Isn't heat what pushes the rotor? Can more power be made at 15 psi from AI when pump gas will do?

Is race gas kinda like AI in the same idea that it has heavy leads to soak up the heat too?

I can see good oil cooler and radiator as being benificial to prevent pre-ignition.

It is begining to sound like AI is a safer alternitive to race gas for me (18 +psi )as I just fried my wideband again on it.

Witch is easer to tune/predict water or alk?

 

I believe that more power can be released with WI/AI as compared to pump fuel.
simply wi/AI will allow you to travel further into un enterable teritoty than with regular fuels.

You are creating a similar enviroment to race gas ( there are differances but the fundementals are the same )

Detonation is the spontaneous combustion of some of the air/fuel mixture in a part of the chamber ahead of the propagating flame front, after the spark plug has fired. This happens near tdc and leads to short, very large pressure spikes which "hammer" on everything and can blow head gaskets, pound out rod and main bearings, crack rings and pistons, etc. These spikes can be up to 10 times the normal chamber pressure. In preignition the pressure rise is much more gradual and not the major cause of damage. However, the heat buildup from preignition can lead to detonation in not too many seconds at wot. Preignition is also sometimes called pinging, because that's what it sounds like - kind of like a few marbles rattling in a metal can. Detonation is also called knock, and it sounds like someone is hitting the motor with a hammer.

This is insert is from the innovate froum.

If you can reduce in cylinder temps you window for power and boost will increase.
most find that you can exceed there capabilites before the water does.

the key to this is the pressures/temps at ppp ( point of peak pressure ) if you can reduce this then the tuning world is your oyster. WI or AI will help this.


I have little experiance with race gas but i believe leaded fuels to be detremental to 02 sensor life. Alchs and water have no such affects.

In response to the which is easier question. simply put water is easier. there has to be no doubt. Water has a latent heat evaporation 6 times that of pump fuels. Water will not give you the icy cold temps of methanol but is that really the goal ? or are we after internal cooling.

I am so far neutral untill i can prove one way or the other. so far tey all look pretty close but at high boot (20 psi and up ) i dont know yet. I leave that to people like, RICE RACING, Howard coleman, BDC,BNA ellis to prove.

I 100% agree with howards sentiment. you should add something !

Scott

 

Well I can say this.

I HAVE run @ 0.89 Lambda with water alone, I am not sure if alky runners have tried this???

Looking to drag racing world for advice on tuning is a bit silly @ end of the day IMHO I deal with most of them direct or indirectly on of which holds the outright 13B world record for et and MPH and I would NOT look towards any type of tuning tips from them

These people need to run at far different operational parameters than what your trying to achieve as an ideal for a road going car, its a totaly different animal TOTALY. Those people be it running C16 or Pure Methanol ALL have to run stupidly rich to get any type of durability form any of the apex seal products they choose to run. Typical ranges are from 10.5:1 to 11.5:1, the mean average is towards the lower end of scale (10.8:1)....... again this covers fastest untubbed rotary in world C16 and fastest chassis 13B Turbo Methanol

What we do with water injection is on another level totaly from this philosophy, I have proven you can run reliably at 14.0:1 for economy OR you can actualy set your vehicle up to make MAXIMUM HP (just like Richard was asking) @ 13.0:1 *around about* ratios. Its a BIG PLUS for WI over other types of thermal control in the combustion chamber.

Thermal control is what this is all about at the end of the day, your best gauge of this @ the end of the day is if your apex seals warp, your plug fails OR short term more drastic effect is if you have pre ignition. I know one thing for sure constantly drowning your engine is mainly hydrocarbons does accelerate the wear and tear on it, this same effect does not happen with water, so thats another thing to consider

 

I managed to get back to 0.83L on methanol. I always tune Alchs in lambda its just a more natural figure as apposed to afr which tells you very little/ nothing when tuning blended fuels. My 50:50 tune dipped into 0.85L but not yet at peak tq.

I strongly feal that when tuning alchs you will have to lean out qite a bit more than most find comfortable. At the end of the day this is called progress

I am runing 2 tuning projects
1. 50:50 which is very close to the finished product
2. straight water which is quite a way from finsihed.

When i was out with water i said to my friend who was logging that 13.0:1 felt right. Its one of those things i cant explain.

One thing that has come form the water is the fact i dont have to send the timing map into orbit which brings a certain kind of saftey with it.

Scott

 

If you are running 10.5-11.5 on pure methanol, then you are stupid lean. Stoich for meth runs about 6.5:1.

Rat

 

Not necessesary. If you use a LM-1 its does not measure AFR. It measure L. The afr is a calculation. Im sure many other top brand afr meters work the same.

Scott

 

Yep.

I've been considering looking for a wideband unit that displays Lambda instead of AFR. Know of any other than the TechEdge, Scott?

B

 

Yeah the innovate LM-1. Thats what i run.

Scott

 

Thank you all for the warm welcome posts. I promise to be good.

After reading many posts on this great forum, I would like to contribute something that may help clarify some myth on water and alcohol injection. Please also note that it is only my view. In some areas, I can be completely wrong, I am very willing to take in any comments to correct it so hopefully this thread becomes more meaningful as it progresses.

Water and methanol injection does the same job in different ways, they both perform in-cylinder cooling and knock suppression well. Since water has a higher latent heat value than methanol, you need to inject twice the amount of methanol by mass to extract the same amount of heat during combustion. This is why all pure alcohol injection systems require a bigger jet, you need to inject 2.5 times by volume more than water. This makes little difference in practice except you need to find a bigger container.

Effect on knock suppression is totally different:
Water suppresses knock by quenching peak flame front temperatures hence regulating the frame propagation speed – (too fast burn promotes knock). In-perfect charge distribution produces lean and rich pockets. Lean pockets burn at a higher temperature (oxygen-rich = faster) compared to fuel-rich pockets (excess CO slows down burn speed).

Alcohol suppresses detonation by increasing the knock threshold value of a given fuel grade. Since large amount of alcohol is required to control in-cylinder temperatures, air/fuel ratio will be affected significantly. Some fuel has to be removed to avoid over-rich mixture.

Power producing potentials:
In theory, more power will be produced if more charge is jammed into the combustion chamber, resulting in higher cylinder pressure and temperature. In practice, the associated components such as pistons, turbo turbine, etc has a finite operating temperature constraint. This is normally reflected by the EGT. The general accepted EGT figure is about 900C.

Power is basically a force exerted onto the piston per unit of time. Force (pressure) is generated with heated air in a confined space. If cylinder pressure can continue to increase without temperature rise, we have the ultimate power plant. Water injection and alcohol injection will be a good tool to perform this work, lets examine this in more details how each concept can help achieving this.

POWER TUNING:
(Assuming we have a powerful ignition system, a strong engine and unlimited supply of air and fuel).

For water: the task is relatively simple. First generate as much heat as possible by adding more boost and fuel. Water is then injected to absorb the excess heat until EGT is within a permitted safe level. Overall BMEP (Brake Mean Effective Pressure) is now increased due to the vaporized water. The amount of BMEP increase will depend on the mechanical strength of the engine structure. Water’s ability to push the power capability is almost unlimited.

For methanol: First consider using methanol as a fuel instead of Gasoline. Methanol’s ability to increase power is confined to the knock threshold, and available heat to increase the BMEP of an engine. Methanol has only about half of the energy content of gasoline, so twice as much methanol has to be injected to produce the same power. As twice the amount of liquid has to be injected, the cooling effect is huge, resulting in over-cooled combustion chamber, limiting the BMEP. A 100% methanol engine has to use multi-spark ignition system to ensure the mixture is constantly being re-ignited due to the cold combustion chamber. Within those constraints, there is still huge potential of power increase.

A good compromise to inject a percentage of injected into a gasoline engine. This will ensure good inlet and in-cylinder cooling effect, but how much? From reading many results form various forums, it appeared to be between 10-30% to fuel. Unfortunately, the results were not consistent, some got excellent power increase, some experienced engine knock, some misfires and some with very low EGT. Why?

4-5 years ago, AI system was very basic, at a certain manifold pressure, the pump starts and deliver a fixed amount of alcohol into the engine. In those days, results have always been very consistent and yield excellent power increase. But for the past few years, the results have been a mix bag. I could only put this down on the availability of the 2-dimensional AI controller. They are termed as an electronic progressive AI controller. Method of delivery is very similar to the mechanical rising-rate fuel pressure regulator. The flow is governed by the pump speed, the controller reads the manifold pressure via a MAP sensor, translates to a PWM drive signal to the delivery pump.

Lucky for some, the availability of stand-alone, piggyback type of engine controllers give user a high degree of control, changing fuel and ignition timing is a merely rapping a few keys on the laptop. In my view, I think this is the reason for the inconsistent result – user’s interpretation of quite a complex ratio of methanol and fuel. Taking fuel out of the factory ECU to accommodate a methanol delivery system that has no reference to RPM, is a tall order. There are a few guys on this forum have managed it, I take my hat off to them.

My personal view on this relatively new concept requires a great deal of patience, dyno result means very little compared to logged data. Dyno-graphs always cause argument. I would really hope to see more logged graphs with AFR, Methanol flow rate, and EGT. If possibly include a second to fourth gear run-up so we can spot the afr change due to Methanol. For those who has just embark on the WAI, tune with 100% water - W50:M50 - 100% methanol and lastly 100% for ultimate power.

Sorry for submitting such a long post.

 

NOT if your meter is set to *Petrol AFR* scale, like most of them are

There is a thread started up in single turbo section for *everyones benifit* go have a read of it

Peter

 

Great read, Richard. Mind if I copy this over to another forum and quote you on it?

B

 

Can anyone tell me how to edit post? I have made a few typos and would like to correct it

BDC, I have no objection but please correct my typos before posting to another thread, it was quite late at night when I wrote this.

 

Welcome Richard...

 

on the way to get some fuel this morning i decided to put my money where my mouth is ( so to speak ) I have been wittering on about the fact people dont go lean enough.

I have leaned out my fuel map in my full boost cells.
so I now have in afr ( for the masses )

P18
--------N11--N12--N13--N14--N15--N16--N17--N18--N19--N20
-AFR--12.5--12.4-12.3--12.5-12.4-12.8--13.2-13.0................
-EGT--683---717--724--702--736--766--781--664.................
KNOCK 21---31----32----40----40---39---40----38..................
INJ------53---57----64----69----74---76---76----77.................
IGL------17---19----21----21----20---20---21----23..................

This is with 50:50 so far. This fuel map will also save me some time on the water map.

The egt's are the result of about 4 full pulls. Im not talking 3rd gear full pulls. I mean from 2000rpm in 2nd gear up to 5 th gear n18.
I cant take the tuning any further till my plugs come from RX7.com. My current ones are playing up.

Scott

 

Very informative post richard! I was wondering if you could go more in depth with 50:50 ratios or any ratios for that mater. I guess what i really would like to know is that obviously by mixing the two substances the properties of the two change correct? So what exactly is the benefit to having a 50:50 mix? Does the fuel when diluted with that much water even burn? Also I'm no tuner by any means and I'm sure wherever I go to get my car tuned is not going to sit there and tune for an 80-20 mix of meth so that is one of the problems i have with going full meth. So my question is for tuning with strictly water is it easier? What are the right monitoring tools to use (ie egt guage, wideband etc...) and I'm having an issue with your statment about when tuning with watet. you say to add as much heat as possible (aka cylinder pressure/boost) and then once your at that peak then you add water to drive the egt's and AIT's down. So is this like a stair step effect? You just keep doing this process over and over until you reach your desired power or until you just can't grab any more heat out? Thanks for any help you can give this newb.

 

I may be able to help answer some of these.

Methanol has a very low vaporisation point. Methanol will also mix with water. Once it has mixed with water it will not seperate. The only way to seperate it is to either distill it or add it to petrol which will displace the water.
Im not an expert in the chemistry but i think the benefit you mention is in the fact the liquid will atomise quicker and also in a lower temperature. Howeva the down side of this will be the extra amount you will need to inject.

It will also give you a colder air charge. in effect you will be getting a 2 part cooling effect because there is 2 chemicals. The meth will cool the air charge and the water will help to improve the BMEP conditions to enable you be stick more boost into the cylinder.

I run a egt which i log on my datalogit with a LM-1 wb02.

I dont think he means that you peak out the incylinder conditions more raise the flow with the boost and reap the gains.

Scott

 

scott,

what boost is p18 and where is your egt sensor.

i should be testing monday at 20 psi and have removed another 5% fuel.

howard coleman

 

16.5 psi. The egt is in the former 02 sensor hole.


Scott

 

thanks for explaining that to me it's a big help. So do you run any sort of knock box or anything? I've going to be logging afr as well as egt's and was wondering if I should take it a step further and monitor knock.

 

go away Peter, I have had enough of you and your condescending attitude. You dont know me, so take your petty judgements somewhere else.

 

Basically i run the fc datalogit software so i can log knock etc while i tune the car. I have set the heat light to warn me if the knock goes up. Other than that i dont need to monitor much.

Scott

 

I run the MSD knock box, seems to work fairly well!

 

thanks guys. I've been looking at the msd box and it looks pretty good as well as it seems to be priced pretty well. I'll put it on my list of things to get. When does the spending stop!!!!!!!!!

 

It dosent!!!

 

What doesnt?