Honda16hb

on that thread that I pulled up it doesn't talk about that, it just says to use the pressure switch, then scarecrowX who is ------- awesome sent me a bunch of schematics for car related ---- and the lm311 is used alot, it's just basically a switch that is adjusted for different voltages by your potentiometer. and I just now realized that I fucked up in my description. the map sensor signal needs to get to it somehow. I'll ask scarecrowX to explain since I'm lost and only thought I knew what I was doing.

scarecrowX

you want an electrical pressure switch you say?

what's in it for me?
heh, j/k.

lm311.

pin 1: ground
pin 2: map sensor input (use 10k resistor in series with sensor
pin 3: adjust input- use 50k potentiometer center pin (outside pins to 5v and ground)
pin 4: not connected
pin 5: not connected
pin 6: not connected
pin 7: output pin, 470 ohm resistor in series to center pin of power NPN transistor. looking at front of transistor, left pin is solenoid output, center connects to pin7 via resistor, right connects to ground.
pin 8: connect to 5v with 1k resistor in series

make sure you use a diode from the output pin of the transistor to 12v (the stripe on the diode canister will be closest to 12v). this prevents the lashback current generated when the solenoid de-energizes from damaging the transistor.

i'll draw a schematic when i have time.

quadnie

thanks for your contribution scarecrowX. If anyone wants to do an official fully functional HMT style Water Injection setup.. type writeup (pics would be nice too) I have no problem making it a sticky. Might even be tempted to do my own..

MR_DR_PEP

Na, I was popping the lid off when I wasn't using water injection just at 5psi boost. I put a check valve in the line to fix this problem...

BTW, I did some tests today with the water injection and wow... it's incredible. I've never seen my 3rd and 4th gears pull so hard! It actually scared me because the mixture made my car run too rich and the engine had a huge thud.. thought I blew it, but it was just too much fuel so I had to lean it out some above 7psi. I have a digi cam I can record videos with... I've got to show y'all the acceleration. I'm thinking with all this tunning I've done, 9psi boost, starion FMIC, water injection, and 2.5" straight exhaust, I must be pushing ALOT of power on this d16... it pulls much harder than my buds Z28. I need to take this to the track again with water inj. I was running 82 mph in the 1/8 mile track at 7 psi boost and no water injection.

I felt my chargepipes and intake manifold after fiddling with it today and they were very cold. I think water injection should be used on all factory turbo vehicles in everyday use. The only thing I'm going to fix now is the switch to activate under full throttle, and use a slighter more powerful pump.

Honda16hb

problem with factory water injection is most people won't bother or won't know how to fill up the tank and then the computer would have to limit boost, and in the 4 page water injection post it says that studies showed that it weakens the cylinder walls over time.

quadnie

Weakens the cylinder walls on what, an open deck block? I don't think it will harm a nice old fashioned sbc.

Oh yeah, for that switch you were talking about, having it under the acceleration pedal probably isn't the best place. Most nitrous kits I've seen (on v8s) have you place the switch on the throttle linkage, right by the manifold.. otherwise mounting maybe unstable. You could possible install it like a brake switch, somwehere up the pedal shaft.

Any ideas on how I can water inject my carb v8? I was thinking maybe buying a nitrous parts kit, and just using the under carb square that has the jetts for the NOS application.. then I would just work out the pump situation otherwise. Not like I have to worry about boost, and I have plenty of room under the hood to mount a spare resevoir.

Honda16hb

I don't think water injection on NA is all that great. the high temps of boost air help to vaporize the water so that you don't hydrolock your engine. I don't see how wear on floating sleeves would be any different than sbc sleeves, steel is steel, water effects both the same way.

Reddy

Water injection is only good for forced induction. The harm to the motor comes from people running alchohol in with the water. Alchohol has corrosive properties but this can be avoided with some mystery oil mixed in. A solinoid is necessary for a well functioning system.


Here's my little kit. I've found that Gordon's vodka has a little higher octane properties than Jim Bean.




Here's the pressure switch:

Honda16hb

I'm assuming you have the water injection on the twins, right? a solenoid can be used instead of the check valve, anybody know of any where to find one cheap?

MR_DR_PEP

ah! I'm getting ticked now. For some reason I keep getting that huge THUD above 5k rpm now with water injection above 6psi boost... It must be running really rich!? .. but ONLY with water inj. I'm going to get this thing right thurs. hopefully without blowing the engine. I put it in 3rd and take off with water inj. blasting and all of a sudden, THUD, at 5200... has anyone else experienced this huge thud when it runs to rich? I'm using STRAIGHT winshield washer fluid (the 89 cent kind) Stuff must be explosive or something. Can anyone explain why the THUD happens? I know it's obviously too much fuel, but I mean it feels like hitting a big bump in the road... can't be good on the motor. I'll just tune it out super lean at 5k+ 6.8psi+.