[sleeoffroad]

Originally Posted by aclos3

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]

Originally Posted by sleeoffroad

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]

Originally Posted by aclos3

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]

Originally Posted by landtank

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]

Originally Posted by 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.

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]

Originally Posted by sleeoffroad

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]

Originally Posted by turbocruiser

...
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]

Originally Posted by 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.

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]

Originally Posted by sleeoffroad

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

IMO, Bulls##t

Originally Posted by sleeoffroad

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.

Originally Posted by sleeoffroad

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]

Originally Posted by Cattledog

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.

[firetruck41]

Who's gonna be the first to go Megasquirt? No More worrying about how Mr. Toyota made things work.

[Riad]

Originally Posted by firetruck41

Who's gonna be the first to go Megasquirt? No More worrying about how Mr. Toyota made things work.

won't you need injectors with 6 holes for that ?

[alaskacruiser]

Originally Posted by aclos3

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.
[...]
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.

Assumption #1: assumed new MAF sensor is "reading true more often" and provides less "noisy" data than the original MAF without referring to data that shows increased accuracy. Please provide reference that shows an example of noisy vs. less noisy analog output from original vs. new MAF and point out the "noise" you are referring to.

Originally Posted by aclos3

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.
[...]
The ECU does not have to be "changed" to take advantage of a cleaner signal from one of its sensors.
[...]
The software adapts to this and a computer can indeed create "more numbers" or perhaps more accurately a better data curve from a cleaner signal.

Assumption #2: assumed that the new MAF sensor is providing data that is significantly different from original sensor in resolution and range after A/D conversion and reading of data by ECU. (The data provided by the new sensor is only relevant to us after A/D conversion and processing by the ECU, not before that). The ECU programming and bit resolution on the A/D are likely matched precisely to the sensitivity and range of the analog sensor (original MAF). The questions I think Christo is asking are related to this:

a) Limitations in the ECU programming (how it responds to small input changes) or quantization error in the A/D conversion could render any additional resolution provided by the new sensor meaningless after A/D conversion and processing by the ECU.

b) Hardcoded limits in ECU programming (might be programmed to only handle data within a certain range) or a limited-range A/D (one that maxes out before the higher max. output of the new MAF) could render any increase in range provided by the new sensor meaningless.

Please provide reference that indicates these things are not happening.

Originally Posted by aclos3

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.

Assumption #3: assumed code in ECU has programming to filter out "noisy" input from original MAF. Please provide reference that shows ECU handling of "noisy" data and how this noise is defined.

[Brian894X4]

I think there are a lot of legitimate questions here, but I don't want to turn this into an attackfest on Landtank and his mod. First of all, a lot of work clearly went into it and second of all, at least some of these issues were probably covered in other threads. So, I can understand if he and others who participated in the development of this mod are getting frustrated with having to answer the same questions over and over again.

I'm not an armchair speculator of this product. I'm an actual customer and it's on my truck right now. That means whatever the outcome of this discussion is will have a direct affect on my vehicle. So, I'm hoping to flush out a few issues and get a few questions answered without chasing away the one person who can help answer them the best, the original developer of this mod.

If getting a my emissions checked out will go a significant distance in answering some of these questions, I will gladly figure out a way to get my emissions check out, even if I have to pay someone to do it. Any other suggestions would be greatly appreciated.

On a slightly seperate, but related note, check out the 70 series 1FZ-FE thread again....

http://forum.ih8mud.com/70-series-te...questions.html

There's some new interesting information. Apparently, the Venzualian 80 series, which continued production through 2007, used the same "old version" of the 1FZ-FE right up to 2007. There's a picture of it and you can see the same intake, apparently MAF, and even EGR and other features as our engines, all of which are changed on the 70 series version of the 1FZ starting sometime after 1998.

[landtank]

Christo has made up his mind that I'm wrong about how this MAF works and how the fueling system on our truck works. There is nothing more to be said to him about this. Repeating myself another 100 times is not going to change anything and only lead to more disagreement.

I've stated numerous times that if you plug in the vacuum line from the FPR that the LTFT% will shift about 18% and not to do it. I've even stated it here earlier on.

So what does he do, he plugs in the FPR and has an issue with the fact that the LTFT% is way out of whack at idle.

He now what's answers to his questions as in his mind this is evidence that there is a problem with the MAF sensor. He knows full well what my answer is but refuses to accept it.

The basic problem here is that he refuses to accept the idea that he may be wrong about how the 80 fueling system works. He is not ready to question his own understanding and ready to consider another opinion.

I didn't read some tech manual or discuss this with some trained technicians I reversed engineered it. To understand what that means, I did a series of tests and evaluations on the system to determined there effect on how the ECU managed them.

The first and biggest assumption he has made is that the vacuum line is there to maintain a constant pressure differential. I don't know where he got this idea but I can tell you with great certainty that this is not the case.

I could go into detail how me and Cattledog determined this but it's more clear to just say that on a boosted truck with a stock MAF sensor at WOT the engine is running crazy rich. He already knows this and posted it up way back years ago and showed this to everyone on a dyno chart he has.

So if Toyota designed the system to need a constant pressure differential why is it running so rich? If anything you want less fuel and a drop in fuel rail pressure is needed.

What Christo needs to do is accept the idea that I might be right, install the unit as instructed and then get out of his chair and actually eval the piece for himself. This way at least he can ask some pertinent questions. And if he is sincere about wanting to sell these then he needs to do this anyway to validate the product.

But I'm sure I'll come back here with a line edited reply from him telling me why I'm wrong and how he knows better.

And that is why I've not been engaging with him on this thread and a few others. There is no point to it and only leads to the demise of a thread.

[NLXTACY]

I know enough to not care how it works and appreciate the huge amounts effort put forth to make this product. I bought it, installed it, used it, love it. It changed the shift pattern on my truck, especially at WOT. I definitely have more power, perceived or not, and I have been getting very very slight mpg improvements. Look its slight. Less then .5mpg buts it consistent and its there. Questioning the product at this point with SOO many successes seems completely counter productive. To be honest, as an outsider of this development it very much seems that there is more of a personal conflict going on that perhaps not everyone is aware of. I could be wrong but that is how this thread reads to me.

[Brian894X4]

Rick,

I have a few quick questions. Not challenges. Just questions. Unfortunately, please understand, I'm pretty ignorant on the fuel system managment and yes some of these questions are spurred on by some of what Christo said, but also from my own research.

1) Is is possible that Toyota intentionally wanted the engine to run rich to prevent detonation and other issues during certain conditions, such as extreme hot weather, desert running, etc?

2) Is is possible that Toyota wanted a very high rich condition with the TRD supercharger at WOT for those same reasons?

3) Do you have any idea why Toyota kept the FPR in place on the 1FZ-FE during the production years 1998-2008 when the 1995-1997 sensor was no longer being used? I would assume that Toyota had figured out a better way to regulate the fuel pressure at idle, but it would appear not? Although it should be noted that Toyota did not use this mod sensor for the 1FZ-FE ever, so maybe whatever it did use (hot wire temp sensor and maybe a MAP sensor) wasn't accurate enough?

4) Do other Toyota vehicles that use the same sensor we are using for this mod also have a FPR hooked up and if so, why do you think that is the case?

5) Do you think if I were get sniff emissions tested that it might provide any valuable information towards this modification?

Thanks.

[LC80Ducati996]

There is absolutely no need for mr T or anyone to get all elaborate with fuel pressure.

The actual fine tuning of the AFR is and should be accomplished via the ecu's injector pulse width outputs.

The manifold referenced FPR is SOP on nearly all EFI engines. It keeps the pressure differential constant. Lets forget about MAF changes for a secod and look at the effect of the reference port.

If you dont have the line hooked up then there is a higher pressure differential between the fuel in the rail and the vacuum in the intake. So it actually richens up idle.

Now if a larger MAF reads less airflow at idle then this would compensate for that.

For all I know the maf housing could flow well and have a good resolution from idle to the amount of air most need at full power.

However the proper way to do this is to use a programmable ECU or a chip you can tune yourself to recalibrate the ECU for the response curve of the MAF and other engine mods.

[jamisobe]

I have been using Rick's MAF for a while now and I can definitely feel an improvement in performance. My mileage went down a little though I suspect that is due to both my now heavier tires and my now heavier foot. I have a history of freely exercising the motor winding it out as high as 5.4K. The shifts have become very nice.

I have never seen any codes. No hiccups. No hints of any problems. If there were issues with the fuel rail pressure the wideband 02 sensor would realistically detect at least a hint of such a problem. Nobody has posted any facts that would suggest that the missing vacuum would or does cause detriment. Saying that the vacuum must be improtant because Mr T put it there doesn't fly with me. Its hearsay and without proof to the contrary I think it is safe to shelve the concern until someone actually can show a hint of lean operation. I suppose that a few of us could check a spark plug to see if there are any signs of a deformed electrode or a widened gap, but based on Rick's extensive research I am confident that the appearance of such damage is highly unlikely.

With 210K miles I am due to PM the HG so I will be taking advantage of the opportunity to build a performance head for atop of my bomb proof bottom end (cam, valve, and port work ). When I pull the head off here in the near future (I should have about 5K miles with Rick's MAF) I will be sure to check for burned exhaust valves. I don't expect there will be any.

Enjoy this well designed and extensively tested modification. It really is a beautiful advancement that functions flawlessly. Oh, and here is a side by side for those that have not had the opportunity to see all of the air...


Not only is the pod huge, but you can see the how the stock housing narrows close to the counter.

The intake of the stock MAF will literally fit inside the intake of the redesigned MAF.

[Lugboot]

I would guarantee the ECUs in the newer trucks with the newer engines are programmed differently. There's been a ton of advances since 1996. Heck, look, Ma, no more MAF! It isn't the same ECU with the same code.

How many of these trucks with Rick's MAF have gotten OBD inspections? OBD inspection failpoints are stricter than ASM tailpipe inspection failpoints. How much of a lean condition is a bad thing? Codes are set and the MIL is set to illuminate when conditions exist that would likely cause the emissions of an average vehicle to exceed the emissions standards by 1.5 times. So, in this case, if the emissions standards for NOx is "Y", then the MIL would come on when conditions exist that drive the NOx emissions to Y x 1.5.

Is running the engine consistently at Y x 1.4, for example, a long term bad thing? Running leaner and hotter and producing more NOx at a level just under the radar of OBD for tens of thousands of miles--any impact on the engine? I think this is Christo's question.

There's a lot of variables here, to be sure. I'm not picking sides, either, btw, just trying to add a little more info.