Hotrod has posted this link on another forum, it is extremely good reading... recommended

http://enginehistory.org/Frank%20WalkerWeb1.pdf

Richard

Good reading :D

I guess some of Frank's last inventions (end pages) might be of less interest to this forum:
A non-slip stacked paper fasteners
A urinary tract catheter that allows flushing and treatment of the prostate gland. :lol:

I was very surprised about the isopropyl being useless. :shock:

In their setup, it was useless because it was making the mixture too rich to ignite.

This may not be the case with our setups (injection, ECUs, widebands, etc) :wink:

I had been reading thru this topic few times now trying to get a grip. I have some thoughts to share.
First, talking about tuning new car for WI. It has been mentioned that you want AFR about 12.5 as cars under boost run normally richer. Well here is a third gear pull of my car. It?s totally stock:

http://img228.imageshack.us/img228/1434/afrdy7.jpg

AUDI 2002 model 1.8 Turbo
Max boost hit early about 7PSI@2000RPM. After 4500RPM there is boost reduction due to turbocharger going outside efficiency range at the same time AFR seem to be becoming richer. This does not correspond with max torque band as it is 2500-3500RPM.
Look like new cars run lean stock. My cruising AFR is 14.7@ light load(80Km/h)

Second, according to stock ECU knock sensor reaction KNOCK been detected throughout whole RPM range. Under knock I mean not audible knocking but early knock detection by ECU(mild knock). Here is Correction Factor data log:

http://img81.imageshack.us/img81/9291/knockgq5.jpg

CF1,2,3,4- timing pull back by ECU due to high knock sensor activity.1-cylinder number one and so on.
BTDC ? ignition advance.
You can see as CF goes up ECU pulls ignition down. This present equally thru whore RPM range not just thru max power band. This would mean that WI have to be active thru whore RPM range. During normal cruise there is no CF noted. It only appears under the boost and can vary from during whole RPM range to showing up here and there. There is no consistency in knock. Looks like it is very unpredictable but load dependand. It is also noted that poor fuel quality will make it more intence as well

Any comments anyone?

We are not talking stock cars here mate, the manufacturer has optimised all parameters during stock operation.
If you inject water on a stock car you are unlikely to make any more power. Most likely you will *lose* some.

How do you know that? Are you datalogging the solenoid's duty rate?

That's how it's meant to be.
It is high throttle/high load conditions that AFRs are meant to go richer.
Are you talking about the knock sensor output, or the ECU's interpretation of Knock? These are two different things, the sensor produces output all the time, the ECU has filtering algorythms to make sense of it all.

this is very true.
However, I doubt that you are getting any knock on a stock car running stock boost and the recommended fuel. Even if you do it will be on a very hot day and at max torque revs if you boot it real hard. The ECU will adjust timing a bit and that's that.

AUDI has ECU which is slow to adapt. As I always use high RON fuel it adopted to it. Accaisinally I put "normal" fuel recomended by AUDi for datalog purpuse and i notice that a lot more knock is present on datalog. It takes about one full tank of fuel for ECU to re-adapt to new petrol and ajust it's map to suite.

You need to run more *boost* as well.
If you stay within stock levels then power gains will be minimal.

One way to push the turbo beyond the 'normal' limits, without compromising efficiency is to inject before the turbo, at the 'eye' of the compressor if possible. It is regarded as experimental, but boy does it work. :D

That is slow indeed. They tend to be conservative, protecting the engine if fuel is suspect, we can't blame them for that, can we? :wink:

Try injecting 50/50 water/methanol and see how it goes. Even with a small jet (0.4mm) operating at 4psi (pretty low boost level by the standards here) knock should disappear, even if you push boost up to 1 bar.
If you are still seeing knock, then it's probably noise that you're registering, not real knock.
...or your fuel is of very poor quality indeed :shock:

Re: Tuning for water injection: fuel, ignition, and EGT
 

I would think that a safe AFR would be based on the amount of meth injected. Not to sure how a mixture of water and meth would play into effect since I have only run meth. Stoich for gasoline and meth are different. With that in mind more meth means a richer AFR. Well at least this is what I see on my car, the only problem I have is that I am spraying the same amount of meth at all boost levels, since it is a single stage injection that turns on at 20psi. It does seem to have a bit of lag down low and maybe it would be smart to run a leaner mixture at lower RPMs to help with spoolup. It is something I have been thinking about but ran out of time last year since my car is not driven in the winter.

When it get nice out I am going to attempt to run one more jet and hopefully 3-4 more pounds of boost.

Victor

97 GSX, 32 psi with 1.0 & 0.8mm jets @ 100psi with 93 octane, roughly 12.8GPH.

Hello,

First of all, this is a great post!

For me, this graph below has been very informative with regard where to tune for.

http://images.thesamba.com/vw/gallery/pix/435515.jpg

regards,
Walter

Re: Tuning for water injection: fuel, ignition, and EGT
 

Wow Guys, I feel so much more smarterer.

What a read.
Way too much for me to absorb it all.
But my general gist of it all is:

50/50 water methanol mix is best "all round" ratio.

Tune car for max power at best air/fuel ratio without knock with no injection (12.5/1)

Add injection and then reduce fuel to bring air/fuel ratio back to optimum

Advance timing to gain more power to just before knock

For more power after that either add more fuel or injectant

Have I got that right?

I am off now to soak my head in a bucket of ice water for an hour or so. LOL

Re: Tuning for water injection: fuel, ignition, and EGT
 

First few pages in this thread are gold, roll back 2004. Where are these people now?

Anyway I can tell you in a practical testing environment allot of what is discussed as theory or quoted from 80 year old tests does hold true in a real modern high speed internal combustion engine.

WI does indeed take a fair bit (no scrap that ! allot of) knowledge and testing to extract the most from this quite complex science. From personal experience there is much to be said for testing testing then testing some more~! I know the years of work I have done has gained me so much knowledge in this subject and so much of it is hard earned, brain frying stuff, its a stressful job some days, as you are doing things no one else (or very little) can achieve, cause its hard, it takes time, money, analytical ability and a certain level of relevant education to have a hope to repeat what many great engineers found since way back to the 1880's (yes first tests on WI!)......

I love the topic and the science, its my most enjoyable area of research for the above listed reasons and many more :) once you get aligned with the great resources Richard has collated here and many other valuable members have linked or posted of their own testing you too can be on the very rare bandwagon of capable people who don't need "power in a can" to look great :) Lets face it, anyone can open their wallet or extend a bank loan to pay for race fuel or some other rubbish that eats injectors or fuel system parts, but very few men can actually say that they have fast and reliable and mega powered cars running just normal gasoline/petrol............... that is priceless, just like this forum and the science that is water injection

Re: Tuning for water injection: fuel, ignition, and EGT
 

I was hoping for an answer to this question. I run J&S safeguard on two heavily modified engines, one a Cosworth YB and one a Porsche 930, 3.5L twin plug both with stand alone ECUs (Performance Electronics PE3's).

I can therefore say I know quite confidently when these motors are running close to or at the knock limit. Now, I have not dynoed these cars to see if I am beyond the MBT and might actually benefit from reducing timing, but in my experience, most heavily boosted cars I have had were knock limited in terms of power delivery. I have ordered water injection kits of both cars, and was going over my 'strategy' for tuning with it. Initial thoughts were just like Richard mentioned above....essentially run timing up higher, and maybe set AFRs at 12 to 12.5, watching EGTs and keep a few degrees away from knock on my water injection timing maps. Would you guys agree? Obviously, I should probably get them on a dyno, but I probably wont get round to it.

Re: Tuning for water injection: fuel, ignition, and EGT
 

It depends. Given a high octane base fuel, enough water meth, effectve nozzle location and a well designed combustion chamber/piston/squish etc. you might hit MBT before any knock occurs. If you plainly map to the knock limit, you might seriously overload your engine.
Most engines today run a rather high compression ratio and often hit knock before MBT.
My strategy (supercharger) was always to start with reasonable low timing, get the AFR you want and then increase timing step by step and feel if power increases. If either power does not increase anymore or knock occurs, you have hit the limit.
On a dyno, you can see rather small changes. The butt dyno works well enough for street use. If you do not feel any increase anymore, it is not relevant anyhow.
In terms of amount of spray, I found with my latest direct port nozzle location right before the fuel injectors on the top side that the more flow I dailed in the more extra power I was able to extract after adding timing. When I improved squish I found no more improvement past a certain amount of spray despite a increased compression ratio. I seems I am no longer knock limited. :-)

Re: Tuning for water injection: fuel, ignition, and EGT
 

Thank you Rotrex, that makes sense. I think the J&S safegaurd, if calibrated correctly will alert well before serious knock occurs and it can pull out up to 2degrees per engine cycle on a specific cylinder, up to 20degrees. I think this unit keeps me well away from serious knock, but always better to be safe than broke....those 930 engines are not cheap to do properly!

Re: Tuning for water injection: fuel, ignition, and EGT
 

I use a J&S, too. 20 deg is too harsh unless you have a very slow burning combustion chamber design, e.g 60ies to 70ies Hemi heads etc. 10 deg worked best.
With the J&S serious knock is well captured. You can still hear it and also feel it from the power loss of the pulled timing under boost. I usually use it to point me to the map spots that need some correction. I had a pump issue once with the priming pump controller of my Aquamist 2c not working properly anymore and the J&S had some serious work to do as WI essentially failed. The engine spit blue flames from the exhaust with serious misfires as the J&S pulled 10 deg on all cylinders. That was a nice light show on the gauge. But nothing else happend.
As I am converting to an other engine I have sold my current engine and J&S last week.
The J&S is not as smooth as a fully tuned factory knock control system, but it does its job to indicate knock and provide some monentary correction. For street tuning, it is very very nice to have.
I would not "run" on it as in dail in full timing and the J&S does the rest.
I still can recommend it. It is 1000% better than having no means of interventing on highly strung forced induction engines.

Re: Tuning for water injection: fuel, ignition, and EGT
 

Completely agree. I will only use the J&S in the 10degree total / 1 degree per knock event mode, and never really lean on it heavily to pull timing under normal conditions, but it's nice to know it will be very aggressive in pulling timing if it has to, and also seeing the gauge go nuts gives plenty of knock warning.

Re: Tuning for water injection: fuel, ignition, and EGT
 

I just wanted to highlight what I believe happens with the Mark 5/6 VW Golf GTI and the Focus ST; both have the Borg-Warner K03 turbo charger.

With the stock wastage and stock inter-cooler (those would like to believe) is poor are cooling the stock turbo when average off the shelf tunes are employed that removes the timed over-boost and makes that max boost (21 psi in the Focus ST's case).

I am running the car right now when drag racing with 40% Ethanol mixed with 91 octane fuel (California). I've seen max of 26 degrees of timing. Once the car reaches 210 degrees coolant temp, it reduces timing by 9-10 degrees and I loose about 1.5 mph in trap speed.

With an aftermarket internal wastgate, it's no so much how much more boost you run, but how long you hold it. On the stock WG that's about to 4100 rpm at my tuned boost of 23 psi and bleed down to 15 psi, a product of the stock spring in the WG.

With a Turbo Smart IWG with the standard spring for this car, it will hold 20 psi. The problem is that the turbo creates much more heat doing that. To combat this I know of two tuners of the car that tried this -

One complained about having to use increasing amounts of ethanol mixed with the fuel in order to keep the timing they increased initially (tuned car), at that point 30% (E30) and still got some knock, so they kept turning the boost down via the wastgate solenoid until they reached about 16 psi.

That's ironic because that's about where I am know. I maxed out the pre-load on my OE wastegate to about 3 mm. The car will hold 23 psi about 700 rpm longer.

The result is I picked up 1.7 mph with full timing restored (car about 200 degrees after my burnout). I know exactly that much because I did another pass about 30 mins later which is not enough time to let the car cool, and it went 100.44 mph when it previously went 101.96 mph.

I should mention the car is stock ATM, it only has a tune. A car with a 91 octane tune will barely crack the century mark at the drag strip, but most run 98-99 mph.

I did that with my base E30 tune (99.82 mph) and with a bit more timing advance on 40% ethanol it's run 100.25 mph. The truth is the car could have run 100+ mph at any time. I've only had five months and it has 30+ passes on it but I am just figuring out the proper shift points.

Anyway, the other tuner runs a Turbo Smart IWG and has achieved the elusive 300 whp mark with 35% Ethanol.

He won't divulge how much boost he's running or how much boost he's holding (I asked). He sent me a message that if I replaced my current tuner with his services he would spill the beans but to only paying customers. He didn't say the last bit like that but it was implied.

I purchased the same IWG and added W/I (AEM) to be able to push the stock turbo at least as far as he was able too. It's also the reason I went pre-turbo and post inter-cooler with my W/I system.

Re: Tuning for water injection: fuel, ignition, and EGT
 

I'm running an aquamist HSF-2 kit for my JDM 2006 Subaru STI. injecting only water at 42% IDC onwards. car runs great!

but i realized that there is a very very minor knock during initial injection and it's persistent throughout my logs. should this be of a concern or is there anyway to totally eliminate this?

thanks.

Re: Tuning for water injection: fuel, ignition, and EGT
 

Knock has to be one of the most mis understood terms in the after market performance world.
Typically when an engine is raised in power its vibration recorded through the acceleration sensors will go up (knock sensor), the shape and amplitude of these traces and the zero cross over point can be literally traced within a couple of CA to an in cylinder pressure transducer!, so its a very accurate representation of what is happening inside the combustion chamber.

As the BMEP goes up the 'knock' goes up, this all has to be defined in the ECU you chose to run, some do this better than others, some work, most don't! I would say so far that in all the ECU I have used (not owned or paid by anyone but out of my own pocket!) there is only ONE ECU that you can buy that does this properly and its made by Life Racing in the UK, all the others I would not piss on personally. Why does it work??? they build their own engines that race in LMP1, they are running on knock limit all the time, and they just work as intended, unlike the spec sheet racers with glossy web pages and blogs etc.

Now having got that out of the way and back onto your question.
You need to know what is normal what is not in your own engine, or otherwise the severity of the events, this is easy to define with nothing more than an acceleration sensor and some experience and the correct electronics that have a history of management in the real world at the peak of competition, if your own stuff you run does not meet these then its hard to honestly rely on the information you are being presented with. And note if someone tells you to use audible knock tools then put them in the *fuck head basket* never ever to be consulted with ever again!

Knock has to be quantified and acted upon within one engine cycle, you need to know what it is, if its normal, and where its heading (towards pre igntion) and countered at all costs, the importance of this varies with heat release or potential energy in the chamber IE: the more power it makes the more critical it becomes, some engine types when stressed will fail catastrophically and instantly when moderate levels of knock are exceeded.

Final note, some knock is good! generally the closer any engine runs to destruction the better its performance will be! so its not uncommon with Life Racing electronics to run the engine on the verge of this point all of the time to extract the most power and highest efficiency. Water Injected cars will allow you to run closer to this point without then quickly leading to pre igntion, this is no one really talks about, but is one of the key things that WI allows (not higher ratios of meth than 50% cause that will lead to far inferior performance FYI). So its a long reply but is normal to have light levels of 'knock' and its a healthy by product of an optimized engine. If you levels are right I cant say obviously as that information is not at hand and not validated.

Re: Tuning for water injection: fuel, ignition, and EGT
 

I was told, when fine tuning REVO software for VW's TFSI engine, the guideline stated to keep adjusting the fuel, timing and boost until the knock retard value reads -3.0 because that's when the engine makes the most power. Maybe it is safe to do that in TFSI engine which comes with forge piston standard.

Re: Tuning for water injection: fuel, ignition, and EGT
 

On my STI, I find 42% IDC (12 o'clock position) is a bit too late and choose to go for 10 o'clock which injects at around 25% to 30% IDC (I need to look at my HFS3 flow vs FIDC flow datalog). But I am using TMIC so injecting sooner is never a bad idea and I never saw any knock correction.

What is the value of you knock correction during the initial injection anyway? -1.4?

Re: Tuning for water injection: fuel, ignition, and EGT
 

base on my datalogs injecting at 25%-30% FIDC is around 300-400rpm earlier. what benefits are to be expected for injecting earlier?

yes, the knock correction is -1.4 during the initial injection. few days back i tried advancing more timing where knock is recorded during initial injection, and its at 0 knock now. perfect!