Landtank MAF surprising scangauge results
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I noticed in the earlier pages of this thread, both you and Turbocruiser had the FPR line pulled and capped (posts from 01-09). You now both have it running to the manifold. Any specific reason for that change? Why? When? Results? To my concerns voiced over a year ago, what did you discover that caused you to change your mind on the 'recommended' hook-up?
I'm looking for correction of the technical information I posted - your thoughts on me aside. A lot of 'engineer-types' on this list, many arguing with Christo over pretty basic stuff. - IMO. I put popcorn because even reading the same documentation, conclusions seem to carry this premise: The 80 is different. The ecu is the same, so is the software - and so is a given MAF derived Load Calculations. Insert: Change MAF.
Let me know when you are able to post the relevant LTMAF voltage slopes.
It appears a lot of folks are either reading this thread for the popcorn, or maybe some would like to actually understand how the ecu and MAF mods work. I'm up for the latter as the Toyota documentation appears pretty clear, and observe and acknowledge the former seems to be the focus?
Cheers
Scott J
94 FZJ80 Supercharged
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this is why i believe he is just a random computer locked in some room with some moderate artificial intelligence
Zabaware - Web Hal - Chat with a computer onlineafter this i must be on his or its ignore list if im not already
Sumo
I have said repeatedly that Christo brought forth real data and everyone appreciated it. You have brought forth nothing. Don't for one GD Minute take it that because I looked at Christo's data and tried something different as any kind of validation of your BS
You continually state your awesome experiance, yet you never answer simple questions as to where. Then say stupid things like you said above "I smile at the charge" You continually dismiss points others make with a lot of VERIFIABLE experiance. You continue to ask people to prove to you, why should they prove to you? What an ass you are
I have said repeatedly that Christo brought forth real data and everyone appreciated it. You have brought forth nothing. Don't for one GD Minute take it that because I looked at Christo's data and tried something different as any kind of validation of your BS
You continually state your awesome experiance, yet you never answer simple questions as to where. Then say stupid things like you said above "I smile at the charge" You continually dismiss points others make with a lot of VERIFIABLE experiance. You continue to ask people to prove to you, why should they prove to you? What an ass you are
This isn't about me, and IMO, a moderator should set the example to not make it so. Verifiable experience with what? Christo's data is the same series of articles I am using to reference. And I reference many of Christo's posts too. And way prior to Christo's involvement in this thread, I presented the Pressure Differential issue with a MAF mod. And in August of 2007 - wrote several PM's directly to TC and *you* to hook that manifold reference line back up. Now done? Ok, and....?
Proof? Of what? The MAF slopes have changed with a modded MAF. These changes change the Load Values, which include the Timing Values! Where is that otherwise verified, addressed, or measured?
Anyone is welcome to jump off this discussion. It's not about me, it's about how a MAF works, stock vs modded. You can opinion that I don't understand it. If so, then correct the detailed information I presented, not selectively punting who did.
Thanks for your consideration
Scott J
94 FZJ80 Supercharged
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Scott.
Prove your credentials. Posting some tech training info from a non-toyota website (with Toyota's copyright on it, no less) does not make you an expert. Do you want me to post the diagrams from the EWD that describe ECU operation and show the MAF sensor using a biased wheatstone bridge with an op-amp voltage buffer biasing a BJT internally? Does that demonstrate that I am a MAF designer expert? No.
Substantiate your credential claims, or shut it.
Prove your credentials. Posting some tech training info from a non-toyota website (with Toyota's copyright on it, no less) does not make you an expert. Do you want me to post the diagrams from the EWD that describe ECU operation and show the MAF sensor using a biased wheatstone bridge with an op-amp voltage buffer biasing a BJT internally? Does that demonstrate that I am a MAF designer expert? No.
Substantiate your credential claims, or shut it.
Have you ever walked by a street protest and seen two idiots from each side screaming at each other? Any protest - pro-life/pro-choice, dem/repub, war/anti - it doesn't matter. They will just scream at each other in the insane belief that if they yell louder and longer that they will somehow convince the other side of the error of their ways. No listening, no respect for differing opinions or values, no open minds. Apparently, it doesn't even take two parties to do this. The end result is just noise, not any form of productive discourse (regardless of what the parties may say).
And now this thread is just noise. It doesn't matter one bit who is right (if anybody) because the thread can no longer be reasonable used. It has turned into noise. One big, stinky, steamy pile of . . .noise.
(And my apologies as this just adds to it)
And now this thread is just noise. It doesn't matter one bit who is right (if anybody) because the thread can no longer be reasonable used. It has turned into noise. One big, stinky, steamy pile of . . .noise.
(And my apologies as this just adds to it)
Actually, I think I should since it's relevant. Hopefully, as rick points out, what will be salvaged from this thread is Scott's acceptance of the fact that his misinformation is at best a detriment to the threads he posts in and at worse dangerous for others. Maybe people will learn that or maybe Scott will change his ways.
So on that note, let's analyze one of Scott's critical claims.
Observe (my emphasis added)
Now I submit, for Toyota's own wiring diagrams and service info specifically for this truck:
(and I quote)
Also of note, in Toyota's docs for acceptable ranges for sensor inputs and resistance the MAF readings (well, except IAT) are conspicuously missing:
So on that note, let's analyze one of Scott's critical claims.
Observe (my emphasis added)
Now I submit, for Toyota's own wiring diagrams and service info specifically for this truck:
(and I quote)
Also of note, in Toyota's docs for acceptable ranges for sensor inputs and resistance the MAF readings (well, except IAT) are conspicuously missing:
Well, that probably has more to do with the fact that the MAF will run 0-5 volts anyway so the acceptable range is essentially fixed, and the engineers most likely never expected anyone to screw with it in the first place.
There are plenty of specs that Mr. T (and other companies) don't provide that tuners regularly play with.
it's absolutely is about you.
Where's the part 4 of the ABC series where you are going to computer control two cooling fans to intentionally elevate the engines temperature to the saturation point to achieve high efficiency, better fuel mileage all the time lower the mechanical wear on the components? You were so looking forward to my review of the final product you were giddy.
I'll tell you, NO WHERE! While it might have worked out for you on paper in reality it was a bust and you just walked away not to bring it up again.
So instead of getting some lime light on the forum by actually making a positive contribution you get it by tearing down others who have.
And that's not talking about me either.
How about the CDL use at speed question where you went on a rant about the pin 7 mod being dangerous if it wasn't done when installing a CDL switch. That circuit has the complexity of a spring loaded mouse trap and you where completely baffled by it. Days of you arguing and insulting people.
You really need to be shown the door!
I would agree except the R-values for the wheatstone bridge would be an effective test point and they provide values for the TPS, etc. One could make the same case that the TPS should always fall within a certain range of values, so why list that spec?
Toyota provides these specs primarily for diagnostics and repair, not for tuners to mess with. Toyota does list R-values for THA-E2 resistance in the RM, but for the voltage test they simply specify "Blow air into the MAF meter, and check that the voltage fluctuates." Now yes, there is something to be said for the fact that Toyota cannot expect the average mechanic to have access to equipment that can provide constant velocity/temperature laminar flow at a controlled rate to get specific voltages... but there is also something to be said for the ~1kohm range (2k-3k acceptable) that accounts for a ~20% drift off center spec of 2.5k.
I'd love to get access to our SAE lab and see if I can put a set of MAFs through their paces on our equipment. I'll send some emails but I don't expect much.
Or the endless nonsense about ABS in low traction situations and how independent 4 wheel brake control is useless
The best I can do is to install both MAFs in tandem on my engine and compare voltage output between the two while running the engine.
Everything is on it's way but it will likely be a week before I can get to it.
And I fully expect another round of new attaxcks if I'm able to sync the signals between the two MAFs.
Normally to compare/compile MAF voltage slopes, a load bearing dyno is used with specific rpms and specific throttle angles. Change MAF, same rpms, same dyno load, and same throttle angles. IME plotting voltage values this way, it takes a several seconds to get a steady MAF voltage after each change of rpm/TPS. Concurrent/tandem MAF's will introduce voltage slope error into the readings of both.
With regard to NG's EWD references, there are no voltage slopes for the MAF, because it is assumed to be good if it doesn't throw a code, and produces 'a' voltage with uncalibrated airflow thru it. As Ebag333 proposes, as known good, the MAF value is assumed to follow exactly the voltage slope, sampling rate and resolution programmed into the software (because the ecu software can't learn a MAF has changed, and the engine it's attached to hasn't changed). LTFT is retained in memory on engine shut-down, but the MAF calculated Timing Values and Load Values are not stored on engine shut-down.
I'm sorry you feel attacked Rick, I thought I presented how 0-5v MAF works, in general, modded, and specific to the 80. The MAF voltage slopes stock v modded will present objective data regarding what's happening with this mod.
Cheers
Scott J
94 FZJ80 Supercharged
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Trying to stay strictly technical here (as opposed to personal) ... I went back and looked through run after run after run of our data logs and driving logs ... contrary to the conclusions presented about "Load" and how off it obviously will be btwn the two MAFs, there was actually no apparent change to load btwn the two MAFs! I was able to find dozens and dozens of lines of data btwn the two MAFs with the same load, same rpm, same throttle position percentage, etc. Dozens upon dozens of lines of data where airflow was higher but Load was not higher or lower. Now granted I did not spend time trying to find lines of data where Load was different, with everything else equal (it really blurs my blurry eyes looking through all that data), but I was able to find line after line after line with specific settings equal btwn the two MAFs as well as Load.
So, just to address several specific things presented throughout the posts above.
1. Load seems similar at all ranges of operation.
2. Of course the percentage range is the same 0% - 99% load.
3. Of course the voltage range is the same 0 - 5v.
4. The two graphical representations revealing voltage slopes and such might be modestly "off", or, they might be absolutely "on" ... that we cannot conclude from what I've written. But with so many set points perfectly matching, I don't think they are off as much as some would want us to think.
Feel free to discuss/dismiss this along with all the other data offered so far (data logs, driving logs, emissions tests, wideband readings, etc). Thanks.
So, just to address several specific things presented throughout the posts above.
1. Load seems similar at all ranges of operation.
2. Of course the percentage range is the same 0% - 99% load.
3. Of course the voltage range is the same 0 - 5v.
4. The two graphical representations revealing voltage slopes and such might be modestly "off", or, they might be absolutely "on" ... that we cannot conclude from what I've written. But with so many set points perfectly matching, I don't think they are off as much as some would want us to think.
Feel free to discuss/dismiss this along with all the other data offered so far (data logs, driving logs, emissions tests, wideband readings, etc). Thanks.
It's certainly possible voltage slopes can intersect at points - and even be 'similar' in profile in portions of it's slope. It could also be that the OBDII reader is not capable of giving the raw data required. A fixed 'engine' load for MAF Voltage Slopes is usually done on a load bearing dyno, with various tip-in throttle angles. I suggest a turbo/SC running at altitude will yield different Load Values from OBDII than a stock truck. All good things to test, but the baseline comparative MAF voltages from a bone stock truck is the first data to cull.
TC, are you currently running the LTMAF or the Stock MAF with the FPR hooked up? I noticed as of April '09, you had changed back to the stock MAF. Is this when both you and Romer hooked the FPR reference line to the intake manifold?
https://forum.ih8mud.com/80-series-...-vs-intake-manifold-pressure-here-skinny.html
Is the current agreement then, that the FPR reference line should be hooked up to the modded MAF? That isn't clear.
Cheers
Scott J
94 FZJ80 Supercharged
I see the goal posts are moving as fast as the information comes in!
What agreement are you talking about?
Sumotoy, has it ever crossed your mind that the embedded pcb in the MAF sensor is more than a pass through for the raw sensor data?
It's not uncommon for manufacturers to delegate precessing loads to individual sensors taking the load off the main controller.
In our case the sensor itself would yield a matched linear signal to the air flow so the ECU would not have to do any calculations and a single program could be used on multiple platforms with minor tweaks.
Now before you go all Sumo on the idea, take a little time to understand what I just wrote and how such a strategy could make this a little easier when dealing with a multitude of very similar systems that were slightly different.
It's not uncommon for manufacturers to delegate precessing loads to individual sensors taking the load off the main controller.
In our case the sensor itself would yield a matched linear signal to the air flow so the ECU would not have to do any calculations and a single program could be used on multiple platforms with minor tweaks.
Now before you go all Sumo on the idea, take a little time to understand what I just wrote and how such a strategy could make this a little easier when dealing with a multitude of very similar systems that were slightly different.
I'm open to your explanations of MAF operation if you have the voltage slopes of the two sensors to back it up. To the given software in the 80 ecu, you have the problem that the software tuning of the stock MAF includes obstructions to flow designed to increase low speed flow across the stock sensor. That's not a pcb function, that's a design parameter that is dictated in the software voltage slope function. A pick-nit, MAF voltage slopes are not linear.
I have measured voltage slopes on the exact same MAF sensor insert used for a late model v6 N/A motor and a twin turbo version of a late model v6 motor (identical-interchangeable part number). In the former, the 4.85 max voltage is 214g/s and in the latter, the 4.85 max voltage is over 300g/s. That's software programming of MAF voltage slope to the engine air demand. I can site several examples in a variety of vehicle applications and modded MAF apps where this is the case. Do you have any experience with MAF scaling or MAF transfer functions in stock or standalone MAF based ecu's? Are you claiming MAF scaling in the 80 software is different (generic) somehow? How so? Are you claiming that you can manipulate the pcb function of the LTMAF to mimic the stock 80 MAF and software? I predict that will be a tough accomplishment given the software. I encourage you to start with the stock and modded voltage slopes, you present a tough argument to support.
Since you fully represent this LTMAF mod, after reading Christo's measures of the FPR operation you had incorrectly presented, are you now instructing the FPR manifold vacuum reference be hooked up with the LTMAF mod? That's still not clear.
Thanks for your continued interest. Please post your comparaitve MAF voltage slopes, so this discussion can move on to actual relevant measures to the modified hardware.
Thanks
Scott J
94 FZJ80 Supercharged
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What is the Toyota part number of the MAF you tested? Since you are asking all the questions pertaining to LTs technical credentials, can you return the favor and tell us the name of your shop?
No, you can cite. And do it. Specifically, and with irrefutable and undeniable technical evidence. Not a list of vehicles you believe qualify this claim, with testable documentation that explicitly and unquestionably proves your claims either from direct observation or directly from the manufacturer. The same crap you keep demanding ad-nauseum from everyone else in this thread... back your own claims up with your own demands.
I bet $1,000 you cannot and will not do it. I defy you to prove me wrong.