Preturbo water injection.
 

Has anyone ever heard of this? Why would it be done this way?

http://www.aquamist.co.uk/phpBB2/viewtopic.php?t=267

http://forums.nasioc.com/forums/showthread.php?t=922654

Holy shit thats a huge thread on the topic.

my head just exploded.

I do not believe it is possible to hurt a compressor wheel with a water injector spraying into the turbo. If the nozzle falls of maybe...........

If intercooled and water before turbo, the turbo outlet temp can return to ambient, then the intercooler is dead in the water. Can't cool ambient air with ambient air. No delta T.

Water after the intercooler can take a 90% effective IC and drop the temp to 20 to 40F below ambient, as the evap power of the water adds to the effectiveness of the IC, rather than subtracting from it.

The problem then is to run a pump with a regulator and enough pressure to be well above boost so it can be sprayed in between IC and throttle.

It can work marvelously, but never let it slip your mind that the safety is dependent on the water, and/or your ears.

What about this. Now that the post turbo water injection has lowered the temp another 20 to 40 degrees, how does the MS know this? After all it is relying on AIT reading for fuel calculations. Unless the injection happens before the AIT sensor.

Sam,

Air Fuel Ratio will tell you if you're misreading air temps. the AIT is a correction factor for air density. More air (cooler air) means more fuel. the true air temp reading is probably less important than the correction attributed to it. And that correction curve is usually adjustable.

A bit confusing but I think I understand.

Umm dont do Preturbo WI ok. WI needs frigin heat to work, if you spray into a cool part then your distribution and effectiveness will suffer. Most Sc'ers tha us pre SC WI do so becouse they want alil more rotor sealage and a lil rotor/case cooling. WI should be 4-8 inches from TB inlet and it should have the straighest route possible as suspended fluids do not like to make turns. As Mr. Bell has replied in this thread pre turbo WI will also result in possible water poolage in your IC and this is bad to.

Has anyone ever implanted the nozel directly into the intake manifold?

i now plenty people that did and had no problems with it. i am planning to upgrade to a dual nozzle sprayer and put them directly in the manifold.

First off, just because the air you spray into isn't hot doesn't mean it's not about to get hot. The water still stays in the charge when you spray pre-turbo, so when you do heat the air, the water in the air keeps everything cool. Not only do you end up with an ambient charge, you end up with an artificially high compressor efficiency, too. Also, with pre-turbo WI you ditch the IC because, as Corky said, no delta T = no cooling effect.

Yeah, My friends been using WMI injected right where the throttle body normally is on a 1.8 JRSC miata for about 2 months now. I tested the check valve that came with his kit to well over 30" of vacuum still closed so it takes a significant amount of pressure to open it. Seat of the pants gain was pretty incredible.

A WMI nut at the dyno shop recommended installing it post-compressor on the miata. His first kit on a Lightning netted like 30hp gain pre-compressor. On a whim, he tapped in right below the outlet of the compressor and saw like a 66hp gain. I've always read you don't want to pipe it in pre-compressor on a turbo, but never have seen any scientific data to back that. IIRC Coolingmist doesn't recommend installing pre-turbo.

I'd probably take what Corky said over anyone else in that subject, especially if you dont have a heat exchanger currently.

A lot of great info in this thread. Thanks guys.

Question so i dont have to make a new thread. Just as a heads up I searched through the first two pages and couldnt find a definitive answer.

Are we able to control water injection with the megasquirt or do we rely on the pressure switch that comes with the kit?

I haven't played with that yet so I can't give you any experience, but MS does have water injection trigger outputs. Joe Perez uses his megasquirt to control water injection, even used table switching for it too IIRC.

I remember reading that a while ago, some guys were trying to source some special controllers that could be triggered by the MS, there was some drama between two vendors. Am I remembering something remotely true?

Does everyone here with a MS use it to run the WI?

It isn't gonna work like u think sav. Go ahead and try it and u will see.

He's just rephrasing the links posted above. Thats not his theory.

Actually, no. I configured the MS for WI control, but never found the magic valve I needed to make it all work.

I am however using a pressure switch on the WI line to activate the MS's table switching input- this leaves the ignition map in an ultra-conservative setting until the WI lines comes up to pressure and switches it to the aggressive map.

I didn't see corky mention anything about pooling. Maybe there was an edit. And if it did pool, it would sure evaporate mighty quick.

That doesn't seem like a bad idea. I guess you want as much space to let the water work (time, really) as possible. What I do like about this is you don't get the situation where you're raising water pressure 5 psi for manifold pressure, but spraying across a 15 psi pressure differential because IC piping is at a higher pressure than the manifold.


My pet goal has always been to take a water tank, pressurize it from the manifold (with check valve to keep from putting the tank under vacuum) and a nozzle into the air cleaner from the same tank (bottom fed, obviously). The nice parts:
1) No motor or electronics or vavles* to worry about.
2) Fluid amount proportional to boost (assuming nozzle is appropriate)
3) Plenty of time for water to do it's thing

Cons:
1) Water tank "can" suck dry if too much vacuum, though there shouldn't be any
2) There's no real monitoring here, though you could add some.

Since I'm not worried about beating up the compressor, the basic idea sounds good to me.
*I've heard of people putting in an electric valve to close that off off of boost. I guess you could just run the system a bit and see if it empties at cruise, I doubt it would. Certainly any sort of a 1 psi valve would work, to keep it from dropping it's water.

It sure would be easy, though - if I could lose the IC piping and just run a water injection system and it would work as well, I would, no doubts.