I'm throwing in a turbocharger or supercharger in a few months and was wondering about water injection. I was wondering how much it would help when running a turbo/supercharger at 10 psi and if its even worth it unless you want to run higher. Would it help the engine have a longer lifespan etc.? And can you turn a water injection system off for cold winters? Anyways, I'm clueless on this subject so any info would help a ton! http://www.i-club.com/ubb-files/smile.gif

MN,

Here's the link to ERL's Aquamist water injection stuff - http://www.aquamist.co.uk/
They have some tidbits which could answer some of your questions.

You needn't turn off the system in the winters. Windshield washer fluid antifreeze can be safely used - even straight up (contains methanol - 50% or so). Rimmer is an authorized ERL dealer.

Rimmer's new kit uses an I/C. That, coupled with a high effeciency s/c (higher than Eaton's Roots type blower) apparenty is enough to deter detonation. Water injection may not be required. Talk to Robert (aka 'rao' on the board), he will be one of the first to get the kit. He's running a mailing list for those interested in Rimmer's new kit - http://www.onelist.com/group/superchargedsubarus

Ed.

Ed is right. Water injection is a neat idea and the Aquamist system is one of the best. The biggest problem is what to do if you run out of water, but that can be solved by onitoring the level in the water tank. You shouldn't need it for Rimmer's new system.

I am getting the first kit from them, but I have no idea when it will actually arrive. It should be soon, but I have been hearing that for quite a while now. As soon as I hear something definite, I will post it here and on the mailing list.

eddecker,
for you and me who are running the Eaton blower and no Intercooler, do you have any idea how the aquamist system would hook up and be applied to the Eaton setup?

TR,

It is actually very easy to hook up. You have a choice between the 1S and 2S systems. The 1S operates off of a pressure switch so when it sees a certain amount of pressure (which can be varied by changing the switch itself) the pump turns on, the 2s uses a MAP sensor and operates in 3d where you can vary the amount of water by boost pressure and rpm. The 1s sytem is a lot cheaper. YOu need a place for the water supply (or you can use the washer bottle) and you need to mount the pump. The water jet is rally small and you want to put it after the blower but as far before the intake manifold as possible. The Aquamist site has a lot of good detail about who to do it.

I agree with you, Shiv. It's a band aid - one that can work quite well, but still a band aid.

[This message has been edited by rao (edited April 30, 2000).]

IMHO, water injection is a band aid for a poorly tuned system. Water/steam isn't combustable and takes the place of gasoline which is. End result is a car that makes less power at the same boost pressure with extra complexity and potential for failure. So why not lower the boost instead? Of course, if you're system is knocking on the currently available gasoline, water injection may fix the symptoms, keep your engine happy and potentially improve performance. But good EFI tuning does the same thing while actually fixing the source of the problem.

I don't believe water injection belongs (ideally) on street cars running moderate boost levels. On a super high boost, small displacement, high-hp race car, crippled by restrictor plates, rules and regulations, it may have a place. For an 300-odd hp EJ25 running 92 pump, I don't think its the way to go. It detonation is a problem, I would suggest looking at the intercooler, turbo sizing, fuel/ignition tuning before considering dumping water into cylinders. The Brits, however, seem to love WI.

shiv

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