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resago
10-05-2008, 12:37 PM
The ECU uses lookup tables to determined the amount of fuel to inject based on MAP/MAF,IAT,RPM readings. It can even have a different table for each gear. This also applies to timing.

It then looks at the O2 sensor to see if the values in its tables achieved the AF ratio it wanted. This does not apply to timing.

So you can't just modify the input (MAF/MAP/IAT) reading because the computer will eventually adjust fuel inj based on the O2 sensor. This amount is called the Long Term Fuel Trim(LTFT) adjustment.

you can't feed a constant signal to the o2 sensor because under acceleration, it expects to see a rich condition, and at cruise, a lean condition.

this explains why when you do a map/maf mod, you see short term gains, but then nothing.

this would also predict that an o2 sensor mod would take some time to take effect.

doing both SHOULD give you immediate and long term results. If you do an O2 sensor mod only, you are not getting the benefit of altered timing.

More later.

hg2
10-05-2008, 04:13 PM
The ECU uses lookup tables to determined the amount of fuel to inject based on MAP/MAF,IAT,RPM readings. It can even have a different table for each gear. This also applies to timing.

It then looks at the O2 sensor to see if the values in its tables achieved the AF ratio it wanted. This does not apply to timing.

So you can't just modify the input (MAF/MAP/IAT) reading because the computer will eventually adjust fuel inj based on the O2 sensor. This amount is called the Long Term Fuel Trim(LTFT) adjustment.

you can't feed a constant signal to the o2 sensor because under acceleration, it expects to see a rich condition, and at cruise, a lean condition.

this explains why when you do a map/maf mod, you see short term gains, but then nothing.

this would also predict that an o2 sensor mod would take some time to take effect.

doing both SHOULD give you immediate and long term results. If you do an O2 sensor mod only, you are not getting the benefit of altered timing.

More later.


The signal voltage coming from the efie is just added to what's already going to the ecm,it doesn't make it remain a constant. What ever voltage is already coming out of the o2 sesnsor remains the same plus what ever voltage the efie is adding and will fluxuate with acceleration and back down to idle just like it always has,but also carrying the added voltage.

jacobnbr1
10-05-2008, 04:20 PM
The ECU uses lookup tables to determined the amount of fuel to inject based on MAP/MAF,IAT,RPM readings. It can even have a different table for each gear. This also applies to timing.

It then looks at the O2 sensor to see if the values in its tables achieved the AF ratio it wanted. This does not apply to timing.

So you can't just modify the input (MAF/MAP/IAT) reading because the computer will eventually adjust fuel inj based on the O2 sensor. This amount is called the Long Term Fuel Trim(LTFT) adjustment.

you can't feed a constant signal to the o2 sensor because under acceleration, it expects to see a rich condition, and at cruise, a lean condition.

this explains why when you do a map/maf mod, you see short term gains, but then nothing.

this would also predict that an o2 sensor mod would take some time to take effect.

doing both SHOULD give you immediate and long term results. If you do an O2 sensor mod only, you are not getting the benefit of altered timing.

More later.

The computer is too smart for tricking.

The computer is trained to find inconsistancies in the data and counter react for that data and/or spit a DTC for the driveability issue.

Im not saying it can't be done and adjusted from season to season.

If you have the know how you can accomplish this but what I and most others desire is a painless automatic system that already does it for us and the pcm is the answer.

Has anyone ever used the computer in "open loop" mode and tricked it to stay there?

Open loop mode is the part of the PCM that reads only factory settings and those can be adjusted by reflashing the PROM(programmed read only memory) CHIP of the PCM.

From the open loop status the PCM ignores all sensor data and runs on default.

Eventually you will get a DTC for the PCM not being able to go into closed loop though.

I still think the best way for this is to restrict airflow completly as if it never existed thus de-tuning the engine in the 1st place and adding the HOD to gain it back later on down the line after th MAF..

resago
10-05-2008, 05:20 PM
>The computer is too smart for tricking.

like they say its only as smart as the person who programmed. What I am suggesting is to give it a set of data it has a corresponding value for. If the input looks valid, it will go about its business without throwing codes.


>The computer is trained to find inconsistancies in the data and counter react for that data and/or spit a DTC for the driveability issue.

these inconsistencies specifically would be an input with no corresponding output. If you don't give it input outside of its range, it shouldn't throw codes. I see people throwing codes when they modify an lookup input but not a followup input (MAF/MAP and o2). If you do both and don't put the input or result outside of the computers preprogrammed expected response, it should work.

I am looking for how much IAT ties into timing and fuel as well.

jacobnbr1
10-05-2008, 07:36 PM
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1995 Ford Truck F 150 2WD Pickup V8-351 5.8L
Vehicle Level Powertrain Management Computers and Control Systems Intake Air Temperature Sensor Description and Operation


Description and Operation
Notes

Intake Air Temperature Sensor






PURPOSE
The Intake Air Temperature (IAT ) sensor measures the temperature of the incoming air flow. The Powertrain Control Module (PCM ) uses this information to adjust the fuel injection base pulse width, EGR flow, and ignition timing.

CONSTRUCTION
The IAT is a two lead thermistor type sensor with a negative temperature coefficient and is located in the intake air flow path.

Descriptive Schematic






OPERATION
The PCM applies a 5.0 volt reference voltage to the IAT signal lead while the signal return lead is connected to a common sensor ground. As the temperature of the incoming air increases the resistance of the IAT decreases and the voltage drop across the IAT decreases.

A decrease in air temperature will increase the resistance of the IAT and raise the voltage drop across the sensor.

The normal operating range of the IAT is 3.50 volts (50F) to 1.02 volts (158F).

Note : Due to its negative temperature coefficient minor increases in resistance across the IAT circuit harness and ground connections can result in temperature values that are much lower than actual.

RELATED DIAGNOSTIC TROUBLE CODES

DTC 112 - The IAT sensor output is less than the self-test minimum, 0.2 volts.

DTC 113 - The IAT sensor output is greater than the self-test maximum, 4.6 volts.

DTC 114 - The IAT sensor output is out of self-test range, 0.3-3.7 volts.



Some of this stuff don't have outputs...






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resago
10-05-2008, 08:17 PM
awesome, thanks!

jacobnbr1
10-05-2008, 09:19 PM
awesome, thanks!


Let me know if you need that for a specific car?

resago
10-06-2008, 12:54 PM
comparing the tables, which has the most bearing on timing and fuel?

hg2
10-06-2008, 02:03 PM
comparing the tables, which has the most bearing on timing and fuel?

Are you asking which sensor has a bearing on timing?

resago
10-06-2008, 02:17 PM
yeah. which has a bigger influence, MAF vs IAT

hg2
10-06-2008, 02:59 PM
yeah. which has a bigger influence, MAF vs IAT


Got this from a tuning doc I use


IAT
The IAT is less sensitive to cold start issues. You can add more temp to this signal than you can to the CTS. Just keep in mind that you are not only lowering your lean-out limits, you are also retarding your ignition timing. If you put a timing light on the engine as you adjust IAT values, you won’t see the timing change. The timing changes under load. Hotter air is more prone to detonation. This is why the ECU retards the timing.

If you are tuning on the hottest day of the year, you may find out just how high of a signal you can generate before setting codes. Typically it is in the 240 F range. If you are tuning in the middle of February, then you can offset the signal from your base cold reading and things will be fine for now. Come June or August, this setting may be high enough to trip codes. Allow for this when tuning.

the MAP sensor sees a given load, the TPS sees a corresponding throttle angle, the CTS sees a normal operating temperature, and the O2 sensor is saying the engine is too rich, the ECU will comply…to a point. When the ECU has leaned out the AFR (Air/Fuel Ratio) beyond what the programming claims is an acceptable range, the ECU will go into Open Loop and ignore the O2 sensor. It then reverts to Look-Up tables for its source of information. At this point, mileage will invariably go down, and often a trouble code is set.

Consider the conditions needed for the ECU to accept lean fuel commands. If the engine is warmer than it actually is, the ECU will accept leaner. If the engine is under less of a load, the ECU will want to deliver less fuel. If the incoming air is hotter, the ECU will accept lean commands more readily. If MAF (Mass Air Flow) sensor equipped, less air entering the engine will require less fuel.

scirockett
10-06-2008, 03:09 PM
sweet. a good ECU thread!

I always thought the only sane mod (imo) is the o2 mod. This only effects fuel mixture in closed loop (when efficiency is important), and not in open loop (when HP is important).

Does anyone have any data on how HHO effects o2 readings, either narrow or wideband?

how about EGT's with HHO?

My experience with MAP based ecu's shows the fuel and timing maps are primarily based off a MAP vs. RPM table. Intake air temp and coolant temperature will modify timing depending on temps.. ie, high IATs = timing retart and low cts = timing advance (usually up until 30-40deg C for cts). when conditions are met for closed loop, the o2 plays a role in injector cycle time to get to your target afr. alsdjkfl bla, goota run,.

jacobnbr1
10-06-2008, 09:55 PM
I ran one today with the intake air restricted.

As far as the data on the machine it did what i thought it would do.

As far as the driveability it sucked.
The car was very slugish and didn't want to respond to accel off idle.

Perhaps i taped off too much intake air but in values it didn't change all that much.

I need more time to think about this...

Here is a read about the MAF>

2002 chev astro 4.3 engine

Mass Air Flow (MAF) Sensor





The Mass Air Flow (MAF) sensor measures the amount of air entering the engine. The VCM uses this information to determine the operating condition of the engine in order to control the fuel delivery. A large quantity of air indicates an acceleration. A small quantity of air indicates a deceleration or an idle.

The scan tool reads the MAF value and displays the MAF value in grams per second (gm/Sec) . At idle, the MAF value should read between 5 gm/sec - 7 gm/sec on a fully warmed up engine. The values should change rather quickly on acceleration, but values should remain fairly stable at any given RPM. When the VCM detects a malfunction in the MAF sensor circuit, the following DTCs will set:


DTC P0101 System Performance
DTC P0102 Frequency low
DTC P0103 Frequency High





And LTFT=

RANGE (0-255 COUNTS): The Long Term Fuel Trim (FT) is derived from the Short Term FT value. The VCM uses the Long Term FT for the long term correction of the fuel delivery. A value of 128 counts indicates that the fuel delivery requires no compensation to maintain a 14.7:1 air to fuel ratio. A value below 128 counts means that the fuel system is too rich and the fuel delivery is being reduced, requiring decreased injector pulse width. A value above 128 counts indicates that a lean condition exists. The VCM compensates by adding fuel, increasing the injectors pulse width.

RANGE (PERCENTAGE OF COMPENSATION REQUIRED): The Long Term FT is derived from the Short Term FT value. The VCM uses the Long Term FT for the long term correction of the fuel delivery. A value of 128 counts indicates that the fuel delivery requires no compensation to maintain a 14.7:1 air to fuel ratio. A value below 128 counts means that the fuel system is too rich and the fuel delivery is being reduced, requiring decreased injector pulse width. A value above 128 counts indicates that a lean condition exists. The VCM compensates by adding fuel, requiring increased injector pulse width. As fuel compensation is required, the difference between commanded Long Term FT and 128 counts will be displayed as a percentage.






I hope i don't get in any trouble posting these...

jacobnbr1
10-06-2008, 10:07 PM
yeah. which has a bigger influence, MAF vs IAT

Between those two options the IAT for sure...

If say you were in one of the southern states were the ambiant temp is always hot the ECM will keep the timming lean based on this data.

However; although it may retard the timing some the KS (knock sensor) will assist the ECM on where to place this advancement/retard setting...

Here is a read on the KS

2002 chev astro 4.3 engine.


RANGE (-90 TO 90 DEGREES): The knock sensor is a piezoelectric device which detects vibration due to spark knock. The VCM monitors the knock sensor signal while it performs spark advance calculations. This allows the engine to operate at maximum spark advance without spark knock to improve driveability and fuel economy. This parameter is the number of degrees.

hg2
10-06-2008, 11:51 PM
Jacobnbr1
Does any of your training include stand alone systems? I can't find much info on these and have wondered if the application of this type system would allow me to eliminate map enhancer and o2 efie along with all other mods for mpg gains with hho.From what I know and have read these computers allow for total control over fuel and ignition systems.If you have any links or docs for these systems and how they work that would be helpful.

jacobnbr1
10-07-2008, 08:55 AM
Jacobnbr1
Does any of your training include stand alone systems? I can't find much info on these and have wondered if the application of this type system would allow me to eliminate map enhancer and o2 efie along with all other mods for mpg gains with hho.From what I know and have read these computers allow for total control over fuel and ignition systems.If you have any links or docs for these systems and how they work that would be helpful.

Not sure i follow you on the "Stand Alone Systems" can you elaborate further...

hg2
10-07-2008, 09:33 AM
Not sure i follow you on the "Stand Alone Systems" can you elaborate further...

I'll try but my knowledge is limited.Looking for different ways to control afr ratios I found on several sites selling stand alone computers used mainly in high performance applications.These units are used to bypass pcm control and give the user control over functions such as fuel air ratios and timing.Most of these units are high priced more so than say superchips tunners that only have about a 10% control ability,such as(and I think this is what they call it)their mileage miser unit.Sorry I'm not very well versed in this type technology and this is the best explanation I can offer.

scirockett
10-07-2008, 10:31 AM
Originally Posted by resago
yeah. which has a bigger influence, MAF vs IAT

Between those two options the IAT for sure...

Not sure I'm onboard with that. Usually primary lookup tables are MAP vs. RPM or MAF vs. RPM and IAT is then factored in.

Stand alone replaces your factory ECU and gives you control of the timing and fuel maps, weight of other sensors like cts and iat, etc. etc. however; without understanding exactly what X amount of HHO does to say an o2 sensor reading, it would be impossible to tune.

here are my issues:

Do we understand what HHO does to the A/F mixure and/or EGT's? We need to understand this in order to tune to it.

Second, how do we expect any computer to compensate for varying amounts of HHO in the A/F mixture? Ie, there's X unmetered amount of HHO at 2000RPM and X unmetered amount of HHO at 5000 RPM. How can we program to that 1) not knowing the effects of HHO on the sensors, 2) not knowing the exact amount of HHO thats going in, and 3) knowing the percentage of HHO in the A/F mixtures will vary throughout the RPM band, which actually provides the least mixture of HHO when under load. Hope nobody thinks I'm obnoxious, because these are serious questions.. Isn't anyone concerned there is no metering of HHO? That's the name of the game in engine management - closely metering everything.. but unfortunately here, our X factor (HHO) is unmetered so everyone will get different results and our data will mean nothing. as negative as this may sound over the internet, I'm optimistic and just bringing up a point that any HHO critic would have a field day with...

resago
10-07-2008, 10:35 AM
in a previous thread, I suggested the use on an RPM switch to activate efies. Also I agree we do need a way to measure the hho and have that be a factor used by efies.

If we are talking standalone ECUs, then we would have to come up with our own maps. we could use our observed LPM and factor that into the values.
we would need to know at what concentration that fuel and timing can be adjusted vs RPM.

hg2
10-07-2008, 11:18 AM
Originally Posted by resago
yeah. which has a bigger influence, MAF vs IAT

Between those two options the IAT for sure...

Not sure I'm onboard with that. Usually primary lookup tables are MAP vs. RPM or MAF vs. RPM and IAT is then factored in.

Stand alone replaces your factory ECU and gives you control of the timing and fuel maps, weight of other sensors like cts and iat, etc. etc. however; without understanding exactly what X amount of HHO does to say an o2 sensor reading, it would be impossible to tune.

here are my issues:

Do we understand what HHO does to the A/F mixure and/or EGT's? We need to understand this in order to tune to it.

Second, how do we expect any computer to compensate for varying amounts of HHO in the A/F mixture? Ie, there's X unmetered amount of HHO at 2000RPM and X unmetered amount of HHO at 5000 RPM. How can we program to that 1) not knowing the effects of HHO on the sensors, 2) not knowing the exact amount of HHO thats going in, and 3) knowing the percentage of HHO in the A/F mixtures will vary throughout the RPM band, which actually provides the least mixture of HHO when under load. Hope nobody thinks I'm obnoxious, because these are serious questions.. Isn't anyone concerned there is no metering of HHO? That's the name of the game in engine management - closely metering everything.. but unfortunately here, our X factor (HHO) is unmetered so everyone will get different results and our data will mean nothing. as negative as this may sound over the internet, I'm optimistic and just bringing up a point that any HHO critic would have a field day with...


I think that monitoring the cylinder and exahaust gas temp. is more important than how much hho is being used.Extreme overleaning could result in catastrophic engine failure.It's said when using a stand alone,a monitoring meter such as the ones sold on sumit racing site,is a must when using one.They have bulit in alarms to alert you to problems that may occur before you do damage.This is just my humble opinion and what I've read and it's possible it could be incorrect.

resago
10-07-2008, 11:27 AM
no, you're right. we really should be using an EGT.

hg2
10-07-2008, 11:34 AM
in a previous thread, I suggested the use on an RPM switch to activate efies. Also I agree we do need a way to measure the hho and have that be a factor used by efies.

If we are talking standalone ECUs, then we would have to come up with our own maps. we could use our observed LPM and factor that into the values.
we would need to know at what concentration that fuel and timing can be adjusted vs RPM.

I've seen in a few pdfs where the idea of metering hho by use of the tps.Have you seen anything similar to this method?

scirockett
10-07-2008, 11:44 AM
monitoring chamber temp and EGT's is important, and metering your HHO into the A/F mixture along with timing controls this. yes we need to monitor this, but if we don't meter it, we have no forumla to fix anything because we don't know what's there..

now, high EGT's should not be an issue at all because we're going for a lean mixture. high EGT's are caused by rich mixtures and/or timing retard that doesn't burn all the mixture and dumps it out the exhaust.

cyl temp is what we're concerned about, and it doesn't take that lean of a mixture to start burning valves, especially under load. These temps are NOT reflected in coolant temp as one might hope.. Coolant temp is regulated by the thermostat and can be perfectly normal while your engine is cooking.. This is why anything but an o2 mod seriously scares me.. but so long as your monitor your spark gap (use COPPER plugs so you can tell..), you can keep an eye on your burn conditions.

off the top of my head:
12/13:1 mixture: a MUST for boost
14.6:1 - stoik, generally the target A/F mixture for N/A under load.
16/17:1 - lean highway cruise mixture.

A 0-5v wideband will produce these number realtime.

EGT's and cyl temps are not generally managed by the ECU. If there's a problem here, there is a problem with the tune.. well, I may be a little behind here, but SA's i've worked with do not monitor this, and I just use analog gauges. thinking outloud, I'm not sure how an ECU would accomodate for this because it's the tune that caused the problem.. bla. need to look into this. My buddy just setup Motec, so I'll hit him out (i can't afford that crap.... : )

oh, back to that chiptuners 10% thing, not sure where that number came from but the ECU's i'm familar with, the chip tuner has 100% full control of the maps and sensor weights.. I know with newer vehicles, you may have 10% control thru the OBD2 port (vag-com for VW's).

scirockett
10-07-2008, 11:53 AM
I've seen in a few pdfs where the idea of metering hho by use of the tps.Have you seen anything similar to this method?

Bingo!! now we're talkin..

I'm building a twin charged system and using a DBW (drive by wire) TB for my bypass valve..

For a standard TB with TPS, we could use that 0-5v feedback to determine where the TB is, but control would need to be external.. fail.

for the DBW TB, we can use an I/O that support duty cycle from our standalone ( I have one with Wintec II) to control this..

The next issue becomes, how do we slow down our HHO production.

taking two steps back, we need to deterime what the ideal HHO to A/F mixture is.. hmm.

Love the Meyers concept of production on demand. could it really be as simple as modulating power to the cell?

It makes sense that our target is highway cruising. I seriously doubt current production methods will produce enough to augment WOT pulls, but 99% of the time we're just cruising at 70 or so mph, where our engines are happy with leaner conditions and HHO should be advantagous.. again, an o2 sensor mod with factory management should work perfect here if we 1) understand the effect of HHO, and 2) provide consistent mixtures under these light load conditions.

kick ass.!!

scirockett
10-07-2008, 11:54 AM
not sure if I said it, but extreme overleaning will show LOW EGT's.. the heat / mixture never makes it out of the engine.

hg2
10-07-2008, 11:57 AM
oh, back to that chiptuners 10% thing, not sure where that number came from but the ECU's i'm familar with, the chip tuner has 100% full control of the maps and sensor weights.. I know with newer vehicles, you may have 10% control thru the OBD2 port (vag-com for VW's).


The 10% is the number that tech support at superchips stated as to how much leaning control the unit is capable of.Did I misunderstand the info that they gave me or can you tell me how much real control these units offer?I'm still in the dark about a lot of this and would very much like to hear your opinion on the use of these tuners and and how much they can accually control mpg gains.

scirockett
10-07-2008, 12:17 PM
ah - maybe they mean they'll only lean it out by 10%?
lkasdjklfsd
just looked it up - appears they do their tuning thru the vehicles OBD2 port. It's basically a code reader with the ability to change the tune within factory set values. So there's the 10%.. interesting the factory 'acknowledges' that a 10% leaner mixture is safe.. wonder if this applies to the entire RPM band, or just in closed loop.. hmmm. . anyone?

this is not re-chipping the vehicle, but rather giving you the ability to talk to your vehicles computer. Damn nice to have!!

the chip tuning I was referring to swaps out/modifies the factory chip/tune and replaces it with whatever you want. usually it's to match changes to the motor such as cams, more boost, larger injectors, etc.

for us cheap asses out there, I've used freeware OBD2 software with a cobbed together OBD2 port-serial interface to read codes. plans to build this are all over the internet. otherwise, it's ~$100.

hg2
10-07-2008, 12:30 PM
ah - maybe they mean they'll only lean it out by 10%?
lkasdjklfsd
just looked it up - appears they do their tuning thru the vehicles OBD2 port. It's basically a code reader with the ability to change the tune within factory set values. So there's the 10%.. interesting the factory 'acknowledges' that a 10% leaner mixture is safe.. wonder if this applies to the entire RPM band, or just in closed loop.. hmmm. . anyone?

this is not re-chipping the vehicle, but rather giving you the ability to talk to your vehicles computer. Damn nice to have!!

the chip tuning I was referring to swaps out/modifies the factory chip/tune and replaces it with whatever you want. usually it's to match changes to the motor such as cams, more boost, larger injectors, etc.

for us cheap asses out there, I've used freeware OBD2 software with a cobbed together OBD2 port-serial interface to read codes. plans to build this are all over the internet. otherwise, it's ~$100.

Yeah 10-4 on the cheapazzz I'm one of them lol.I asked what kind of mileage improvement I'd get with their mileage miser and the best they could give me was 1-4 mpg increase and for $350,to me wasn't a bargain.

Jaxom
10-07-2008, 01:15 PM
Anyone with any tuning experience will tell you that the off-the-shelf chips are basically turds. 9 times out of ten, they just use the factory calibration with minor timing and fueling changes. The 10% number they gave was probably the max. amount that they will deviate from the factory calibration. I have a lot of experience with this from modding my IROC-Z (and yes I tune it myself, in real-time through my laptop.) True tuning allows you full control over the fuel and spark curves, modifiers for things like engine temp and highway mode operation, and even self-diagnostics. It's possible to change DTC parameters so that you can tell the computer how far to let a sensor go before setting a code, or to set the idle speed at 2400rpm if you so desire. The learning curve for this stuff is incredibly steep, and in my epxerience most people who fool around with it only do that: fool around. Very few have the patience and the background to really learn and master engine management. Scirockett, you seem to be on the upper end of this learning curve. What kind of tuning background do you have? Maybe we can learn a few things from each other, and figure some stuff out.

In the grand scheme of things, PCM control will be the most effective way to utilize HHO. Setting up the hardware to put the computer in control of the HHO is simple: just use a pulse-width modulated output from the PCM to drive a solenoid valve between the intake and the HHO generator. This will let the PCM meter HHO flow by controlling how far the valve opens. A simple pressure sensor and PWM controller can then run the generator so that the HHO supply is adequate for demands, but does not build up excessively. The software side of it is the hard part, as code would have to be written from scratch for the PCM to know what to DO with the HHO. Tables and modifiers and calculations would have to be devised and a logarithm written to calculate the HHO valve duty cycle for any given engine condition.....and all that comes after figuring out when and how much HHO needs to be delivered to the engine.

As it stands now, I believe that a proportional delivery of HHO into the engine that varies with load conditions will greatly increase the gains people are seeing. The simple "X lpm all the time" delivery in use now is extremely inefficient. We can all agree that more engine airflow will need more HHO to see equal gains. That means we need more HHO at high RPM that at idle, and more under heavy load than when coasting down a hill. Right now we either have too much at idle, or not enough under load, or both.

I have a duty cycle controller prototype built that will modulate the current supplied to the generator based on a 0-5v input. I intend to use the MAP sensor to power my electrolyzer proportional to engine load, with high hopes of increasing the effectiveness of HHO. If it works, a pulse-counting circuit could be used to proportion the genny current to engine RPM. The next step after that would be a dual-input controller which accounts for both RPM and load. I just need to finish getting the system installed in my truck and we'll see what happens. This is all on a bone-stock Grand Cherokee with 245,000 miles on it, so if it works for me it should work for just about anyone else.

hg2
10-07-2008, 02:38 PM
Jaxom thanks for taking the time to write such an informative post.That answered all my questions about stand alone system,tuners and then some.I've only been here less than a week and think I can safely say you must be a huge asset to other members like myself with limited knowledge of ecm and sensor technology.Thanks and I'm looking forward to future posts about the new project you mentioned,and with your experiece I'm sure it'll be successful.

scirockett
10-07-2008, 03:04 PM
yeah!!! we're really getting somewhere!! that's great dude from what I gathered skimming it. on boosted motors, you can generally measure load by map alone. but with NA, map reaches atmosphere at part throttle so we need data from the tps as well. I gotta run, but will dump more thoughts later tonight.

Jaxom
10-07-2008, 05:22 PM
Exactly...MAP alone will not suffice under heavy loads. With a non-boosted engine, heavy throttle means atmospheric pressure (or close to it) in the intake. The throttle blades are no longer a restriction at all (if they were it would create a partial vacuum in the intake) so throttle position is not really a factor. When other restrictions are minimal, airflow is determined by RPM, displacement, and volumetric efficiency. Displacement and VE are based on the engine's mechanical design, so RPM is the only one of these that really varies. Thusly RPM becomes the best indicator of airflow during low-vacuum conditions (hence the dual MAP/RPM control I'm shooting for.)

In my experience, TPS is better used for transient conditions like sudden acceleration, as it's the first sensor reading that changes when you move your foot. With a more complex controller which actually regulates HHO flow, it would be a vital input.



HG2....Thanks for the kind words. I try to help whenever I can, in the hopes that others will do the same when I need it. So far it's been working out well on this forum, almost everybody seems to do their best to help each other.

Boltazar
10-07-2008, 07:59 PM
Jaxom thanks for taking the time to write such an informative post.That answered all my questions about stand alone system,tuners and then some.I've only been here less than a week and think I can safely say you must be a huge asset to other members like myself with limited knowledge of ecm and sensor technology.Thanks and I'm looking forward to future posts about the new project you mentioned,and with your experiece I'm sure it'll be successful.


Ditto, I could not have said it better. Thanks Hg2 and thanks Jaxom. The thought of using a laptop to tune my truck with hho truly intregues me

jacobnbr1
10-07-2008, 08:48 PM
Anyone with any tuning experience will tell you that the off-the-shelf chips are basically turds. 9 times out of ten, they just use the factory calibration with minor timing and fueling changes. The 10% number they gave was probably the max. amount that they will deviate from the factory calibration. I have a lot of experience with this from modding my IROC-Z (and yes I tune it myself, in real-time through my laptop.) True tuning allows you full control over the fuel and spark curves, modifiers for things like engine temp and highway mode operation, and even self-diagnostics. It's possible to change DTC parameters so that you can tell the computer how far to let a sensor go before setting a code, or to set the idle speed at 2400rpm if you so desire. The learning curve for this stuff is incredibly steep, and in my epxerience most people who fool around with it only do that: fool around. Very few have the patience and the background to really learn and master engine management. Scirockett, you seem to be on the upper end of this learning curve. What kind of tuning background do you have? Maybe we can learn a few things from each other, and figure some stuff out.

In the grand scheme of things, PCM control will be the most effective way to utilize HHO. Setting up the hardware to put the computer in control of the HHO is simple: just use a pulse-width modulated output from the PCM to drive a solenoid valve between the intake and the HHO generator. This will let the PCM meter HHO flow by controlling how far the valve opens. A simple pressure sensor and PWM controller can then run the generator so that the HHO supply is adequate for demands, but does not build up excessively. The software side of it is the hard part, as code would have to be written from scratch for the PCM to know what to DO with the HHO. Tables and modifiers and calculations would have to be devised and a logarithm written to calculate the HHO valve duty cycle for any given engine condition.....and all that comes after figuring out when and how much HHO needs to be delivered to the engine.

As it stands now, I believe that a proportional delivery of HHO into the engine that varies with load conditions will greatly increase the gains people are seeing. The simple "X lpm all the time" delivery in use now is extremely inefficient. We can all agree that more engine airflow will need more HHO to see equal gains. That means we need more HHO at high RPM that at idle, and more under heavy load than when coasting down a hill. Right now we either have too much at idle, or not enough under load, or both.

I have a duty cycle controller prototype built that will modulate the current supplied to the generator based on a 0-5v input. I intend to use the MAP sensor to power my electrolyzer proportional to engine load, with high hopes of increasing the effectiveness of HHO. If it works, a pulse-counting circuit could be used to proportion the genny current to engine RPM. The next step after that would be a dual-input controller which accounts for both RPM and load. I just need to finish getting the system installed in my truck and we'll see what happens. This is all on a bone-stock Grand Cherokee with 245,000 miles on it, so if it works for me it should work for just about anyone else.


Um.. I don't believe i would regulate the current to the HOD gen. but regulate with valve the flow of hydrogen.

Not unless you have a HOD that generates an excessive amount of HHO.

I was thinking more on the lines of movement of the vehicle V's rpm.
HHO is not needed at idle and for the most part not even needed 0-20 mph.

Most of the mileage benefits are going to be noticed within speeds of 25-60 and there is where i would use a regulation via VSS input.

I myself would not regulate the current of the HOD but regulate the flow through the hose to the engine depending on the speed.

Calibration tune could be set within ranges of speed reflecting an rpm count depending on gear ratio.

Not saying it is a bad idea but writing code for programs is a very hard and tricky thing to do + not to mention the program and technical setbacks.

If we could get the ECM to be replaced with a laptop or desktop program then we could write programs with python or something.

You do realize the government is not going to let us get too advanced without a mob visit right?

hg2
10-07-2008, 09:23 PM
The mob guys wouldn't bother us,the Stanley Meyers worshippers over at the Over-Unity reasearch forum keep em too busy. lol haha:cool:

Jaxom
10-08-2008, 10:31 AM
My genny will put out over 5lpm brute force with a strong electrolyte, but it gets hot FAST at that production level. It has to be pulse-width modulated anyway to keep it out of thermal runaway so why not use that as a control device?

I agree that metering the flow of HHO using a valve between the genny and the engine would be the best method, but what I'm working on is much easier to implement. A flow-metering system would require some kind of reserve capacity to prevent a loss of flow on sudden transitions...that means some kind of HHO tank or canister, which we all know is not safe in an automotive environment.

jacobnbr1
10-08-2008, 10:38 AM
I'm not all that scared of the storage of hho.

The idea would be that it have limits on the storage and limited preasure.

A simple reserve tank with a rubber top that would pop off if flashback would occour would be idea.

5LPM is awsome...

Jaxom
10-08-2008, 12:42 PM
I guess if you kept it low pressure (I.E. 5psi maybe) it wouldn't be too dangerous. A pressure switch could cycle the genny on at 4psig and off at 6psig to maintain pressure, or if you want to get high-tech a 0-5v pressure sensor could control a PWM similar to the one I built.

jacobnbr1
10-08-2008, 11:54 PM
Yea 5psi would be ok...

Can't be any worse then some of the bad engineering from Chrysler that Ive seen, namely the leaky fuel rails near the coil-pack (intrepid,caravan etc..)

I was still thinking that in order to add hho to the engine one must enlist the assistance of the pcm 1st and i still think the best way to do this where the pcm will accept the hho is by first detuning the air input by restriction.

Kinda like when nascar makes a restrictor pate mandatory at some tracks to make all cars equal.

Well if the restriction of intake air is done before the MAF the PCM "SHOULD" know no different that there is more air available thus tricking the ecm into thinking the car was at a higher altitude and changing pulse width and timing in a detuned state.

The only question is- what is th pcm going to think when hho is added and will it bring the power-loss back equal?
I have sneaking suspicion that the pcm will see the 02's and try to richen the mixture back rejecting the whole idea.

I did this very test on an 02 astro 4.3 but i had standoffs on the 02's and the car ran like ****, wanted to bog and wasn't very responsive.
However the 02's were switching just fine and the pulse width came down two digits the timing remained at pcm advancement of 16.

I need to remove the standoffs and try it again.

This van is getting an average 30mpg highway and average 18mpg city according to 2 gallon fuel tests.
I ran the van out of gas and have been only dumping two gallons of fuel in per test until it runs out again.

So far Ive ran three tests and I'm getting CEL for two codes for 02 remains 150mv within a certain count Yoda Yoda Yoda ( I'm not at the shop to read the ticket) ya-know what i mean....

I may have restricted the air too much also, who knows!

Jaxom
10-09-2008, 10:39 AM
You're going to fry the fuel pump in that van testing it that way. The fuel in the tank is what keeps the pump cool...every time you run the fuel low you overheat the pump. You'd be better off filling it, then drive 100miles and fill again, using the amount of fuel consumed to determine your mileage.

jacobnbr1
10-09-2008, 10:47 AM
You're going to fry the fuel pump in that van testing it that way. The fuel in the tank is what keeps the pump cool...every time you run the fuel low you overheat the pump. You'd be better off filling it, then drive 100miles and fill again, using the amount of fuel consumed to determine your mileage.


Yes i know...

I was wanting short consistant intervals with the same amount without confusion.

the problem with top-off is you really never know exactly where...

Jaxom
10-09-2008, 12:49 PM
I just use the same pump at the same station every time I fill, and run fuel into it until the pump shuts off. My MPG calcs using this method never vary by more than .2mpg (unless I do some towing.)

candyman55
10-12-2008, 11:42 AM
Hey guys,
I have been following this thread with much interest. I have an AFR sensor calibrator and have been playing with fuel maps a little. My vehicle is a 2007 Toyota Tundra with a 5.7 liter engine.

It seems that my calibrator can adjust the fuel from very rich to very lean with no check engine lights at all. The calibrator works on manifold pressure be it positive or negitive. And is viewble in realtime on my laptop while I drive.

Tuning for the calibrator can be found here: http://www.splitsec.com/, since the program is already written to interact with the computer it could be a really good place to start.

Since most of our driving is in a very narrow RPM range, except for startup and hard acceleration I think that we would only have to use a very small part of the map. Possibly one would be able to realize the full fuel saving s of HHO and still have Maximun power when needed. (Or am I nuts?)

hg2
10-13-2008, 08:54 AM
Anyone else using the Split Second Turbotuner or know anything about them?

Keith's Garage
10-15-2008, 10:53 AM
I did a little research on the Split Second devices. I really think this is the way that we should be heading. By using the AFR calibrator, it is basically an efie. Just use it in the same way, and lean out the computer.

candyman55
10-15-2008, 07:42 PM
I agree, the main diffrence is that an EFIE is adjustable with one setting across the entire RPM range. The calibrator is adjustable with a diffrent setting for each RPM range.

This is the way it works for me:
I lean my fuel out slightly in the 500 to 1000 RPM range -- Reason: This is the range the trucks runs at startup and idleing.

Increase the setting to lean more in the 1000 to 2000 RPM range where most driving takes place and I will realize the most savings.

Decrease lean out in the 3000 to 4000 RPM Range, and then back to normal over 4000. If I am running over 4000 RPM I am not concerned with saving fuel I'm just wanting to get some where fast.

This is just an example of some the things possible, Map B on my calibrator is a timing MAP. I am not to sure what all is going on with it but sooner or later I'll get to that to.

Mindcrime13
11-02-2008, 08:30 PM
there is a device called the predator made by diablospot, is a hanheld tuner, that let you modify the computer, by adjustimg, all the computer control things, there also another one called XCal 2 made by sct , both are great,

Keith's Garage
11-03-2008, 01:53 PM
The predator is a decent programmer. The problem is it only works with some domestic OBD2 vehicles. Plus, it really does not allow for much custom tuning. You can use Diablo's tuning software with the Predator, but you should be an experienced tuner if you are going to try this method.