Water Injection
 

Has any one had any experience with water injection on their turbo rotary? I have done as much homework as I can find on the subject and all seems to be pretty good. The drawbacks being that you have to continously replenish the tank doesn't bother me. Let's hear it......:bigthumb:

I also want to know more about this topic....
Bump.........

This is a very touchy subject. Some people swear by it, others think that it is a substitute for adequet tuning / fuel / octane.

Water acts to cool the intake charge and combustion camber. Reducing the engine's tendency to preignite... knock.

I use it on my turbocharged Z3... since it only uses a RRFPR and I have to run 89 octane fuel... it lets me run an extra 4-5 psi without knocking.
I do not use it in my FD since it is fully tuned with a Haltech E6K and I only run 15 psi.

Guys, in case you didn't notice, this is a technical forum. Keep it on topic or don't post at all - period. I deleted the off-topic BS posts.

what the heck. My post about Corky Bell says NO! was on topic
he is very opposed to water injection. Says so in the book im reading right now. I thought that might be something since he is pretty good w/ turbos

There are huge benifits to be gained by running water /mathanol injection. You can run more advance without pinging, you can run more boost on pump gas, so you can overall make more HP. anyone who says that it doesn't work, has got their head cross threaded.


Well done Ryan...........

I would like to see Corky Bell tell that to the F1 engineers during the turbo era:rolleyes:. I'm not bashing on what you're sayin, its just that Corky Bell isn't always right. Water Injection adds a nice buffer zone that can save your motor sometimes.

Well the history on water injection goes back to WWII, the P-52 Mustangs we're supercharged and to get enough cross sectional area for an intercooler, would eventually lead to worse aerodynamics.....hence the inception of water injection. To cool things down. Corky Bell has said some strange things. I too have read his book. If you want better overall cooling go with nitrous, but it's more expensive and doesn't benefit from the tuning. Plus it requires more fuel.......Water injection SHOULD net you better gas mileage.

Isn't this how Jim S. is getting to run his boost in the mid 20s. Water is the recipe for having the motors live with the high boost. Cooling the air/fuel charge with water has been around for a long time and works. We setup racing motors way back in 1979 with water injection and a little alcohol to prevent it from freezing (at least that is what they said).

regards

Rick
1993 RX-7

I know
He has a rather strict tuned or shit theory

Mr Bells theory regarding water injection can be placed in the... "I know shit department"

There are many advantages to running it, I have used it for years on my own cars and on customer cars with alot of benifits.

Do a search on the topic, as it has been talked about before at length. It does work, and it is not a patch up as some idiots would have you believe.

my basic concern is this. the stock intercoolers are really crap, both 2nd and 3rd gens. However, with the benefit of running water injection, you could lower the intake charge temp significantly. The cost for a system from spearco or Aquamist is less than $300 dollars. No way a good intercooler kit would cost nearly as much. that's pretty much the way a lot of the Grand national guys do it. Eventually when you do get a better I/C. You would reap both benefits.

I would like to know how much water is needed to be run....i.e what size jets and how much further would the timing need to be set. I think i pretty much have made up my mind.

Nitrous Express claims that once you have Water Injection set, it's much easier to tune Nitrous.

300cc per minute when above 10psi boost above 5000rpm, below those parameters you need a lesser percentage, anything under 7-8psi below 4000rpm doesn't really need it

yeah, corky isnt godlike but his book definately helps out on alot of stuff although there is a lot of shit that could be changed/slightly modified/taken out or added

HWO:
Did you have to add more fuel when you added the water? I'm running 10 psi at about 4g and would like to have the torque stay a little flatter. Who's system are you using and did you like it? I probably won't run as much water first, but then would increase it slowly. Thanks for all the info......keep it coming.:bigthumb: :bigthumb:

i'm have a very homebuilt system which i chucked together with whatever shit i could find lying around, i am currently not using it, but it does work. basically works on a pressure switch, windscreen washer motor and a irrigation spray nozzle

Water injection
 

I also thought about water injection and its advantages. Has anyone tried injecting water or a water-alcohol mixture using alcohol injectors?

Wow that's serious bussiness, i don't think you would nee that much water...the average aftermarket system uses, much smaller jets .

300cc per minute is what Peter (RICE Racing) reccomended, who plays with water injection on this forum more than him?????

Theory question
 

Would it be better to inject the water after the turbo, so that it is injected into the hot, compressed air, or just before the turbo, so that it might get more atomized by the compressor?

I'm thinking before might be better, because you wouldn't have to worry about good atomization from your nozzle, but I've read on numerous occasions that after is better. Hmm.

I don't think I'd run such a system without safeguards, like a boost cut when the tank runs low, but the idea is... fascinating.

Pre turbo?
 

Would pre turbo injection cause erosion to the compressor blades? I know they are spinning kinda fast. I would think you might have problems puddling too... if you run too much. Other than that I think it might be a good idea.
Don.

I know that injection in front of the turbo is how a lot of racers do it, but then again they don't even run an air filter......i'd say right after the turbo.......but most of the pictures i've seen on 2nd gen that have W/I do it right before the TB.....Same goes for nitrous.

Water injected before the intercooler will condensate. Systems without IC can spray direct in the Turbo inlet, with IC it won't work well.

Most people i know running water injection spray it pre turbo and then it flows thru the intercooler, dont know of any of them having problems with condensation.

Let the intercooler do its job then have the wter injection after the intercooler. Seems this would offer a cooler charge prior to combustion.

On the other hand, injecting the water before the I/C means the air going into the I/C is cooler, allowing a smaller I/C core or getting better performance from a same-size core. (I don't think water will condense at such high temps)

Also, IIRC while the water injection does help cool the charge down, its main advantage is that it acts like a buffer in the combustion chamber, slowing down flame propagation similar to how higher octane does it. I recall water injection setups for N/A cars with high compression.... (boingers)

I think that on a 2nd Gen it would be best to place it after the I/C. that's a great place if you want to make sure that it atomizes well. Also by installing it after, and you got a different I/C set up later in life then you could retain the stock injection point. That and the fact that the few 2nd Gens that i haven seen have it installed there. So in a way it's a proven installation point.

I read that you shouldn't inject the water/alcohol mixture before the turbo because this will eventually erode the blades. They (Grand National boys) recommend injecting right before the throttle body. Check out this site http://home.att.net/~stevemon/AlcoholInjMod.html

you just need to make sure you use pure water and methanol that has all been filtered

Inject before the T-body?
 

What about installing these injectors into a Greddy elbow, that is preholed for injectors?? Is this a good area to have them??

I posted about running 25psi with water and methanol, Itried it and it does work , the car worked totally different.I am using the AQUAMIST kit , which is the best on the market ,if you want to inject before the turbo then what ever system your'e using should have good atomisation or it would damage the compressor blades.
A word of caution though , if you are tuned for H2O , you had better not run out of it under boost!!!!.

I'm currently in the middle of my single turbo conversion and I'm absolutely adding a water/methanol (75% distilled water/25% methanol) injection system. I used it when I owned a grand national and wanted to push 30+ psi of boost without going to a surged fuel system to supply enough fuel to prevent KR. And as was mentioned earlier you always put the injectors after the IC before the TB (depending also on MAF/MAP locations). If you run the injectors prior, 1) it doesn't do shit since the compression of air is exothermic (gives off heat) which happens after the compressor so all you would be doing is heating air and now water at the same time reducing the oxygen rich density of the compressed charge since you put water in that space. 2) Spraying after there would already cool the dense charge which is good however the IC de-atomizes the water onto the inside fins killing its efficiency since the air running over the IC is actually cooling the already condensed water sitting inside the IC instead of the air running through it…in other words you’d be insulating the hot air from cool IC air. Guys who run water at the turbo do it to cool the compressor only, plus they have big enough turbos and ICs to where this effect is negligible.
As far as making sure you don’t run out during boost, there are systems which have alarms, monitors and even relays which you can hook up to your wastegate controller to cut power in the event you forget. These top of the line systems run up into the $1000 range but considering that’s the cost of a single low end IC its well worth it when you can go from 20psi to 25psi safely. We all know how sensitive our little rotaries are to knock don’t we?

-ed

Aquamist has a full line of water injection related products including level switches which can be wired to switch off boost controllers , solenoids the w.i. pump (to prevent damage ) . I had all of this but did not complete the install and took her out for a test , she ran like a mother fucker , but unknown to me the SODA bottle which I was using as a temporary tank was empty ( jet=300mi/min - soda bottle=300ml ....duh ) , now I am rebuilding and installing the full sustem - pump, water injector (controlled by the E6K) , nozzle , separate tank and safety systems ( boost controller disable on low water level with dash warning) .
you should check out the AQUANIST site , I had the SPEARCO system also and it pales in copmarison !!!.:D

im going to be running the Aquamist 2C system and have the haltech control it.

if you want one the now is the time to buy as the price goes up on them after aug 15 2002

http://www.teamfc3s.org/forum/showth...&threadid=2741

I have the 2s system. I use a 3 gallon fuel cell. You might want to look into that.

http://www.jegs.com/cgi-bin/ncommerc...06&prmenbr=361

Cost about $130 with install kit.

Ken

I always inject before the IC, infact before the compressor, IT DOES WORK. Aquamist in their instruction book say to inject before the IC to get maximum benifit in a racing application.

but if you inject before the ic doesnt the water condense?
im going to be running water/air ic so Im thinking of connecting my Aquamist 2C right before the TB

I think the operative word is "racing " , once racing there would be a constant high flow of air through the system that would keep any condensed water in motion , preventing it (water ) from " hanging up" within the piping , IC etc.

I got contradicting info from Aquamist.
http://www.aquamist.co.uk/rescr/rescr.html Click on fitting. and look at Q14.
I just pulled this from Aquamist site:

Q 14: Surely if the jet is placed before the intercooler it will have better cooling effects?
A: Not quite true. If the air entering the intercooler is pre-cooled, the cooling efficiency of the intercooler will drop due to the smaller temperature differentials between the ambient air and induction air within the intercooler core. Secondly, there is also a possibility that the hot air from the turbo may cause unnecessary vaporisation of the injected water thus taking up precious volume that was intended for the charge air.

Thank You, moespeed. Just because something works that doesn't mean that it's the best way of doing it. If you talk to any one of the engineers at Aquamist they'll back up what I mentioned earlier. If you still feel there is a better way, pick up "Engineering Heat Transfer and Thermodynamics for Internal Combustion Engines". it's available from SAE publications and was required reading for me back in grad school.

-ed

I figure it was something we should know.
Note:
I just wanted to point out that there may be a difference in what Aquamist is saying in its manual and what's on their site. I have no experience with this product and will not take sides on this knowledgeable debate.
Experience is a bitch.

Well, at the end of the day it comes down to who has "used" the system it all it's specifications.

I have used water injection for around 5 years and have experienced many different points of injection and find the best "performance" result to be pre intercooler.

I have an article from one performance car mag which showed consistent acceleration gains from injecting before the IC as apposed to injecting at the throttle body. You make up your own mind, I know what works as I have done my own experimentation to back up my own theories and it works in my case.

It's a free world, you can choose to inject the water where ever you wish, either way you will supress detonation whichever location you choose.

Do your own analytical tests and you will find which location gives best performance gains, I did, and that is why I inject at the location I do.

This may be taking it one step too far but...

I've heard of propane and NO2 being used together and water and NO2, but what about all three? Ive never heard of propane and water...perhap the upper reaches of 30 and maybe even 40 psi would be possible...

can anyone chime in on the disadvantages of water injection? it'd be interesting to read that shit that was deleted.

here is a pic of the Spearco water injector:

http://www.hardracing.com/CARPARTS/C...s/SPearco1.gif

I posted a thread on the MR2 board about water injection recently. Thought some of you here might find the information useful as well:

Here

-- DavidV :D

It's about tuning really. You could loose power and cause porblems if you over did it.

it would be nice to hook that injection to a knock sensor......... inject when it detects knock and then remember that so it will inject prior to it happenenig

Here's a question. Has anyone who has installed water injection on a rotary and had it done properly and tuned properly ever blew his engine up because of detonation with water running properly??

Ken

Dave @ KDR tuned car with water.