You may have hit on something FTE Fred... the Ford ACT (IAT) sensor can only read to something like 278 degrees F. If he's above that the sensor wouldn't pick that up and the EEC wouldn't be able to compensate by backing off the timing...

 

That's what I'll take time to investigate over the Thanksgiving holiday. I believe that the controller will only take a single 0-5v input and that is just to turn the system 'on' (or so I've read). If it can be used to govern (curve) the volume of delivery, I think I'll be golden.

My understanding leads me to believe that the water/methanol delivery rate should be roughly proportional to air flow. My objective is to tune for maximum ignition advance while maintaining A/F of 11.5:1 at WOT. Normal (non WOT) operation will be governed by the closed loop tables, but I've got to get the water/methanol delivery rates right.

Now Frederic asked for some data: I would be feel better if I had data from more sustained operation but I am seeing IA temperatures for 211-236 degrees Fahrenheit, (after boost) 17psi, for the few second I hold it. This shows the water/methanol injection is working (and working well); I just need to add consistency/stability to the system.

 

Hey Herman! The controller you have can use the 0-5v to progressively increase the water/meth flow (it is a single lead). If you lay the controller flat with the boost port facing towards you there will be a recessed switch. You will want to position the switch to the right. This will cause the controller to work entirely off a 0-5v lead.

Once you do that the controller will work the same as it would if you were using boost as an input. The controller label says 0 - 30 psi so you will have to mentally convert the numbers into voltage. For instance, 15 psi would be approximately 2.5 volts and 30 psi would be 5 volts. Use the green **** to set the activation point and the red **** to set the max flow point. You will get a progressive flow between those two points. You can always use the tune **** to restrict the maximum chemical flow.

If you have any questions feel free to give me a call. Hope you had a great Thanksgiving!

- Nathan

 

That's exactly what I needed to know.

 

Yes, while maintaining the air/fuel ratio you desire for maximum power at a given RPM. Your idea of 11.5:1 at WOT is probably very close to ideal. Most beginner tuners don't approach this figure under any circumstance and why they end up run their forced induction vehicles so lean - which causes many other problems aside from leaving potential power on the table unused.

My initial guess was that your intake charge temps were too high - or at least above what the EEC can perceive. Since the IAT maxes out above the readings you've presented we can eliminate that entirely.

I am curious about how much water/methanol you're injecting as compared to gasoline/air - because too much is not exactly ideal either. I'm not sure if you're at that point yet.

I also asked if you have an intercooler - did I miss your answer? I ask mostly because I'm of the opinion the bulk of the intake charge cooling should be done with an appropriately sized intercooler *first* - then use the water/alcohol/methanol/whatever mixture to pull the temps down a little more to keep things below the detonation point. Gasoline burns by far better than a water/methanol mixture and that's the substance you're going to make the bulk of your horsepower from.

Just to give you an approximate ballpark... my old twin-turbo dodge pickup (451cid stroker) ended up with no more than a 1/4 (by volume) of a 50/50 distilled water / industrial grade isopropol mixture as compared to gasoline which made up the other 3/4ths.

I found, at least with that engine, application, and the way I treated on the asphalt that a mixture 3 parts gas to 1 part "other" was pretty much the limit as to where I could maximize horsepower, and this only "kicked in" above 5500 RPM. Maybe it was 5000 RPM. I forget, it was many years ago. But to much resulted in lower power.

You might also play with the mixture - water versus flammable substance (methanol, isopropol, etc) in your secondary system. While I kept a 50/50 mixture for my Dodge that was mostly out of laziness. I have friends who have enjoyed good results with more water and less flammible substances, as well as the other way around, as much as 70/30 or 30/70. Of course all these projects have different displacements, compression ratios, applications and uses so I can't really off the top of my head give you a hard-fast rule as to what works best for what.

Do you have any way of measuring exhaust temps?

If not, after an extended WOT run do the manifolds change color at night where you could actually see the difference?

 

I have no idea of the mass of water/alcohol in proportion of fuel as I have no means of measuring. I suppose I could do some estimating based on nozzle size and flow rate of the pump and such but my confidence of the measurement would be slight at best.

"I" can't intercool my application because the KB discharges directly into the plate manifold that rests on the factory lower intake. There's just no way I (and I think you might even find it a challenge) could fab something up, which is why I became so enamored with the AIS system. If I had a Triton motor, I could use the IC from the Lightning but the 32V Intech motor's heads differ.

Here's some *gross* figures on alcohol to methanol: 70/30 - more ignition lead less power, 30/70 lowest IAT can't get enough ignition lead. 50/50 *seems* to be about the best of both worlds. Given the high price of pure methanol (in gallon quantities) I have purchased a silly quantity (6 cases) of Peak washer fluid and use my hygrometer to adjust the desired proportions.

It’s funny you should ask about this as the flammability of the mixture has been of curiosity to me. Given that I live in a college town that has a pretty decent engineering school I’ve enlisted the advice of some of our professors. While it turns out that you can simply throw water on an alcohol fire to put it out, any proportion of alcohol in a water alcohol mixture returns to combustible alcohol after the state change from liquid to vapor. According to these guys, I’m working two sides of things in varying the ratio: More alcohol at higher octane allows greater ignition lead and power but the relative mass of the intake charge is reduced due to alcohol’s lower latent heat of vaporization. Alternatively, a greater proportion of water increases the density of the intake charge (being able to pull more of the added heat out) but at the expense of having less detonation resistant fuel and increasing to the point where the distribution of vaporized water molecules interferes with the flame front in the cylinder. [At this point they started writing equations on the whiteboard that escaped me and I’m a pretty well educated guy.] To sum up, these guys suggested that at least under full throttle operation I should try to tune the system and take gasoline out replacing that fuel with a high proportion (and higher volume) alcohol/water mixture.

It was great thought experiment; however, at this point I’m thinking back to my dual-fuel (a second set of injectors, plumbed to a separate high octane fuel source) idea.

I’m guessing that I could adapt some diesel application’s (what are they called, pyrometers?) to my manifolds to get the EGT’s but was not sure if a gas motor’s EGT’s are comparable to a diesel’s and I’m unsure of the quality (fidelity) of the measurements (we all know just how peachy those cheap A/F meter’s measurements are)… This too was one of the professor’s topics. He wrote a technical paper (this guy’s from the aviation school) and suggested that I should tune to just lean of peak EGT. He admitted that his paper was more on the subject of brake specific fuel consumption in piston engine aircraft operating at a relatively constant speed, but he detected my desire to not only make power but to do so most efficiently.

Now here comes the earth shattering news. Although I was off last week I didn’t get any time to play as I was too busy wheeling and dealing. On Friday, I very well may have a new toy that will likely reduce my interest in this specific application. I’ll give you a hint; it begins with GT but doesn’t end in 500. Let’s face it here, no matter how much power I get out of the motor; it still sits in a nearly 6,500 pound vehicle. Quick? Sure. Surprising? To many. But fast? Not to the folks that do it regularly. Friday may change that.

 

No reason to be lacking in confidence my frined, it's just math. For a crude ballpark it shouldn't be that bad.

It's not like you're going to waste your time taking the shape of the pintle/seat of the injector, the viscosity of the fuel for a given temperature, and the ramp time of opening and closing cycles of the injector and other such factors

You could even use the flow ratings of the injectors as a basis from both the fuel injectors and the alky injectors, then compare flow based on the pressure behind it combined with pulse width.

Is it this particular kit, or at least close in arrangement of the parts?
http://www.kennebell.net/supercharge...ting54_26L.htm

If so I can see why you don't have an intercooler. I do have a solution for you if you're interested should you have the time/interest or cash to pay a shop to fabricate. I can bore you with the details if you're interested. If not that's entirely cool also.

and one of my curiosities also however I am just a monkey so I've avoided such equasions and try to solve such problems through testing on various vehicles I've been asked to play with. Through experimentation we've gotten good results for each vehicle, though it's more of a trial and error process with it being known that if the pistons go the wrong way, I'm not available for further questioning. I and several friends did a lot of these type of experiments on junkyard engines on an old rickety engine dyno to see what happens. I can't say that we gathered any seriously correct, accurate data but we did manage to accumulate some ballparks and blow a lot of stuff up.

I found that to be the case with the TT 451cid dodge truck - to a point - if I crossed that point power noticably went down - and my "guess" was that there was too much non-gasoline substances in the chambers. Though you could have eaten off the pistons they were so clean.

Did I post the monkey rigging of this Dodge truck on FTE? I must have. Anyway, I had three fuel rails per side - two for gas, one for alky/water. Three fuel pumps. 24 injectors.

One could also ballpark this by doing a really hard, extended run, then pulling over immediately and measuring the temperature of the exhaust manifolds (or header tubes) just as they bend away from the direction of flow from the heads - i.e. the first bend in the system. That won't give you a "dead on" figure but it will get you reasonably close.

Bring him over here to NJ for drinks.

I think there's validity to what he's telling you because Carroll Smith in the various "to win" series also talks about exhaust temps in this manner, though again, my being a "monkey" leaves me in the dark with some of the discussions. I've developed my own method for tuning forced induction vehicles, and that's to start off as rich as possible where the vehicle starts (even if the idle has to be ridiculous), then work backwards across the RPM band to get things where they should be. I typically end up about 11:1 air/fuel at WOT every time. I have assumed that's not coincidence. That's not based on anything other than dyno results and the much more common ****-o-meter.

Congrats on the new toy. I assume it comes in red, red, or red.

And you're right, an incredibly heavy vehicle with the aerodynamics of an office building requires a lot more power to achieve the same acceleration of an import with nitrious at 1/3 the weight. It's always been about power to weight ratios... regardless of vehicle.

 

My only question is why not a GOOD piston?? Seems like he went to alot of trouble only to have the piston be the weak link. I also dont see how they could withstand 40+ pounds of boost.

 

Why would you say hypertueric's are not good pistons?

They are stronger than most forged/cast pistons, and by far more stable dimensionally, which promotes better sealing of the rings as you can machine the tolerances that much tighter. Less blow-by results in more power.

They are more brittle, which of course is a disadvantage if your engine is suffering from detonation problems.

 

Black, Black, Black.

Although I agree with Frederic I thought I would add: http://en.wikipedia.org/wiki/Hypereutectic_piston

And also: Frederic, if you are referring to yourself as a 'monkey' in a humorous sense, than I'm all right with it. However, you may not be aware that many folks here look up to your experience.

 

From the article: "...The “4032” performance piston alloy has an approximate Silicon content of 11%. This means that it expands from heat less than a piston with no Silicon, but since its eutectic level of Silicon is fully alloyed on a molecular level, this alloy is less brittle and more flexible than a stock Hypereutectic “smog” piston. These pistons can survive mild detonation with less damage than stock pistons..."

Thank you for posting that, because I was unable to find the specific alloy designation for the specific pistons I prefer in forced induction engines.

BTW, it's been my experience that "mild detonation" needs to be really mild. A few good knocks and you have holes.

Thank you for the compliment but I was half-serious as I am not an engineer nor do I have an engineering background. I am merely an enthusiast who drinks way too much coffee and spends a lot of time reading and researching, and have been doing so since my late teens. My fascination with technology does not equate formal training or documentation of any kind (bachelors, masters and doctorates).

But I do enjoy experimenting and seeing "what happens when you do this?". Some of these experiments are less useful than others. Like running a Chevy 305 on "Zep". And no, the exhaust didn't smell like oranges.

 

Just what do you think us Phd's do? Just becuase you don't have the paper doesn't mean you're not a member.

On a sad note, no GT-40. I may be well off but not well enough to afford the $10,640 a year for 1,200 miles or less.

 

Thank you, but I'm not a member. I'm a monkey. Pass the bananas (and coffee!)

Build a chassis, buy a GT 40 replica body, and make one for 1/5th the price and you can put any engine you want in it!

 

As you stated, they're more brittle and wont handle the detonation. Unfortunatly, detonation and forced induction go hand in hand. Lets face it, it happens and alot more than it typically would on a n/a setup. As far as better ring sealing... maybe I misunderstand what you're saying but, with a nitrous and/or boosted motor you set a wide ring gap. Under "normal' driving you will get blow by. Under boost it seals up nice and tight. I think if the hypereutectic piston was the way to go on nitrous/ boosted applications we'd see more engine builders using them instead of the more expensive forged pieces.

 

Ring gaps...

Larger ring gaps? Forgive me while I rudely spit coffee through my nose

As you stated larger gaps increase blow-by and that in turn reduces performance across the board because of lost compression past the larger gaps. This also contaminates the oil which destroys its effectiveness as a lubrication in addition to circulating blow-by solids (carbon, sulfer dioxide) into the rest of the moving parts, taking bearings and bearing surfaces to destruction. These solids are often smaller than what the oil filter can remove, and they cake nicely on edges like one would find on main bearing grooves.

How can any of that be good?

This is why to those who ask I always recommend total seal brand top and 2nd rings. For oil rings I may use theirs or something else depending. I prefer their MX series if they are available in the bore diameter - in my opinion they seal the best of all their products with forced induction and nitrous applications.

There are other solutions as well. Make (or have made) rings that have long, overlapping tapered ends. No Gap and still can handle thermal expansion.

One can even do the low-buck monkey method - install two 1st rings, one on top of the other with their wide gaps 180 degrees out of phase. Most engine builders will recommend against this practice but it works very well for lower RPM, large bore engines, forced induction or not. Not so good on small bore, high RPM squeekers.

hypereutectics & Detonation...

Before we embark on the great piston debate (which I would enjoy) I think for a given engine we should be asking ourselves this question, and this question only:

"Why does this particular engine detonate?"

Detonation indicates something is wrong with one or more of the following: design, assembly, tuning. Building an engine to survive detonation while may be smart for a variety of reasons is not actually solving the real problem - just masking it. Detonation reduces horsepower and breaks parts of any kind, and should be avoided.

Modern engines use aluminum pistons that move in a steel sleeve or iron cylinder. Typical piston top temperatures are around 600 degrees, which is more than enough for the aluminum pistons to expand noticably in the bores. The bores do not expand anywhere near as much. Therefore, to have the clearances tight during the normal operating range the pistons have to be undersized a bit so when they heat up, they don't get stuck in the cylinder bores. You get piston slap during cold starts this way.

Since hypereutectic pistons have a high amount of silicon (typically 15-19% ?) they do not expand very much at all, allowing for a much tighter piston to bore clearance when cold as well as operating temperature. I've heard of clearances as small as 0.00075". That's a fairly tight clearance, wouldn't you agree?

Hypereutectic pistons have a weight advantage as well - they are a bit lighter than their "ordinary forged" counter parts. This allows the engine builder to select slightly lighter rods and shave off a fair amount of material off the crank's counterweights. These things combined reduces the rotating assembly's weight allowing for a faster accelerating engine. When shaving the crank's counterweights, one can also create a bit of a knife edge allowing it to slice through the syrupy oil that in turn also helps with crank speed acceleration. This may not be considered "critical" in a large heavy truck engines but in a small car with a high redline engine this is probably deemed more important. It's certainly mission one on an all out race engine that must accelerate and decelerate (road rally, F1, nascar, etc).

For all the advantages one can gain from Hypereutectic pistons I am unsure why more engine builders don't recommend them so I cannot answer your question specifically. Maybe because 15 years ago they broke all the time and there were a lot of problems. These days the metalurgy and manufacturing processes are so much better and some companies even started to have a clue and make their piston decks a little thicker to compensate for the concern of fracture.

But when it's all said and done, no engine should experience detonation if it's designed, built, and tuned correctly. There is nothing wrong with building an engine to withstand a fair amount of abuse from detonation, but it doesn't solve the actual problem - why the detonation is occuring in the first place.