BDC

Howdy folks,

I just recently took a long trip from DFW to McAllen, Tx. Each way was over 560 miles and I did it solo. Needless to say, once the "road trip thrill" wore off, I had a lot of time to myself to think about things. I spent the majority of it ruminating over technical stuff and especially the whole AI thing. I'm not interested in making a "water vs. alcohol" thing as I feel that both fluids are powerful in as much as being helpful to the engine for reliability reasons.

I've said it a zillion times both on these forums and in public: The determining factor in making engine power, hardware aside, is the quality of the fuel used. Period.

Even after my experiment w/ the hot-air setup on my Turbo II, I've still got questions about the modes of action and the real efficacy AI has in our engines. It's my contention that both due to the unique nature of the rotary engine as well as its tendency at creating massive amounts of heat under heavy loads compared to piston engines that alcohol and water injection are very desirable. The longer I continue tuning the cars the more I'm leaning towards the notion that every one of our turbo cars need, at the very least, a basic water injection setup, if not a more complex all alcohol setup. I also believe that, due to the experiments that several of us have done up to this point over the last few years, there's an explosive amount of power with reliability awaiting us once this stuff becomes more technically understood and "standardized". It wouldn't surprise me if the somewhat ambiguous "1 bar on pump gas" deal becomes a thing of the past for us.

So far, we've got these basic setups available to us:

-) Pre-turbo water injection, pumpless (pneumatic)
-) Pre-turbo water injection, pumped (electronic)
-) Post-turbo water injection, aft of the throttle body, pressurized system
-) Post-turbo alcohol injection, pre throttle body
-) Post-turbo alcohol injection, hot-air setup (ala Stylemon and myself)
-) Post-Turbo water/alcohol combination

The properties of both fluids that are important in my opinion:

-) Specific Heat Index
-) Latent Heat of Evapouration
-) Autoignition Temperature (Alcohols)
-) Flash Temperature (Alcohols)

Also, I'm not forgetting that both are proven to combat carbon buildup in an engine. I've personally seen what heavy alcohol injection does to the innards - literally zero carbon on the rotors and little carbon in both intake manifolds all the way to the back of the throttle body (via reversion). Amazing stuff. The lingering thorn in my side I've had about carbon build-up is that not only does it theoretically raise compression ratios artificially but it also can produce hot spots that can act as "glow plugs" and intermittently ignite a compressing charge prior to a timed spark event.

As Howard Coleman's written about in his 3rd-gen section thread, the big one here is the latent heat factor in as much as the cooling BTU's that are delivered when the water or alcohol makes a change of state from fluid to vapour:

"The input of energy required by a change of state from liquid to vapor at constant temperature is called the latent heat of vaporization. When a liquid undergoes a change to vapor state at normal boiling point the temperature of the liquid will not rise beyond the temperature of the boiling point.

The specific latent heat of vaporization is the amount of heat required to convert unit mass of a liquid into the vapor without a change in temperature."

http://www.engineeringtoolbox.com/fl...eat-d_147.html

Some latent heat, autoignition, and flash numbers:

-) Gasoline, 150btu/lb, ~500*F, -45*F
-) Methyl Alcohol, 506btu/lb, ~870*F, 52*F
-) Ethyl Alcohol, 400btu/lb, ~790*F, 57*F
-) Water, ~1000 btu/lb, n/a, n/a

http://www.afdc.energy.gov/afdc/pdfs/fueltable.pdf

The main differences between the two fluids as I see them: even though water has twice the latent heat of methyl alcohol, it's inert, therefore its only real benefit is strictly cooling. It strikes me that given its high latent heat it makes for a stellar combustion chamber coolant (to more importantly work during the compression stroke when pressures and temperatures are going up to help prevent fuel autoignition) as well as efficacious as a turbocharger's compressor coolant when done pre-turbo. Of course, the question of wheel erosion comes into play here with respect to the atomization of water: Can and will it destroy a compressor wheel over time? Water is extremely tough and I can't see a wheel not being chewed up over time if the atomization is extremely fine. But, that's just me. It might be that it's a moot point in terms of the trade-off of being able to extend the operating efficiency of the compressor by drawing heat out of its job of being an air compressor. I read a lengthy article once about how a gentleman, due to pre-turbo water injection, was able to run higher boosts (and prevent overheating) on his diesel truck when it was challenged by heat and high altitude/steep angle towing on the highway from LA to Las Vegas.

The other thing that comes to mind about pre-turbo water injection is this: Even though from a fault tolerance perspective (of not having to run an electric pump that can fail, etc.), if the latent heat factor is the big benefit of water injection, how much of that desirable property is lost with heat being drawn out of the water into the compressor? In other words, how much would one have to inject to be both beneficial to the compressor as well as ultimately the engine's combustion chamber? How much water here is being converted to steam in the compressor and therefore how much is left over on the compressor discharge to be of benefit in the combustion chamber? That's the meaning behind the thread's title, "Modes of Action and Efficacy". While I'm sure some (like rx72c) may disagree here, and that could just simply be due to my ignorance, it seems to me that a water injection setup belongs on an already tuned, 100% gasoline car where a measure of reliability is desired or when a small margin of that gasoline is to be replaced with water (where gasoline is commonly used as the assumed, de facto chamber coolant with air/fuel mixtures richer than 12:1). Perhaps the disagreement I would have with them is because of the massive amounts (upwards of 700cc/min!) folks like rx72c or Rice Racing use in their pre-turbo setups. Perhaps that amount of water is doing two things - moderate charge temp reduction and massive combustion chamber temp cooling. However, I still can't help but believe it's not the best approach (attempting to fight ever increasingly higher chamber temps by injecting more and more water even though the setup is still using the same, base fuel that's only efficacious in a colder and less brutal environment). From a certain perspective, it seems to make more sense instead to do two things: Create the same chamber cooling effects while bringing the base fuel's stability and "heat range" up to better match the hotter and more ferocious chamber environment we're trying to create.

It's kind of like the difference in approach between bringing cold air to the air filter (ala the cold air box) vs. taking the air filter to the cold air. By the way, in my experimentation with taking an air filter outside of the engine bay to the outside showed a drop of 40-45*F in cruising IAT's and no doubt helped with boost IAT's. The type of material used in the ducting, heat wrapping, and all that other jazz did absolutely nothing to increase that difference in temps.

I also am curious what kind of ignition hardware is required for such large amounts of water injection like this and whether or not said requirements reach well past what's normally equipped on these cars.

Even as little as 100cc of water, assuming 100% of it hits the combustion chamber and isn't converted into steam prior, has the cooling BTUs (due to its unparalleled latent heat) equivalent to that of over 650cc/min of gasoline when being used strictly as a chamber coolant! It's 650% as efficient as gasoline as a chamber coolant! That's undeniably incredible. However, other than the possibility of it occurring on a pre-turbo setup, I can't see water being a big help with IAT's especially on an intercooled setup. To make use of its high latent heat, the charge temps would have to be very, very high; high enough past the point where, with a pump fuel setup, knock begins to occur. That's why I think it's better served at the throttle where more of it can reach the chamber in pure form and do its job there.

The argument I draw from the questions above are why I am philosophically-speaking a fan of post-turbo water injection even though I don't dismiss the obvious benefits of pre-turbo injection. In my view, when a powerplant is using an intercooler alongside an air filter setup whose air source is from the ambient atmosphere and not the engine bay, I can see how a post-turbo water injection would be a powerful addition when running an all pump-gas setup. As shown, even a few hundred cc/min of injection, which is pretty easy to pull off post-turbo with a pump setup running high pressure, will do a gigantic amount of chamber cooling, will stave off heat-related knock, and will enable the ability to run somewhat leaner mixtures. It seems like the "cherry on top" of a typical, tuned pump gas setup when we want reliability, even being sprayed in a static amount. Water's not corrosive, cheap, and doesn't require extensive hardware to make safely work.

One side note.

The real reason why the tuning trend over the past many years for pump gas-only street cars being tuned to ridiculously rich air/fuel mixtures of mid-high 10's:1 is because the gasoline is being used as a chamber coolant (a ****-poor one at that) to try and help prevent blowing itself up. Yes, we run fatter what's necessary for power under acceleration (arguably mid-high 12's:1) because it's easy to manipulate an EFI system to inject more fuel under load as a marginal way to stave off engine knock (and even then it doesn't yield a large margin). Let me re-phrase this for those that may not have gotten it: We put more gasoline in because we're trying to keep gasoline from exploding early. I contend the problem is pre-ignition due to auto-ignition (when a fuel ignites on its own due to the hot environment around it) in the compression stroke. I think because of pump gasoline's lower auto-ignition temperature and instability it's making engines blow up at relatively low boost levels. This causes the power stroke to start too early, create wild chamber pressures in the successive strokes, and kaboom the motor. The same thing happens when a nimrod of a "tuner" manually fires the spark plug too early. It also happens when running too hot The other whammy is real detonation: the possibility of being able to cause a second flamefront behind the one initiated by a timed spark event from running too damn rich a mixture (when the mixture is so rich and the chamber being so hot that a second stage of combustion starts on its own). Running excessively richer gasoline mixtures in a denser and denser chamber environment also challenges the ignition system. It's difficult to get much burning past low-mid 10's:1 on a gasoline setup unless the ignition hardware behind it is really powerful.

On to alcohol.

Alcohol, on the other hand, is a fuel that burns and therefore lends itself more closely to the rules and practices of tuning. Depending upon which type of alcohol (ethyl vs. methyl), much more of it in volume is required compared to gasoline to create the same heat energy (Heating value in btu/lbs). For example, if running an all pump gasoline setup with even a 200cc/min replacement of gasoline with methyl alcohol, nearly 400cc/min of that alcohol would have to be used to produce the same heat energy and produce the same air/fuel ratio. Side note: This is also the reason, when fuel manufacturers swapped from MTBE (methyl tertiary butyl ether) as a fuel oxygenate over to ethanol up to 10% volumes, why some folks experienced suddenly running mild to moderately leaner air/fuel mixtures with nothing on the tune or hardware changed.

Other than consumption and alcohol's corrosivity (methyl alcohol in particular) which necessarily calls for strict hardware to be used in said injection system (teflon-cored, stainless steel braided lines w/ brass ends and not cheap nylon or rubber tubing for example), I think it carries multiple benefits over and above water:

-) Incredible charge coolant due to low flash temp; so much so that it's possible to run hot-air with big boost, therefore requiring less intake hardware and a shorter plumbing run
-) Even though only half as good as water, still a terrific chamber coolant
-) "Raises" the base fuel's chamber temperature tolerance due to it being a much more stable burning fuel over gasolines and having a higher "effective" octane rating
-) Much less change of knock due to high auto ignition temperature (almost 400*F above typical pump gasolines and about 200-300 over most leaded race gasolines)
-) Robust alcohol injection systems can inject massive amounts of alcohol, which enable the ability to run heavy ratios of gasoline to alcohol (80/20 and richer), therefore yielding the possibility of running a less hardware intensive fuel system (not needing to max out large injectors or run humongous fuel pumps)

One more advantage that alcohol has is this: it contains less carbon atoms than gasolines. Therefore, richer mixtures (in alcohol volume) can be run without flooding the motor and fouling out plugs. When one runs a gasoline to alcohol ratio like I've experimented with (70/30), where alcohol injection is at and over the 1500cc/min range, it's possible to run air/fuel mixtures in the 9's and experience none of the problems associated with that same mixture on an all gasoline setup. The benefit is this: the extra alcohol is used as a chamber coolant. We can throw even more cooling btu's in the mix while still producing power. It's no surprise folks like Howard Coleman run low 20lbs of boost with mixtures in the 10's:1 on gasoline/alcohol ratios around 80/20 to 75/25 and have zero knock. I've done the same thing at higher boost levels, without an intercooler, breaking all of the accepted "tuning rules", over and over and over again.

600cc/min of methyl alcohol injection is roughly equivalent to 300cc/min of water injection. It's got the cooling capacity of nearly 2000cc/min of gasoline. If you do the math, that's a lot of fuel injector.

Take a 680/1680 injector, large-shaft T4 turbo, street port setup. It can run about 25psi of boost on leaded race gasoline, aiming for a conservative 11.0:1 air/fuel mixture, at duty cycles around 90-95%. Total injector output is around 4200/4300cc/min. Removing one air/fuel mixture point (going from 11:1 to 12:1) would remove about 400cc/min of injection. Replace that 400cc/min with 800cc/min of alcohol to aim back to that 11:1 air/fuel mixture. Not only does that 9% replacement reduce the overall carbon being tossed into the motor (allowing it to realistically run a richer mixture without challenging the spark plugs), it's also increasing the cooling btu's of that 400cc/min (38lbs/hr at 5700btu's/hr) to 38500btu's/hr! That replacement of 400cc of gas with 800cc of methanol will cool 6.76 times better. It'll also make for a more stable fuel that burns colder as well as stretch out the maximum power output of the fuel system.

My experience over the last four years of messing with alcohol injection has shown me that alcohol is where its at. Again, I'm not trying to make another soon-to-be-closed thread that's devolved into Internet heroes fighting about "water vs. alcohol"; this is simply a subjective opinion based on observation. While I'm aware that there's a few folks that go for big boost with huge amounts of water injection (all of them pre-turbo, I think), I still like the idea of attacking the heat-related problems in this engine by pointing the guns at the base fuel and making that base fuel more stable and predictable (with alcohol) instead of trying to drown it in massive amounts of water. That's just me and so far that experience, plus the other beneficial effects of alcohol like being able to run a hot-air setup, have pointed me in that direction. Again, not trying to knock water; I like it for certain setups. I just see alcohol injection taking us further.

Those of us that've used alcohol extensively all conclude the same thing: The more alcohol, the better. The rotary loves it.

What's the overall goal here? We're cramming more and more air into the engine in an attempt to produce more power. What makes power? Density of charge. What comes with increase charge density via forced induction? Temperature. When pressure rises, temperature goes right along with it. We generate more pressure with our desire to run more boost and make more power. The high temperature is the negative byproduct of our efforts to run more boost. The rub is trying to keep this temperature within certain limits (depending primarily on the base fuel, spark plug temp heat range, and other hardware). I think the idea that some folks seems to draw glory from in running high boost on strictly pump gas is foolish as it reminds me of the idiot that stands at the end of the cliff, inching his tippy-toes ever closer to the edge, challenging himself on when he'll eventually fall off. This is where the magnificence of AI comes in and I think for the reliability factor on our engines we all ought to delve into it seriously; so seriously that we all consider it necessary in having a tuned street setup.

Barry? rx72c? Howard? Anybody else? Any thoughts?

B

BDC

Of course, this all sounds great, but I still have questions:

-) Even though we can calculate roughly the latent heat values and all that jazz, just how much is actually needed?
-) What's the best delivery method? Pre-turbo (definitely not for alcohol I'd say) or post-turbo?
-) Why is it, on my hot-air setup, the first version of it failed and knocked the motor like a kid feverishly shaking a can of marbles when I had the alcohol injection nozzles downstream at the throttle? Why did it magically work when I moved them way up-stream and staggered them apart (and therefore saw the dramatic drop in IAT's)? What's the difference between flashing in the intake pipe vs. the manifolds?

And on and on it goes...

waltersaegir

Brian, did you ever post the dyno results from your alcohol setup?

I know that you had some exciting seat-of-the-pants improvements, but just curious.

BDC

Unfortunately I never did. I was idiotic in continuing to do highway tuning and never putting it on the dyno where it belonged. I should've done that seeing as how it's an experimental setup. It deserved a few hours of time on it. Once I get it all back together, it'll go there quickly.

B

ronbros3

quick question,, why is it apart???

BDC

I cracked the upper dowel land on the back housing a while back. I was bouncing off the spark cut rev limiter in 2nd gear showing off to my wife, blowing flames out the back at night. Did it several times... then started smell oil.

B

ronbros3

i sure would like to come up with a magic bullet, so rotarys can take abuse , and make lots of power that is available with there VE capability.

i got some ideas but no money, to test!!

pmrobert

What ideas do you have?

BDC

I still think alcohol is it; more so methyl alcohol. It's got too many benefits over and above gasoline to be ignored. Sure, it's corrosive, a pain in the butt to get set up properly, but so what

B

rotarygod

iTrader: (1)

People run excessively rich gasoline afr's to fend off detonation but it isn't due to heat rejection abilities of gasoline. Gasoline is terrible at it. A super rich mixture may make about a 10 degree or so difference in air temps. That's nothing. A richer mixture is harder to ignite and slower to burn. A leaner mixture is easier to ignite and burns faster. This is a large world of "if's" and "but's" though as then pressure comes into play. A mixture burns faster in denser air and slower in thinner. Put these attribues together and you get some interesting things that start to become clear when studying fuel and timing maps.

When people run absolutely ridiculous mixtures down in the 10:1 range, they aren't helping to cool jack ****. They are slowing the flame travel down. You'll find that as a result you can typically increase timing a bit as a result of running overly rich as opposed to leaner. It's only because of flame speed from being too rich. Many people running these afr's somehow think it is helping control their combustion chamber temps but they are wrong. It really isn't. All they are doing is literally wasting lots of gasoline in order to get their flame travel to a slower speed which is what will control preignition or detonation. Of course still getting too hot will still cause detonation. A slower flame travel is only prolonging the effects of it. You can keep adding fuel until you get so rich that it won't fire anymore. That's about as slow as flame travel can get! Unfortuantely with slower flame speeds, the timing isn't optimal to take advantage of burning fuel and it is literally wasted out the tailpipe.

A better method is to run the optimal afr's such as high 13's and then control intake temps through water which will absorb that heat but not contribute to afr's. Again this always has exceptions as too much water will extinguish everything. You'd be surprised just how much water an engine can injest and still run though! By running the proper afr's, and only controlling temperatures, you can now use all of it fully by controlling timing to do so rather than to use it to waste fuel. You'll use less fuel and make the same power, if not more than running no WI and running way overly rich mixtures. This is even a viable method to use on naturally aspirated cars running in hot climates. It won't have the huge power benefits that a turbo engine can have though but it can be useful.

Obviously I'm not getting into alcohol injection but am rather only speaking in terms of why people run overly rich afr's even though most have no accurate idea why and what a better way to control it is than simple running rich.

BTW: I use the steam clean method on my engine every other oil change. I hold the engine at 2000 rpms. It sucks down a full 2 gallons in less than 5 minutes. Calculate the gasoline to water ratio in my engine during that time! There is a whole lot of energy in gasoline and we waste most of it.

Wo:Deep

Hi Brian.

Great writeup.
I´ve read your post carefully and cannot say anything against it.

It really shows potential of whatever kind of AI -System with water and or alc.

I just want to add some more thoughts you heaven´t talked about.

To start with, I want to quote something from your post.

This point is correct in your case.

In my case it isn´t the reality.
Let me describe it.
I´m driving a stock port, stock twins setup. the rest is fully tuned. Lets say it is maxed out.
I´m driving it on the street and the laws here in germany are freaking strict.

So I have to take a look about emissions, exhaust and intake tone and volume, etc.
anything else then a mild streetport cannot be realized while staying street legal.

Next point is that we have to make a emission test when changing to single turbo.
One test costs around 2000$ and IMO with a really powerful singleturbo setup it isn´t possible to pass the test (at least before heaving payed the 5th try :-S)

So Staying with the twin turbo setup is all we can do + when we want to come close to the 400hp, we have to max out the twins.

Now lets move on ontopic.

My Setup will be:
2x80cc/min + 1x M2 (180cc/min) preturbo nozzels.
>> To max out the turbos you HAVE TO GO PRETURBO.
Our crappy small twins, have a efficiancy around 50-60% @ 1bar and lets say something around 40lb/min air
Yes you are right. there is no map on the earth. But those are the more or less known values for our turbos.
So with preturbo you can go to lets say 70%compressor efficiancy in this working point , or in other words 44 instead of 40lb/min of air @ the same boost.


As you can see there are more reasons to go preturbo then pushing a shitload of water in there to get some of the water to the combustion chamber to cool it down and then prevent knock.




On my setup, as I said, I´ll drive with my 3 preturbo nozzles and ONE M5 or M7 nozzle pre throttle in my PANSPEED Elbow.


I think you´ve got the Idea.

Preturbo, to get the best out of the twins.
Prethrottle (additionally) to prevent the knock.


As you said. The question of water vs. alc is not the case.

It is your setup,external circumstances and goals which pretend to go with a certain setup.

The beautiful thing of such threads is.

You get the theory (And your post had not to much but the interesting and important facts).
You get the ideas what and how to do it right.

Thanks for the thread!

+AMEN to "rotarygod"


Additional Information about my setup: (before you start asking!)

1. preturbo.
Preturbo setup is installed and running.
Unfortunately the wastegate of my first turbo stopped working as I wanted to make the first tests. I only had two or three runs with the Preturbo setup and working first turbo. (only 0.6bar and crappy boost buildup now )
It is really a step foreward.
But unfortunately I had not enough time to really make some more tests. But they will come.

When running with my second turbo at 1bar. the IAT will be slightly over the outside air temperature. thats great.

2. prethrottle:
I´m waiting for my Piping to fit in the PANSPEED elbow. so the prethrottle injection isn´t activated at the moment.


About the Water / Alcohol question (in my case):

As a road car, I don´t really want to carry pure alcohol around the streets

At the moment with only preturbo I´m running pure water.
Tuning will start when I have installed the prethrottle nozzle.

I´m running 10.5-11 AFR at full boost at the moment.
When running with the water I´ll go to around 12AFR.

(the 13AFR rotarygod said now gives me something to think about?!? Isn´t the perfect AFR 12.5????)


Then the knock values will show how much I can go further in terms of advanced timing.

Maybe you can tell something about that approach, how I´ll do it. I think I don't make any mistakes doing it that way.

How much alcohol I´m using in the end will not be too interesting.

goal is:

best power to reliability.

so preturbo for power!
prethrottle for reliability!

water / alcohol ratio for best compromise.
+ alcohol limits will be given by security and handling reasons. (maybe 20% methanol)


What do you guys think?!?!?


kind regards

Marc

BDC

Great post. I didn't consider that about your circumstances on the stock twins. It gives me some ideas. Thanks!

B

Dudemaaanownsanrx7

iTrader: (23)

Just saw this thread. I'm on my cell so this is going to be briefish. In my experience with preturbo water injection, water made no major difference to the iat's. But even after an extra 8 psi of boost (15 to 23psi) the temps stayed the same so it must be doing something. They also used to climb during a 1st -4th gear pull, but with the water that's not the case.

My knock stays in the low 20's (no knock) and I inject about 600cc at 23 psi. So whatever water turns to steam at the turbo is of little concern. I'm also curious what happens to the "steam" in the intercooler.
Maybe it turns back to water? Maybe it helps the intercooler get rid of heat. I have no idea, but it works.

It was mentioned in another thread that steam will also turn to super steam and pull even more heat at this point. So it's possible, even if all the water was steam there is still a significant amount of cooling inside the combustion area.

Lastly my ignition is really not great. Twinpower, stock coils, iridium plugs. (About $500 total) I have no trouble burning my mixture at those boost levels. Going through the compressor fully atomizes the water, which will make it easier for it to burn and do it's job of cooling. My system is perfect for my setup and that's the key when picking anything for your car. That's all for now.

j9fd3s

iTrader: (3)

i don't know about the rest of it, but to the first question

http://www.not2fast.com/turbo/glossary/turbo_calc.shtml bore and stroke are 94mm, it only uses the displacement in the calcs, so it doesn't really matter, if its "right"

BSFC, on a turbo is mid .7's, depending on AFR, stock t2 might be closer to .8. non turbo is high .6's, PP low .5's.

i've noticed you can set it up, with the intercooler, remember the air temp #'s and hp, remove the ic and replace with AI, until it duplicates the same numbers as with the IC.

in other words, the AI and the IC actually have exactly the same function.

its dependent on a couple of numbers most of us would need to take an educated guess at, (ve, bsfc) but it should be in the ballpark

the second question; i agree. it seems like alky can't go preturbo. while water can do either, and with water preturbo you get the benefit of it helping the turbo work better too.

personally if i had to do an AI system, i'd be running a passive preturbo water one, its the simplest one, plus i'm not really a fan of having another flammable liquid in the car.

mike

Dudemaaanownsanrx7

iTrader: (23)

I would say a 50/50 mixture would "probably" be safe preturbo. Might pick up some power with lower IAT's this way too. I personally am not concerned with making more power. My clutch barely holds this amount, and my current tires don't hold it at all. At a certain point extra power is just wasted in a cloud of smoke. And a few ponies in a street car isn't going to have a major impact on a 5-600 hp car.

If you're concerned with every drop of power then there's other fuels other then gasoline + aux injection that are better suited to wringing every last drop of power.

My car has a budget, both in the build and in use. What fun is a monster of a car if you can't afford the fuel? Water is free, and if there was a feasible way to make it run on 100% water I would be first to jump on board.

Wo:Deep

I don´t no much about th steam >> Super steam - theory.
I just think the good thing about steam in the combustion chamber is always, that you´ll have the water in it´s HO- / H2O+ form as the needed chemical reaction partner to get the full CO to CO2 reaction.

So even with completely "steamed" water entering your combustion chamber, it can still do something good to your combustion!

regards
Marc


btw.

It´s right that alot of people can tell alot (also of ****) in the WWW while never ever heaving even seen a rotary engine.

But you can say what you want.

I´ve seen that I can run the same (or even lower) knock values and even lower EGTs since I heave installed my AI-setup. Even though I have changed the following:

- leaner mixture @ full boost (12AFR instead of 10.5AFR)
- 3°-5° advanced timing @ full boost

I think those numbers speak for themselves

Dudemaaanownsanrx7

iTrader: (23)

"The proof of the pudding is in the eating", I don't know exactly what all is happening in a preturbo setup, but the results prove it works, and that's what really matters.

rx7 SE

iTrader: (5)

hmm, I may just do my senior design on this topic...

I hear about lowering AIT's and all the different methods, but, I don't actually here what the 'ideal' or 'safe' AIT numbers are? What numbers are nominal when you are trying different methods for lowering them?

BDC

On pump gas strictly, I don't like seeing IAT's in the mid 100's *F. My "yellow" zone is in the high 120's to 130's and my "red" zone starts in the 140's. Motor seems to start knocking around low 150's when in boost. At least, that's been my experience.

Race gas is a whole different story.


I agree with this wholeheartedly but there's a left-brained side of me that still wants to know exactly why. I guess I'm too much of a numbers geek.

B

Dudemaaanownsanrx7

iTrader: (23)

Ideal ait's is low as possible due to increased air density and more power.

I don't like to see anything over 50* c and prefer under 44*c for safety.