Hi, this would be my first post in the 3rd gen section. My 93 fd is currently in for a motor install. Mods include, Apex boost controller and fc with hand held, after market intake and exhaust all the way back, no cat or air pump. Stock mount after market intercooler, 550 cc primaries, and 1300 cc secondarys. After rebuild I will have a street port with stock non sequencial set up. Here is what I want to know, from anyone with experiance with these systems. I am looking to install water injection, but have received a very lukewarm endorsement of the concept from the guys who are rebuilding the motor. I don't want to mention the shop by name, as I am not sure that would be appropriate, however you would all recognize the shop. Please!! only those who have actually had experience with either CoolingMist's products or an equitant water injection system on a rotory. I am told there was a group buy previously on this forum, so I hope to get some good info. I will be traveling for the next few days, but will check for responces when I get back home and look forward to any info that you can offer. Thanks

 

I built my own very similar to the coolingmist, it can really do wonders for keeping the intake temps down. When I have it turned on I also see a definate reduction in the knock reported by the PFC during/after hard pulls.
I would not tune for water injection because of the consequences if it fails, I also wouldnt say I can tell there is any more power with it in. But the idea of preventing detonation and saving an apex seal is to me worth the couple hundred $ that it will set you back.

There are also many threads on water injection so a search will turn up some more good info.

 

http://www.aquamist.co.uk/phpBB2/index.php


and

www.waterinjection.info


These are the 2 main sites I used when researching my water injection. When running properly, I notice 5 to 10 degree Celisus drops in temp under full boost.

 

5-10? I got about 34C drop this morning. After fully warmed up cruising down the highway I was at 59C, got on it with water injection going and temps plummeted to 25C on the PFC. I think I may still have too large a nozzle though, sometimes I get a slight bog when I let off then cruise lightly for a few seconds after the water has been running.

 

Water injection is a great mod, one I'm surprised every heavily modded FD isn't running. The CoolingMist kit is good, David will take care of you.

I don't understand why your engine rebuilder doesn't think it's a good idea. It lowers intake temps, cools the combustion temps, keeps the engine cleaner, and reduces the chances of detonation. The only downside is the inconvenience of finding a place for a large pump and water tank.

I'm running a CoolingMist kit with a slightly unorthodox setup -- more information to come soon!

 

Rynberg how do u have your water injection system setup? Like does it come on at a certan temp? or throtle postion?

 

Check out www.coolingmist.com It uses a pressure (boost) operated switch.

Once I get a small problem sorted out, I will be posting a write-up on how my kit is setup.

 

Hey, where the write up at?

 

Get off your soap box!

 

i recomment Water Injection System to all rotaries!!!!!

i use this system

http://www.pinz.net.nz/

 

I'll be getting a WI kit from David for both my FC (centrifugally supercharged) and the FD fairly soon. From my research, there seems to be no reason NOT to run WI. Here in Florida, even with a FMIC, my intake temps will climb upwards of 50C (if not >60C) when I'm doing a lot of around-town driving (rather than interstate). Also, my traps at the track suck because of high intake temps. Hopefully, the WI will help all of this, and if it only helps prevent detonation, it was still <$300 well spent.

 

I pieced together a similar dummy WI system like coolingmists (used their reservoir) i.e. can't be mapped for a water to fuel ratio, either OFF or ON or ON two stage. WI is a great thing as stated, David (Zerobanger, for those who remember) does all the leg work for you as far as not making 6 trips to the hardware store for brass fittings and getting all the parts in one stop, great prices...

I have a SMIC and a single, and water is almost a must have.

 

I think a good point was made - the car should NEVER be tuned for water injection. If it's used as an extra to get intake temps down, it's a good thing. But, the car should be able to safely run without the water injection.

I can understand why the shop would be hesitant about it - many people have used water injection as a band-aid for poor tuning or poor fuel system setup.

Dale

 

Thanks Carson,
I think I am going to bite the bullet (again) and get the coolingmist setup. But I am not sure which one would be better for my application

 

I have built my own w/i setup folowing turbomirage.com website and when I build it I had a pettit racing ECU w/unlimitted chips on.
With stock injectors and IC I boosted about 18-19 psi with a boost spike of around 20+ psi on stock twins (non-seq) , that was kinda crazy out of me but I wanted to see how good the W/I performs, I boosted that psi bunch of times with no ill efects..., but now I got an untunned PFC so I can't do that till I get it tunned.

So, H2O is gooood,...

 

If you want to buy a coolingmist water injection i would check ebay. They had a good deal on there when i got mine. But i called them and they put a hole package togather for me and made me a good deal.

 

Unless I am missing something, it’s my understanding that it's the exact opposite. I don't understand the concept of running water injection without tuning for it, I don't see the benefits. Because from what I understand, adding WI is going to lean out the a/f mixture, so why should the car not be tuned for that? I would think not tuning for WI is a bad idea based solely on that rationale. Likewise, running a car tuned for WI and then going without water for a period of time is just going to cause the car to run richer. Something I don't really see a significant problem with.

Unless I am completely off and not taking something into account, I would think that makes sense. In which case someone please correct me. I currently have a WI kit I was contemplating selling based on my logic, however if it’s flawed I'll likely keep it.

 

Definetly flawed

The water mixture that gets into the intake is such a small amount, and is in such a vaporized form that it does very little, if anything to your fuel mixtue.

You can tune for water injection. the problem is that water injection systems are not reliable enough to take a chance on having it go out. I have an aquamist 2S system running in my car, and it actually has a way to run a sensor that will cut boost if it detects no water flow. When I am comfortable with the reliablity of the system, I will hook this sensor up. But for right now I still have bugs to work out.

Again, I urge anyone who is adding water injection to check out this forum for info. http://www.aquamist.co.uk/phpBB2/index.php it was an invaluable source of information when I was doing research.

 

Interesting. I have 2 questions.

Based on what you said, so long as the jets are properly sized, I should be able to just install the WI kit and go. There is no need to go back to the dyno to check AFRs or anything like that. Right?

Also, if I were to order David's Dual Stage kit, which two sized jets should I get? I'm running 13-14 psi on pump gas on a daily basis, and on the weekends with 110, I run 20 psi.

Thanks.

 

double post

 

There is a group buy in progress for those of you that are interested. The prices are already very low.

https://www.rx7club.com/showthread.p...1&page=1&pp=15

 

Kansas JoyRide-

PM the shop who is building your engine. I am curious to who is making it run for you.

 

Not to second guess you, and I'm sure WI is solid if Rynberg and others are all up on it, but has anyone actually done any concrete testing to verify the statement above? Ie, anyone looked the AFR w/o WI, and then looked at the AFR w/ it - not having changed a single thing otherwise?

 

you won't have to check A:F...

a dummy system as coolingmist and most DIY's, you can't tune for water, because the solenoid is not high enough speed to keep up with a fuel injector. That's the only way to have the same water:fuel...at any rpm any load.

To tune for water you have to have a map (some have 3d map, rpm and boost, but that is money)

Water, in a way kind of increasing octane level...with a proper mixture (tuned) of water air and fuel its harder to ignite. So, you can tune your fuel leaner (which is meaner )...but when water fails, run that lean and BOOM!!

 

the aquamist system 2-D system runs off of the injectors instead of boost. Aquamist also offers a system that can be tuned, however more people end up going with the 2-d or the 1-s system because the map for the water injection ends up being pretty linear (hear say i guess) just wanted to share. I wish i had gotten in on that group buy a while back.... the prices were soooo goood...