Landtank MAF surprising scangauge results

[sleeoffroad]

Because it samples that analog stream at a frequency. It is easy to see why the original MAF design creates more turbulence and it is also not hard to believe that the older sensor is more sensitive to turbulence. The new MAF obviously provides more laminar flow and the new sensor is likely able provide a meaningful signal even in more turbulent air (compared to OEM).

That is purely an assumption. Do you have the response curve of the sensor compared to flow?

When the computer samples the signal from this modified sensor setup it does not have to throw out nearly as many data points as noise because the sensor is not washing out in turbulence as often.

Where did you get that information? How does it know the sensor was "washed out".

This should allow the computer to better control the engine. I can't seem to find the part where they noticed an increase in sampling frequency, so maybe I was mistaken on this point. Even if the computer does not increase sampling frequency, many more of its samples are accurate; which is better than simply an increased sample rate anyway.

That again is an assumption. If Rick has the data on that, he can post it.

I haven't heard of anyone failing an emissions sniff test or having engine problems because of this mod. I'm not sure how many of these things Landtank has sold, but I'd think that after a year and a half problems would have cropped up and been well documented on this forum.

I have not hear of anyone taking it to CO Emissions with the sensor on yet. I might be wrong as well, it might be buried in a thread somewhere.

 

[aclos3]

Would an emissions sniff test failing in the NOX range pretty much answer our questions, or could tail pipe emissions of NOX be insignificant to the test, yet still be high enough to be unsafe for the motor? I know in most states/counties that do testing, they usually don't even bother to sniff test an OBDII rig, so this still may be a dead end.

 

[turbocruiser]

Sure, but Rick posted why Toyota used the vacuum line on the FPR and it was simply incorrect. From his development thread.

All I am asking is where is the info coming from re: the accuracy and dynamic range of the sensor. I don't think that is out of line to ask from someone that sell this mod.

Agreed but I also think that Rick has answered/corrected all that in the previous three long threads.



That might simply be due to the rise in fuel pressure. Why is the sensor causing high LTFT with the Toyota designed fuel system (that is still used today) hooked up?

What harm would rising the fuel rail pressure possibly present?



The ECU has not changed. How can it result in more adjustments? The AFM is anolog. All A to D is done inside the computer.

I'm not saying the ECU changed and I'm not trying to say that the MAF or the ECU is making "more" adjustments (although what I wrote is somewhat confusing); what I am saying is that the adjustments are smaller - with the stock MAF the AFR in closed loop varied relatively widely with the LT MAF the AFR in closed loop varies much less widely. That's All.



Have you had it on a analyzer / dyno and actually verified that it is OK?

What would a wideband miss?



Yes, I can see that. But what I believe you are seeing is that in general the sensor is causing the truck to run lean accross the board. Which in your case, might be a good thing since you have extra air coming in and the stock map might be really rich on the top end.

It is running leaner in open loop (which is wonderful thing) but not in closed loop. If it was running lean in closed loop I'd be worried with it, since its not, I'm not. I guess I'm not understanding what I would miss with the wideband reading that everthing is okay? Is it possible to have good AFR's but bad NOX?



I am not a naysayer. I am simply asking questions. I have asked some in the past, but since we did not have to deal with the mod, I let it go. Now we have to deal with it and I want to see what is up.[/QUOTE]

Agreed again, you have went out of your way to say that you are not slamming this sweet thing and that you are just trying to understand it more. I wasn't referring to you there. I do however think that you out of all of us offer more opportunity to measure the fuel rail pressures, the injector capacity and injector cycles and some of the other things I wasn't able to measure through my butt, my computer or my wideband. I'd love for you to measure this and post your findings for us and as always anything you present as experience or expertise I take 100% as accurate. Again I wasn't referring to you as a naysayer, you are simply an openly admitted inquisitor.



PS. I only wrote in red because I basically haven't figured out how to have those fancy multiple quotes like you have! DOH!!!

 

[aclos3]

That is purely an assumption. Do you have the response curve of the sensor compared to flow?

An assumption, but not a stretch to believe.

Where did you get that information? How does it know the sensor was "washed out".

This is just how ECUs work. Of course, if the sensor isn't actually doing a better job then the computer wouldn't gain any benefit, but if the sensor IS reading true more often, the computer will benefit in its monitoring and therefore its controlling ability.

That again is an assumption. If Rick has the data on that, he can post it.

It only relies on the initial assumption of "improved signal from the new sensor" to be true. If a computer is seeing noise from a sensor as important as the MAF, its ability to control the engine is degraded. If that signal improves, its ability to control the engine improves -- there is no assumption about this.

I have not hear of anyone taking it to CO Emissions with the sensor on yet. I might be wrong as well, it might be buried in a thread somewhere.

Do you know if they sniff test OBDII vehicles in CO emissions? In Washington only a few of the counties emissions test at all, and on OBDII rigs, I blieve they only plug into your OBDII port.

 

[landtank]

Christo, what problems are you having with the truck that has my housing on it?

 

[e9999]

Brian, isn't there a gizmo that looks like a MAF connector on the intake manifold in that Vennie?

added: OK, I now see that Christo mentioned that also above. A pressure sensor it is then? Not quite directly a flow rate but can be related, of course.

 

[sleeoffroad]

This is just how ECUs work. Of course, if the sensor isn't actually doing a better job then the computer wouldn't gain any benefit, but if the sensor IS reading true more often, the computer will benefit in its monitoring and therefore its controlling ability.

Where do you get the information that the Toyota ECU has any way of rejecting mass air flow readings? What is true? The ECU puts out a voltage to the MAF. It uses it's analog circuit to create a voltage that is then read by the ECU. There is no intelligence in that to determine if a reading is good or bad, except if it is our of range.

It only relies on the initial assumption of "improved signal from the new sensor" to be true. If a computer is seeing noise from a sensor as important as the MAF, its ability to control the engine is degraded. If that signal improves, its ability to control the engine improves -- there is no assumption about this.

Where is the evidence of this noise? And how is noise defined?

Do you know if they sniff test OBDII vehicles in CO emissions? In Washington only a few of the counties emissions test at all, and on OBDII rigs, I blieve they only plug into your OBDII port.

They dyno run on for an average drive cycle and actually have a sniffer that measures the gasses coming out.

 

[sleeoffroad]

Christo, what problems are you having with the truck that has my housing on it?

The trouble is the LTFT at idle that is to high with the FPR connected. We are not willing to cap it on a boosted truck. That is why I started reading into what you did.

 

[sleeoffroad]

Sure, but Rick posted why Toyota used the vacuum line on the FPR and it was simply incorrect. From his development thread.

All I am asking is where is the info coming from re: the accuracy and dynamic range of the sensor. I don't think that is out of line to ask from someone that sell this mod.

Agreed but I also think that Rick has answered/corrected all that in the previous three long threads.

Sorry, I did not see any answers on the actual response of the curve as measured against actual air flow.

That might simply be due to the rise in fuel pressure. Why is the sensor causing high LTFT with the Toyota designed fuel system (that is still used today) hooked up?

What harm would rising the fuel rail pressure possibly present?

The fact that it is nor right is enough. If the air measurements are off at idle, they are most likely going to be off across the board.

The ECU has not changed. How can it result in more adjustments? The AFM is anolog. All A to D is done inside the computer.

I'm not saying the ECU changed and I'm not trying to say that the MAF or the ECU is making "more" adjustments (although what I wrote is somewhat confusing); what I am saying is that the adjustments are smaller - with the stock MAF the AFR in closed loop varied relatively widely with the LT MAF the AFR in closed loop varies much less widely. That's All.

How much of this attributed to the fact that your fuel pressure differential between the manifold and the fuel rail is dropping when you go under boost (when you have the FPR disconnected)? Same with your truck running leaner under boost.

Have you had it on a analyzer / dyno and actually verified that it is OK?

What would a wideband miss?

You can still have high combustion temperatures and not see it on the wideband. Probably not dangerously so, but it could be.

Yes, I can see that. But what I believe you are seeing is that in general the sensor is causing the truck to run lean accross the board. Which in your case, might be a good thing since you have extra air coming in and the stock map might be really rich on the top end.

It is running leaner in open loop (which is wonderful thing) but not in closed loop. If it was running lean in closed loop I'd be worried with it, since its not, I'm not. I guess I'm not understanding what I would miss with the wideband reading that everthing is okay? Is it possible to have good AFR's but bad NOX?

See my comment on fuel pressure. If the disconnect of the FPR at idle drops LTFT from 20% to 0% imagine what it would do when you have boost on the one side of the injector and still the same fuel pressure. Effective decrease on fuel pressure, thus leaner and it might have nothing to do with the sensor.

I am not a naysayer. I am simply asking questions. I have asked some in the past, but since we did not have to deal with the mod, I let it go. Now we have to deal with it and I want to see what is up.

Agreed again, you have went out of your way to say that you are not slamming this sweet thing and that you are just trying to understand it more. I wasn't referring to you there. I do however think that you out of all of us offer more opportunity to measure the fuel rail pressures, the injector capacity and injector cycles and some of the other things I wasn't able to measure through my butt, my computer or my wideband. I'd love for you to measure this and post your findings for us and as always anything you present as experience or expertise I take 100% as accurate. Again I wasn't referring to you as a naysayer, you are simply an openly admitted inquisitor.

All fine and dandy, but Rick is selling this, so I am think that the testing and info should come from him.

PS. I only wrote in red because I basically haven't figured out how to have those fancy multiple quotes like you have! DOH!!!

Manual text editing baby !

 

[landtank]

The trouble is the LTFT at idle that is to high with the FPR connected. We are not willing to cap it on a boosted truck. That is why I started reading into what you did.

Ah yes. by all means don't follow my instructions and do with it what you want.

 

[TrickyT]

...
2. AFR's in closed loop are almost the same with more "micro-adjustments" made. IOW, with the Stock MAF, AFR in closed loop averages 14.7 but it bounces between 14.3 and 15.3. With the LT MAF, AFR in closed loop averages 14.7 but it adjusts alot btwn 14.7, 14.8, 14.6, etc. It "appears" that the sensor limits the range of adjustment and makes many more "micro-adjustments" as opposed to the .4 to .8 AFR range with the Stock MAF...

Another explanation for this observation, since we know the ECU has not been modified and is therefore making the same calculations at the same rate as it was prior to the new MAF, is that the signal coming from the new MAF fluctuates less. In other words, it's less noisy. With a less noisy input signal from the MAF, one would expect less "noise" in the AFR measurements.

 

[LC80Ducati996]

The issue with MAF sensors is that larger sensors do not measure lower RPMs as accurately.

This is one of the many reasons why many performance applications get converted to speed density. The stock MAF gets pegged far below the max airflow of the engines intake but a larger MAF is not so good at idle.

I have yet to see an OEM FPR that did not have manifold absolute pressure connected to its reference port.

I have been thru this on a few vehicles. MAF mods, MAF translators etc.. When it was all said and done a programmable ECU and a wide band o2 sensor made the other attempts look like a pathetic waste of time.

If you are going to keep a forced induction build a Mass Airflow System puttng a hotwire MAF sensor in blowthru and using a programmable ECU is your best bet.

If not just get E-manage and change it to speed density.

 

[Brian894X4]

My 1995 is OBD II, but because of the year is usually sniffer tested, not plugged in. Since I have this mod, if I could get it sniffer tested, what would I be looking for? What readings? And what would it prove?

 

[Kernal]

Being a confused newb I don't want to get inbetween the major commenters above, only questions I have are:

1. are they still available and what does one cost?
2. is there any newer/better toyota MAF sensor, or updated part, that fits into the original housing, or replaces it?
3. does the "torpedo" design of the inside bits of the MAF housing serve any purpose, like protecting the sensor from debris?
4. how difficult is it to check the various emissions to see if they are off (better, worse, or no change) due to the modified MAF? (does anyone with the mod live in a state that checks the emissions?)

Ill sit back and watch.

 

[aclos3]

On my old truck and sniff testing in Washington State they'd give you a print out that showed carbon monoxide/dioxide, hydrocarbons, oxygen and NOx. If your state sniff tests NOx (I would think most would, since NOx contributes to smog), you're in luck. I would think if we were running lean enough to cause any kind of damage, we'd fail the NOx sniff test. I don't know this for sure though!

 

[aclos3]

Being a confused newb I don't want to get inbetween the major commenters above, only questions I have are:

1. are they still available and what does one cost?
2. is there any newer/better toyota MAF sensor, or updated part, that fits into the original housing, or replaces it?
3. does the "torpedo" design of the inside bits of the MAF housing serve any purpose, like protecting the sensor from debris?
4. how difficult is it to check the various emissions to see if they are off (better, worse, or no change) due to the modified MAF? (does anyone with the mod live in a state that checks the emissions?)

Ill sit back and watch.

1. Still available. Go to the Vendors Market tab and you'll find the "Landtank MAF" thread.
2. Not that I know of. This MAF housing was designed to accommodate a newer Toyota sensor, and when looking at the internals, it becomes very clear that the sensor types are vastly different.
3. The torpedo design is likely necessary for the old sensor to work properly in the way that it guides air. I doubt it is there to protect anything, if you've got debris making it to this section of the system, you've got bigger problems than breaking the sensor!
4. I have read of people smog testing this mod, but most areas just plug in OBDII vehicles and don't actually sniff the exhaust like they do on older vehicles. As long as no engine lights are showing AND you haven't just cleared your computer of codes to make the light go off, you should pass emissions. I haven't heard of cases where your computer is showing levels that cause you to fail an emissions test but NOT throw an engine code. Maybe this happens, but it's gotta be rare.

 

[aclos3]

I wonder if our emissions test facility would allow me to test even though I just got new tabs through Jan. 10. I also wonder if they'd humor me and give me a sniff test if I asked. I know I've seen a print out of NOx emissions on a Washington sniff test performed on my old truck. They're pretty by the books at these state run facilities and probably wouldn't allow this kind of exploratory testing though.

To have access to just a couple tests! I'd run it with the stock MAF and the modified one a few times and see if we're getting high NOx with the new MAF. I need to make a friend at the emission test facility.... hmm.

 

[Cattledog]

Brian, yes, I am not trying to shoot this mod down, or discredit the work Rick did.

IMO, Bulls##t

Exactly, I am not saying everyones motor is going blow up.

No you are inferring it. From my point of view you are trashing the product without data to support your position. Instead you put it on others to post the information for you to pick apart as you see fit.

However it is not something to ignore if we change one of the major input to the fuel management system and then disconnect Toyota engineered systems to get the desired results.

Are you suggesting the unichip FMU unit you are selling is the better choice in fuel managment than Rick's MAF housing with new sensor Does the unichip offer less risk?... If my memory serves me correct the unichip programing (timing and fuel) were mapped ear not the two knock sensors on the truck.... If you could hear the knock then pull the timing or add fuel...

I am not going to post data logs they are deleted off my computer. Ask Rick or Turbocruiser for the info. Bet their logs are gone too.

 

[landtank]

well, there is over a 150 trucks out there running this MAF and I have only heard of one issue and that was a visual in CA. (trickyT)

Does everyone just scan the ECU now? I have to believe some have had the sniff test.

 

[sleeoffroad]

IMO, Bulls##t

Ok, that is your viewpoint. What part about what I posted is BS? This is not a pissing match. If Rick does not want to respond to questions, then so be it. It will remain questions.

No you are inferring it. From my point of view you are trashing the product without data to support your position. Instead you put it on others to post the information for you to pick apart as you see fit.

Where did I trash the product. I am simply asking questions that I can not get answers to. What is wrong with that? What data do you want from me? I posted links to Toyota documentation when I made statements. If everyone got this defensive on this board, then nothing new would develop. Rick is a vendor in this situation. I have no desire to make or produce a MAF. He did. I am sorry if I am the only one questioning it. Everytime in the past someone asked questions, people got pissy and they people quit asking the questions.

Are you suggesting the unichip FMU unit you are selling is the better choice in fuel managment than Rick's MAF housing with new sensor Does the unichip offer less risk?... If my memory serves me correct the unichip programing (timing and fuel) were mapped ear not the two knock sensors on the truck.... If you could hear the knock then pull the timing or add fuel...

When did we ever sell a Unichip? Or ever install one? Unichips were sold by Man-a-fre as part of the Safari kit. We installed a number of kits but never used the Unchip. The early ones (not to be confused by that Unichip USA is selling now) had problems with heat and stopped working when they got hot.

I did not propose any different product or a better way to do it. Has it ever occurred to you that if we like the MAF and the answer that we got, that we might actually recommend it to customers and/or talk to Rick about selling it?

I am not going to post data logs they are deleted off my computer. Ask Rick or Turbocruiser for the info. Bet their logs are gone too.