Anybody has water injection system installed?

[bigtisas]

I read the discussion from the thread below and found a water injection kit ($170) on ebay.
Does anyone has a similar system installed on your e34? Does it work? Technically, with this system, I should be able to use 87 octane gas on my 525i and save money from buying 91 gas.

http://www.bimmer.info/forum/showthread.php?t=23997

ebay

[Macv]

Hmmm, I'd pass.

[nizmainiac]

works better with turbo'd engines

[bill g]

On a naturally aspirated engine you will probably lose power. I experimented with water injection years ago on a 351 Cleveland V8 (11:1 compression) and got no benefit from it.
I read sometime on DIY EFI forum (some real techheads on there) that the water mist or vapour will occupy space in the combustion chamber (therefore reducing space available for fuel and air) and contribute nothing to the combustion process.
Of course there are special cases where it is some use, such as on turbo,d engines.

Bill G

[92E34]

Water injection works best with Methanol or an Ethanol burning engine.

[Jon K]

Water injection is not a substitute for running shitty gas. You usually mix alcohol in the water and inject it when you're boost is higher to prevent knock by cooling the mixture. Running 87 on a car requiring higher would mean you want to inject all the time... these are like < 3 gallon containers.

There really is no purpose in injecting water on an NA motor since the intent of water is to alleviate temperature (compressed air) in forced induction setups.

Yes I have a water injection system sitting here

[BillionPa]

read my last post.. about proper calibration.

the amount of ambient moisture in vapor form is EXTREMELY hard to match for normal driving conditions with a water injection system, unless you are using some kind of ultrasonic injector.

if you want to save gobs of money on gas, switch to liquid propane.... OR use gas with no ethanol in it, and take a look at some of the things i have said about acetone in combination with ethanol free gas.

also, switching to 0W30 oil will save you additional money on gas, due to lower viscosities over the entire operating temp range.