uh.. sorry for newbie question but just exactly when and where does the water inject??


is it during the ic? before the turbo? i'm a little confused

 

Why not jut run 104 unleaded race gas to prevent detonation?

Water in the intake CAN'T be good for combustion?

KevinK2, you are my hero when it comes to making a point in as few typed words as possible...

 

When I run my car on race gas at the local road course, I tend to not change any of the settings and rely on the Aquamist mostly as a means of preventing heatsoak after spending all day on high boost.

However, on the street when I'm running pump gas, the Aquamist is both limiting heat related issues (cooling the intake charge) as well as raising the effective octane of pump gas.

-- DavidV

 

I did a group buy on the "Big List" in April 2001. I went with KC Saab in KC, MO. They are into water a lot with the Saabs. The tech support was very good. They know water injection even if they don't know rotaries. Dave at KDR said he received excellent support.

If you tune your car for water and advance the timing and then you turn the water off the car runs like crap and misses. I suppose you could tune without advancing much wo run without water. I just bought a reverse osmosis water purifier for drinking water and my water injection. I don't want to clog the injectors with unpure water. The 3-gallon fuel cell is really great. I go thru a lot of water when I'm pushing it.

Ken

 

Two points.

First, the WRC rally guys aren't running pump gas, yet they all use Aquamist water injection. The reason they use it is as an extra margin of safety and tuning tool for the extreme rigors of driving their cars at insane boost levels.

In any case, how many of us run around on $5 a gallon 114 octane all the time?

As for injecting into the intake, you are injecting into the intercooler piping right before the throttle body. The water mist is so fine that it evaporates immediately. It is this evaporation process that cools the intake charge. I'm seeing temp. drops of 30-40 degrees Celcius after my massive Apexi intercooler.

You may not have been aware of this, but water vapor is a natural product of the combustion process. I know it sounds counter intuitive, but water injection has been around a long time. It's safe and it works.

For more details, please see the thread I posted:
Click Here
I know it’s a lot to read, but it should be fairly interesting to you guys.

-- DavidV

 

[please delete -- double post]

 

KC Saab is an excellent retailer for these systems.

Tuners interested in carrying the Aquamist product line can make inquiries through my agency, Boosted Group.

-- DavidV

 

Does anyone have experience with methanol injection(used instead of water or alcohol)?
I was reading on the Supra forums that some are running methanol with extremely impressive results. They used an AEM EMS to control the injection and used a fuel cell for the methanol.
Just seeing if anyone has tried in on a rotary...

Thanks
Ben

 

Corky Bell states in his book Maximum Boost that water injection is a bamd aid and eludes to his reasoning. The resoning that I think he is eluding to is that most people who run water injection are making up for other short comings in thier turbo system. Be it a turbo running out of its effciancy range, an intercooler not properly sized, ineffeciant cooling system, improper engine tuning, and a ton of other reasons.

In the case of the rotory, it is being considered for some of those very reasons. The engine runs hot, too warm - lacking cooling system. Can run higher boost - running a turbo out of its effciancy range and an impropperly sized intercooler.

So I belive that Corky is on the correct path.
Please keep all this in mind when considering implementing water injection. Put alot of time into why you want water injection and what problems it will solve and if this would be the best way to solve such problems.

I see water injection the same a NOS on a turbo car. A cheap add-on to get quick and most likely dirty results.

Just my $0.02 coming from the VW 1.8T crowd.

SF

 

azndisgrace--you can spray before or after the turbo...but if you spray before the compressor...you must fully atomize the liquid....failure to do so will result in compressor blade damage....water drops are hard when they hit something moving that fast!!!

 

Did you read the thread I linked to at the beginning of this post?

Following Corky’s logic, an intercooler is a band aid for an undersized turbo and a turbo is a band aid for insufficient displacement.

-- DavidV

 

I have now.
First alarm bell went off when I read that you work for AquaMist. Not a big deal but I threw up my defences. I have traveled this road before in the 1.8T community, so I am caucious.

Unfortunatly all I found in your post and in the AquaMists website was that water injection is a system that should be implemented to reduce inlet temps when they are too high from an undersized intercooler, running more boost, or when the stock or existing efi could not compensate.

Basically restating what I had already contributed to this thread.

You yourself do point out a good example though. The fact that you can run out and spend 10k on a turbo system with intercooler and standalone and still not be able to run at the track for a 30min session without overstepping the boudries of the setup. Although, to me, that just sounds like a poorly designed setup that needs more work.
Even the example about your MR2 turbo at the track. Your engine was fine and manifold warm to the touch but you think you damaged the turbo. Again an example of a system that needs work or has some distinct shortcomings.

I must say that I am intreaged simply based upon the level of sophistication of the AquaMist system. I am curious about its implimentation as a failsafe system to prevent engine damage but not as a continuously operating system.

SF

 

Wow, this is more good info than I hoped for

Hey Ken, what did Dave think about the WI kit and the results? Thats where I go for everything.

After reading this I'm thinking that maybe a less expensive IC (blitz, pfs, etc...) and WI combo may work as well/better than a spendier IC (m2) for ~ cost.

DavidK mentioned a 30C+ drop, if thats a reliable number then this combo sounds good.

Not saying that being stingy on the IC is good or anything but for stock turbos, 12ish pounds...eh?

 

Dave has the water kicking in at 7psi and 3k rpms and the volume of water increases as the rpms and boost goes up. I use a lot of water and I'm glad I got the 3-gallon fuel cell for the water. If you saw the pics it's really neat. I have a GReddy SMIC(400CI). The engine compartment is very uncluttered.

I have the Omega gauge and 4 air temp probes. I'll do some runs to get some temp info for you guys.

They are located in the K&N air filter, after the turbo, after the IC and after the WI.

Did a run at 15psi and the peak temp after turbo was 256F. Intake temp was 96. I think the IC dropped it 120F and water another 40F.

http://flathat.woodstream.net/LUV94RX7/

Ken

 

I did a run today using the Omega air temp probes. They are located in the K&N air filter, just before the IC, just after the IC and about a foot after the water injector. That probe is about one foot before the throttle body. The run was from 40-70+(4-7.5+ rpms). Max boost was 15psi.
Outside temp was 22F.
Max in K&N filter was 71F.
Max after turbo was 231F.
Max after IC was 85F.
Max at probe after water injection was 61F.
I don’t know where the Commander air temp probe is, I’m guessing just before the air goes into the engine, as its max was 88F.

These tests will be more helpful in the summer. Today the IC had 22F air going through it at 70mph. When the IC has 90F going through it there is no way it can drop it from 231F to 85F. I think water will be more valuable in summer weather.

As I said before I installed water to prevent detonation. Our beloved rotaries blow up mainly due to detonation and over heating. The benefits of cooler air intake temps, cooler combustion chamber and cleaner combustion chamber are just bonuses.

Ken

 

Be prepared to use a lot of water. My system kicks in at 7psi and 3k rpms. The volume of water increases as the rpms and boost increase. I'm glad I have the 3-gallon fuel cell. I just used 2 gallons of water in 80 miles of spirited driving.

I'd like to see DavidV give us some stats on the decreased EGTs with and without water. If it cools the combustion chamber then the EGT should be reduced.

Ken

 

If I'm not completely misinformed, the main temperature drop gained from water injection takes place within the combustion chamber during compression. That's when the water vaporizes b/c of the heat from the compressing air. Lots of heat energy is absorbed from the a/f mixture to feed the endothermal (or whatever it's called in your language) evaporation process.

What I'm getting at is that it's nearly impossible to correctly measure the most significant temperature drop caused by WI. The lower temp in your intake air after the injection point is not showing the full effect. EGT would probably be a good indicator of the overall achievment though.

 

Wow Ken,
You go thru lots of water. With the Aquamist 1s system set to activate at 10 psi w/ .6mm jet, my windshield washer bottle may not empty until several hundred miles. What size jet are u using? I was thinking of putting the biggest I have in, .7mm.
At idle, if I jump the manifold sensor for the WI and have it come on, it does not seem to affect idle much. Maybe .6mm is way too small of a jet. I dunno.

Steve

 

Something is wrong with my system. DavidV agrees. This was KDR's first attempt at programming the 2s system and apparently he is dumping way too much water in. I have to now look into that apparent mistake.

I'm not too happy about this. Too much water is hurting my power.

Ken

 

This was posted on the MR2 board. A Syclone had decreased EGT of 40C with water on compared to water off. I'm guessing it will be much greater on a 15/22psi boosted turbo rotary. They run very very hot.

Maybe I should get an EGT gauge.

Ken

 

Okay I know, stupid question but:
I have a space fuel pump and spare fuel injectors and a powerFC, could I rig this into a WI system?
Probably not, but worth asking?

 

My friend tried using a fuel pump to pump water through his water/air intercooler. Worked great for a couple hours, then the pump seized. I dont know if it was becasue a fuel pump is not designed to pump water or if it was just a coincidence but I wouldnt try it again.

 

Don't buy anything yet!!

There's a new WI product that goes to market very very shortly here in NZ that's been developed using FD's as a test bed ... the website goes live later today.

Will post the address once it's live ...

 

Hi Guy's

I've been running water injection for about 9 months now. Here's my experiences....

Firstly my setup:
1992 FD ex-japan
ARC intercooler (just a little bit bigger than stock)
G^Sport chipped computer set to run 16psi
manual wategate modification making boost switchable from 13psi to 18psi
3" exhaust (down, mid and catback)
stock fuel injectors
PiNZ vapourjet mapped water injection
lots of other stuff

With waterinjection:
manifold temp is on average 30+ degC cooler
boost is able to be raised to 18psi without detonation on stock injectors (plus re-wired fuel pump to raise voltage)

At one stage I had fuel delivery problems because of the fuel pickup filter on the pump being blocked (nasty problem). I had audable detonation without water injection but with the WI turned on the detonation went away, effectively allowing me to run lean. The WI system I have is mapped to rpm and I can set it to come on at any boost level, plus it have a safety circuit that I use to drop boost if there is a fault.

Check out my site for advantages of WI.... http://www.geocities.com/rx-stephen/mod_water.html

Cheers
Stephen

 

newb question #2


i can understand why this would be very advantageous for the big power people who like to drag their car, but do you think it would be advantageous for a road car? i mean.. is it really worth it? cause it seems like another problem that could possibly go wrong with your car and if the benefit isnt too great should i even bother?