just read a brief article on the Aquamist water injection system. Anyone have a list of the pros and cons of such a system on a 3rd gen? Is it really as effective as people make it out to be?



thanks,

kevin.

I dont know how effective it is but since installing water/alcohol injection on my FD I was able to find a small leak at the trottle body/intake elbow O-ring thanks to a small amount of water bubbling up. I cant tell any difference in power but I mainly did it as a preventative measure.

Pros and cons would be exactly the same for the FD as any other car. The Grand National guys swear by water injection and have been doing it forever. Here is another page about water injection and there are instructions on this page to build pretty much the setup I have.

very helpful link thanks!



kevin.

Yes, water injection works quite well at raising the detonation resisitance of your engine.



I won't go into all the details here but basically it makes you engine behave as if it's running on much higher octane gas. You won't really get much more power if you keep your boost levels the same. But you can safely increase your boost levels with less risk of detonation and in turn get more power.



The water also has cooling effects which helps power a little bit.



Make sure you add a little alchohol to the mix to prevent corrosion.



The downside is that if your water injection system fails or your water tank runs dry you will have engine damage. With a rotary you will almost certainly have total engine failure. In my experience most water injection systems tend not to be super reliable.

Pro's would be able to run higher boost, higher air/fuels, or higher timing with a larger margin for error. It gives you an area of safety, also cooling intake temps.

That is why I just added mine for preventative measure. I didnt tune for it and dont ever plan to tune for it. I wouldnt suggest increasing boost much (if any) over what can safely be done without water/alcohol because I dont want my engine life completely dependent on $200 worth of crap that came from a hardware store and wired up by yours truely. It is a good addition to reduce the risk of detonation and steam clean the engine internals while you are at it though.

i agree, i think it would be a good safety cushion but i wouldnt rely extra boost because of it

it might freeze up if you live in a colder climate, and cause damage

cant you do something to it so that when the water is gone, the pump will stop?

that isn't the problem. But yeah you could.



When the water freezes or runs out you detonate and blow up, thats the main CON of water injection

true. if it freezes........ it might even crack the container of water



but if you use the water injection just a precaution and not as something to add more boost then i guess you wont have to worry about detonating( or does it pump enough air , if you run out of water, to cause lean conditions)

Well I believe you add alchohol to keep it from freezing in cold weather. Basically you fill up the water at every gas fillup, its pretty easy to keep up with.

but if it worked great in the grand nationals......... i guess it wont hurt much .......... right?

Well when it runs out of water, thats it, its just out of water and not pumping air. Freezing and running out of water has never been a problem to those who actually use the system, at least I've never heard of that.

Well when it runs out of water, thats it, its just out of water and not pumping air. Freezing and running out of water has never been a problem to those who actually use the system, at least I've never heard of that. [/quote]

sounds good, im actually starting to consider it........ just another precaution to preserve my engine https://www.nopistons.com/forums/pub...#>/biggrin.png

another pro is that when the water is heated (absorbs heat), it acts like a steam cleaner for your engine. It will prevent and clean up carbon deposits that cause hotspots and eventually pre-ignition.



kyle

There were some factory Oldsmobiles in the 50s that came superchargred and had water injection. You were supposed to by a factory mixed alchohol/ water mixture that the dealer sold as "rocket fuel" for your water injection tank.



If you get a high quality and well installed system and you keep up with the water levels I guess you wouldn't have to worry about reliablity too much.



Or you could get a boost controller and run low boost levels on the street and then up the boost for the track w/ water injection...

the Aquamist is supposively the only reccommended water injection by anyone all the others are only thought of as decent.



I'm thinking this might be good for a situation like "rx73rdgen" described, allowing a higher boost to be run at the track while lowering fears of instant detonation.



Plus the steam cleaning aspect is a definite plus to avoid the carbon buildup.



I think water injection should be pushed a bit more https://www.nopistons.com/forums/pub...IR#>/smile.png



kevin.

Water injection is in my next to do list...once the 4.777 final gear/cusco diff are installed https://www.nopistons.com/forums/pub...R#>/tongue.png

has anyone tried water injection while spraying a wet 50 shot of nitrous?

keeping the boost at 15 psi.

i guess no one is crazy enough to try it https://www.nopistons.com/forums/pub...IR#>/smile.png

Probably because no one is crazy enough to run nitrous on an RX-7 period! I have heard of a few people running nitrous, but it is few and far between!



Tom -

How long have you been running your homemade system? Did you base it off of the DSM design on that site? Anything you needed to change to adapt to the 7? What boost level do you have the water injection coming on at? Did you run the pressure sensor off/near your MAP sensor? What did you use for a reservoir and where did you mount it?

I almost exclusively drive my stock 7 at lapping day events, and this could be a great "reliability" mod for my car.



Thanks!

Ryan

I've been running 19-21 psi on my motor now for a while with the auquamist system, I've done around 100 drag launches and around 200 hard pulls and my engine is currently still alive running pump gas. I'm very pleased with it.. I've also found that 1qt of water lasts a long time as well. We'll se if it can save my engine from the T70 I'm slapping on there soon enough... https://www.nopistons.com/forums/pub...#>/biggrin.png

Have you done any road racing? I'm curious as to how much water the system would use over a full day of 20 minute sessions, probably 8 or so minutes of each session being at WOT...



Ryan

actually it's a lot more common then you would think, heck one guy with i believe a TII is running like a 175shot or something, he's only on the other forum though. 50 and 75 shots seem to be a lot more common then you give credit for, and dont even say nitrous isn't good for rotaries cause then i'll have to find that guys page so he can teach you about how well it works if you know anything about nitrous itself.



kevin

but is it possible to run both nitrous and water injection?

i know that you don't gain hp from water injection, and that its only to reduce detonation.

so imagine you spray nitrous and water at the same time, isn't that going to send ice to you motor, or is it impossible for the temp to go below 32F?

water injection does increase tork at the same boost, but only lets you increase hp with more boost...



I don't see it getting that cold with the NOS.. I hate NOS by the way.. I want my power all the time every time and you can do that with the right turbo and no stupid blue bottles...

you set the water injection to come on at what ever psi you want, I have mine come on at 12psi... 1qt should last you all day, but it's going to depend on what size atomizing tip you use etc... It's not like you can't check in between sessions.. https://www.nopistons.com/forums/pub...IR#>/smile.png

Totally agree, but the car is packed enough as it is when going to the track, if it's going to use 5 gal of water over the course of the day, I don't think I have that much room in the car. Hmm, time to buy a track trailer... https://www.nopistons.com/forums/pub...DIR#>/cool.png



One quart on the other hand I have no problem with. https://www.nopistons.com/forums/pub...#>/biggrin.png

lol.. just use bottled water and not tap water since it is much cleaner and won't build up deposits in the water jet tip... I'm sure you can steal some from sombody at the track or maybe even buy it there.. https://www.nopistons.com/forums/pub...IR#>/boink.gif

I have been running my water injection for about 6 months in its current form. It started out as a Spearco setup and never really worked well. The stock pump is weak and you must run intake pressure to the tank to pressurize it, I never got it to work properly when set up that way. Now I have the pump and solenoid that are listed on the turbomirage.com site and am running that with the spearco tank and pressure sensor. In this pic you can see the tank on the right (where the battery used to be), the pressure sensor attached to it, the pump and the solenoid just to the left of the pump. http://tom93r1.freeshell.org/imgs/WI.JPG



I run a 50/50 mixture of distilled water and denatured alcohol. I dont remember the flow rate of the nozzle I used but my tank holds about a gallon and lasts 3-4 gas fill-ups with normal to slightly agressive driving. The pressure sensor is set somewhere around 5 psi but I need to wire a light bulb to it so I can verify when it is coming on. I put a "t" in the silicon hose to my boost gauge and ran that into the pressure switch.



After getting everything working I found I have a leak where the elbow and throttle body meet, water bubbles up through the o-ring. I didnt install it thinking it would be an intake leak detector https://www.nopistons.com/forums/pub...#>/biggrin.png



Installation is very easy, the instructions on that page apply to any boosted car you would want to install it on. Nothing special, just need to find a place to fit everything.

Found a site saying this about water/alcohol injection and reliability: (www.geocities.com/rad87gn/tech/alcohol.html)



Would that be better with a rotary engine, since it has a constant oil supply, worse, or a negligable worry either way?

no2 and rotarys work well together in small doses. Judge ITO has built a few n02 prepped engines. He seems to like it