract as it would do with methanol. Water vaporizes easily under vacuum, and the opposite is true under pressure - harder to vaporize.

Yes I understand that boiling and evaoporization are different phenomenons.

I agree with BMW in injecting in the port with more even distribution of water

[Richard L]

This is a good find, thank you.

It took quite a bit of time before the major car makers how effective water injection is to a turbocharged engines. Very old concept. M4 will be the first of many to come. The setup is a constant pressure, PWM valve setup. In winter, water is drained back to the water tank by opening an inline solenoid valve after key-off.

I do not see methanol will ever be implemented due to its toxicity. Who know when the power race starts between makers.