Tuning Up on Water Injection with E10.
 

I am currently running an A/F of 10.8 at 16PSI with 550cc's of water on the stock twins.

I tuned the car like it was running straight gas NOT 90% gas 10% Ethanol.

Is this safe or should I go even richer on the A/F ratio because of the fact that it contains 10% Ethanol?

My knock in the high boost high RPM ranges are under 40 and my mods are in my sig.

Thanks

knock is key and you are fine at 40. the problem is that knock readings are generally after the run and if you get alot of knock all of a sudden it could damage your apex seals before you become aware.

what octane is the gasoline?

additionally, the stock turbos start to cavitate above 14 psi so running 16 you are superheating the air. you might make more hp at 15 or 14 psi as the compressors might not be heating the air as much. (it is all about how many oxygen molecules per volume... hotter air has less)

i would be cautious w AFRs because you are running alot of boost w the stock turbos. if you had a single i would tune for mid 11s.

good luck,

hc

You should be safe there especially with that much water. Water will raise the knock threshold of the fuel you're using. If you're concerned about the water system running out of water or failing then you might be on the risky side but would prob still be ok.

The gasoline is 92 octane.

I am aware that the stock turbos become inefficent above 15psi. This is just a drag tune. It's just so I am sure that I will run my time .

So you think that I should run even richer than 10.8? If I go to around 10.5 or less, I start getting breakup because it cant ignite all that water and fuel.

Also, my IGL at that boost is 13 degrees. Also, my air intake temps are around 40-45c. The water usually drops it 15 or so degrees.

I am not worried about running out of water or my system failing as I have an AEM system and it is pretty advanced. I also fill up water each time I use the car.

I've heard people say before that water raises the the knock threshold of gas. But, last night I read Brian Cains article that is stickied on this forum, in that article, he says water doesnt not raise the knock threshold of gas. Gas will still auto-ignite at 490F no matter what.

With that said, I understand that water cannot bring up a fuels auto-ignition temp, but in theory, wouldnt it cool the combustion chamber thus allowing more leeway?

I'm still getting in trouble for that.

Yes, that's exactly right and it's what I should've said in that article I wrote a few years back. By what degree it works, however, I don't know. I won't knock water injection like I have in the past when I first started goofing with this stuff. I still don't think it's anywhere near as good as alcohol when it comes to the whole Aux Injection thing, but I can see water having its benefits for high load. It certainly should be yielding substantial durability and reliability to the engine but I just don't know by what degree and with how much water would be necessary.

B

Good to know, so, with that said. What type of A/F can I tune up to? My current 10.8 with 550cc's of water is pretty rich don't you think?

Also, my first question still hasnt been answered. I tuned for gas, which is 14.7 stoich. E10 is 14.3 stoich, so, wouldnt it be a little leaner? I am sure it won't be by much, but I just want to make sure.

IMO, thats just fine AFR wise.

As for the ethanol content of pump gas....don't even factor it in. Ethanol content varies, and the itsy bitsy amount won't make or break things.

10.8:1 is plenty safe, and bordering on being too rich. As you stated, you likely won't be able to go much richer if you're not running an arc welding ignition system.

I've had good success with straight water, but the gains have been hard to nail down so far because I've had a myriad of other problems that break my engines :lol:

Lol yeah I think this is the second thread in 2 days where Brian's comments from awhile back were brought up and questioned.

I think with the amount of water you're pushing that running leaner should be fine. Especially if you keep air temperatures within check. This is one of the benefits of running AI. You can run more boost, raise timing, and use less fuel. Of course the further you tune up the more you take away from the safety net of AI. There's one guy on here that's has been running the stock twins to over 20 psi for a couple years, he doesn't use water even though he has a kit. I would call his results the exception rather then the rule, and personally wouldn't do this.

My suggestion is to keep timing on the conservative side, and pull some fuel out to 11 flat. Keep an eye on knock and air temps. This should still be safe while being conservative with the water on. You could probably even go leaner then that but one issue with the stock twins is they are so restrictive that they hold a lot of heat and the leaner you go and the more boost you run the hotter everything will get. Which puts more stress on the turbo's the manifold, and the internal parts of the engine. The main thing to keeping a rotary healthy is keeping the heat down. Oil, water, intake temps, combustion temps the cooler you can keep them the happier the engine will be. (within reason, don't just dog on a stone cold engine)

As far as my view point between alcohol and water, I'm really not biased towards one or the other. Water pulls more heat out of the combustion chamber per volume, alcohol pulls more out of the intake charge, alcohol burns easier so requires less out of the ignition system, water is free. Both get the job done, both make more power reliably.

Oh yeah and as far as tuning AFR because of alcohol content, it doesn't work that way. You use the exact same numbers you're used to with straight pump fuel. The wideband reads oxygen content not fuel content. It doesn't care what fuel you use. Even If you run straight alcohol, while it has a different stoich value, if you tune with the wideband just like it was normal gasoline, the mixture of alcohol will be correct.

So take an engine and feed it straight alcohol. You tune it to 14.7:1 AFR (stoich for gasoline), well the actual fuel being put into the engine will be more then that. It will be whatever stoich is for alcohol. (6:1????) So don't bother confusing yourself with whatever stoich values different fuels have, it will always be correct if you use the same values your used to with gasoline. Widebands read in lambda and convert it for us so we can see numbers we are familiar with. 1 lambda is stoich for whatever fuel you are using. 1 lamda = 14.7 on the wideband display unless the wideband has been screwed with to display a different stoich value for some peanut that's trying to complicate things.

I'll be tuning to 11 A/F's then. Thanks for the good info.

Some of the responses above are a joke and show some of the inexperience in this place.


WATER INJECTION is one of the BEST for killing out knock.

I am running 30PSI OF BOOST from a gt42r on a 13b on normal pump fuel. No Knock what so ever.
My engine is very reliable and makes healthy power.I will say here. I run 0 alcohol, 100% water.


The setup you detailed in your first post is excellent. You will have no problems. Continue tuning the way you are you will be fine. The AFRS you have chosen will net a healthy power output as long as your ignition is up to the task.

How much water are you running with your setup?

He runs a lot of water. I know one engine he refered to running something like 1100 cc pre turbo and an additional amount after the turbo. I think this may have been a different car though? I'm only running 500 cc preturbo at 20 psi on a t70. I've wondered if more water would be better. I've already increased it from 380cc.

wow isnt a m5 alot preturbo? im considering doing a m2 preturbo and m10 post. running 30% alky/70% water

As long as the water is well atomized you can run quite a bit of water through the turbo without damage. I use an air atomizing nozzle for my setup. It uses boost pressure to pressurize a tank and force the water out at low pressures.

I think mine flows similar to an m7.

im using a devils own nozzle

On my car its a 1150cc nozzle from coolingmist running at a 150psi and turbo is fine. No damage what so ever.

the above amount of water i am using is too much. Should be 7-900cc. (cant tell you exactly, still expirementing). I know for sure the current amount of water for 30psi is too much. More appropriate for 40psi.

What HP are you making at 30psi with the water?

Also, not sure if you are into drag racing but have you ever timed the car?

How does the car respond on full throttle between shifts?

Anthony

Too much water why? Does it misfire? Lose power?

I thought my 550cc were a bit overkill for my setup. :P

I'll be honest I was running 10psi~300hp at the track and just turned my water inj. on to see how much it would cool everything off with a 500cc nozzle and it was to much. It started misfiring and I could tell a noticable difference in power.

I installed it for higher boost levels, 16-18psi, I just don't run more than 10-12psi on the road course and wanted to see what it would do.

550c for 10psi of boost is too much. But if you had a good ignition it wouldnt break up.


With my car. I know its too much water because i have to run lean mixtures to get it to make hp. Were as other Water injected cars that have the right amount of water, can run mixtures in the high to mid 10s and make more power then mine.

Car has made 543rwhp which is low. And it was much lower trying to run the mixtures i wanted to. I will note that my car is NOT PORTED. IT HAS FACTORY PORTS.

I will have some more data soon when i get some more dyno time(been busy) with the smaller jet. And i am very confident 600+rwhp will be a walk in the park.

If that's directed at me then I'm happy to accept it. I'll admit I've got little experience with WI so I don't have much of a pool to draw on. I could be mistaken about some of the conclusions I've come to about it. And while I'm not meaning to turn this thread into an "alcohol is better than water" fight (again), I can say with the utmost confidence that alcohol has been very good to me. Perhaps my cynicism with water is unfounded; I'd love to be proven wrong about it as all it would do is show yet another great AI avenue to pursue.

B

I think alcohol is great. Its just not practical for everybody, certainly not for me.
Water is cheap:)

The comment was not mean to be an attack or anything like that, i just get frustrated alittle. Water is great if used correctly. Alcohol is the same. Used in the wrong amounts will give you different effects.

lots of good info here. thanks all for sharing

Thanks for sharing some of your experiences on WI, I've been really interested in building an FD with heavy boost on PUMP for over a year now and would like to go with straight water and no meth for many reasons. Please PM me and keep me informed asto your progress when you get around to finishing your car bro... thanks :icon_tup:


~ Kayvon



PS; Can you tell me a little more about your set-up? Year/make, turbo, boost levels on pump, ECU, ign, inj's, etc, etc.. thanks

im running post turbo now with hopefully a pre turbo soon. running pure water scares me a bit. at least i know the alcohol is like a fuel.

have u tried mixing them? or have only stuck to water?

100% water.
No need to be scared.

It works like a champ.

My setup is nothing special

Engine:
Factory cosmo RE engine
8 dowells Per face(done by me)
NO PORTING
Rotor And Gear bearings have been modified
S6 Oil pressure regulator
Rotors them selves are FACTORY untouched.
Running 3mm Rotary Aviation Super Seal
Solid 3mm Mazda Corner Seals

Turbo:
Raceonly GT4202 with .91 T6 Rear(this is one of our first inhouse Ball Bearing Manufactured Turbos and i have been testing it for a while on my car).(we made the core, inlet and wheel and exhaust wheel, moulds for the front cover and rear housing are not complete yet so using garret parts. Everything else we made.

Inlet:
Factory Cosmo Inlets Untouched and standard in every way possible:)

Fuel:

2X Raceonly 044 Fuel pumps
1X Raceonly Fuel reg
6X1700cc Bosch Indys

Ignition

4X R7420 11 heat range spark plugs(thanks rice racing).
2 X Crane hi-6 boxes and lx92 coils
2X Mazda trailing coils
1 Microtech X4 box

ECU
Microtech Lt10s 4 bar map sensor, 12000rpm map etc

Exhaust

Manifold is NOT tuned length, as short as physically possible with having the steering box in the most annoying place, have the wastegate venting from the collector near the turbo flange, and holds a solid flat line 30psi.
Raceonly 60mm Wastegate.
3.5inch Mild Steel Exhaust with hand made resonator and muffler


Water injection
Coolingmist 150psi pump(250psi pump on its way soon)
1150cc jet Pre Turbo
Triggered by Eboost auxillary
Very primitive system runs flat out all the time.
Comes on at 8psi.

Car makes 543rwhp as of its last dyno session, i dont have any dyno sheets for the last bit of tuning i did, last dyno sheet i printed out was a long time ago 511rwhp.
Running 12:1 Afrs in some areas, tune was not finished, deeps into the low 11s over 7500rpm.
I dont recommend many people run the above afrs with 30psi, i had no choice just too much water. But jet is getting changed.


Here are some pictures

http://www.raceonly.com.au/images/wi1.JPG
http://www.raceonly.com.au/images/wi2.JPG
http://www.raceonly.com.au/images/wi3.JPG
I hope that goes into enough detail.

wow nice setup. whats cc compared to gph?

19gph

HOLY COW PRETURBO?! @_@

im running 10gph post, at one time was running dual 10s with 70%water on factoy plugs and coils and didnt really noticeable a stumble. comes on at 5 psi, full blast at 10 psi. since then i have removed one.

Update - I leaned out all my boost areas by .2. So, I am now running 550cc water at 16psi with 11.0 A/Fs. The AEM kit I have is progressive, so it comes on at 0PSI and increases to 100% at 16psi. There is no dyno on my island so I cant prove this with numbers, but I've made multiple 3rd and 4th gear pulls and can definitely fell a power diffrence. I can tell that I am getting a complete burn. Power comes on smooth and strong. Knock readings are 25ish in the high boost and RPM areas. Intake air temps droping around 15c with the water on full blast.

For anyone with my mods or similar, I would recomend you start with a 300cc injector, tune with normal pump gas A/F's, then move up to a 550cc and fine tune like I did. Worked like a charm.

That's why I use straight water. Its more practical for me. Meth is hard to get and costs $6 a gallon where I live and, I have a VERY heavy foot. :D

Happy their are more tight arses like me around lol

doesnt straight water leave deposits behind?

Nope.

That looks neat, rx72c!

My concern with doing the pre-turbo injection has been the notion of corrosion. Have you done this setup for a very long time, on this same turbo, to see any of that kind of negative effect or do you know of anyone who's run into that?

B

I haven't been running pre turbo water for long but show zero turbo erosion over the last several months. I can see where the water has been flowing at the inlet it kinda has a swirl mark but its just dried water spots no erosion.

I have a customer car that has been running it on his 35r for close to a year now.

0 DAMAGE TO THE WHEEL.

He has been running the same amount of water as me up until recently. Did some changes to the car, smaller jet, shsv valve and haltech platinum 1000 so will be on dyno soon to try and break the 500rwhp with 35r.

Hmmm. Not to be argumentative then, but why am I reading and hearing things about compressor erosion then?

B

Because people talk shit.

They think it will do it, so you get e-know it alls that say, oh shit you cant do it cause youll get erosion.

then you find all the people that try it, you dont get a single one with a problem.

their is a shot of my compressor wheel in the above photo.
Show me where the pitting or corrosion is.

Older systems that didn't atomize the water properly had compressor erosion. I suppose any system that isn't designed with this in mind could have issues. Better nozzle designs and higher pressures with pump type systems helps keep the water atomized. My system for instance comes out in a fine mist even though it's a low pressure system due to the nozzle design. I researched this extensively before putting together my kit. Another thing i read about a factory preturbo system was even when turbo's had erosion it didn't effect the performance of the turbo, this was on some car built in the late 80's. Don't recall the make and model. But really with a proper system design compressor wheel damage isn't an issue.

That rhetorically counts for a huge percentage of stuff found on forums in the first place. It's why I try hard to take a stance on only listening to those that actually do something or try it myself. I'd rather fail at something and know of a wrong way to do something than not.

I don't see any pitting or corrosion on it but in all fairness the picture in and of itself doesn't tell the whole story. It's why I'm asking because I'm curious about long-term use and whether or not this corrosion problem is really a problem or something that some folks, who've not actually tried this stuff, came up with out of thin air.

B

I believe that. Sounds good. Maybe it'll motivate me to add a small nozzle pre-turbo during this next hot-air iteration of mine and see if it produces any benefits.

B

As far as i have seen.
No problems what so ever.

Now with 250psi pumps and even better jets the likely hood of pitting on comp wheels is decreasing.

just ordered my 2gph nozzle :) now i need a mini intake to screw nozzle on.