Landtank MAF surprising scangauge results

[LC80Ducati996]

There is a book titled how to tune and modify engine management systems. I highly recommend it.

The FPR has a reference port to the manifold pressure on virtually every EFI system. It is there to simply keep the difference in pressure between fuel in the fuel rail and the air in the intake manifold the same. This makes for one less variable when tuning an internal combustion engine which has enough variables already.

If you look at higher flow MAFs for mustangs for example. They are calibrated for a given flow of air. Most manufacturers make a few different sizes. Using the all out racing one on all cars would not yeild as accurate a reading at idle and part throttle as sizing it for the customers power level no more no less. Think of it as like screen resolution.

It is refered to as sensor resolution by the electronic engineering types. Another interesting thing to note is that as the sensors airflow increases the injector size they recommend goes up. More air does mean more fuel but there is more to it than that. At idle and part throttle cruise a modified engines air intake is not that much different than stock as compared to the difference when either version of the engine is making full power. So just changing injectors will result in a super rich condition at idle. Remember how I said making the MAF much larger and or less restricted can result in a lower sensor output at low rpm or part throttle? Well guess how they get the idle right well a big part of it anyway. You guessed it! The engine thinks less air is going in so the injectors are triggered to spend less time open on their pulses therby compensating for the larger injectors.

Here are my recomendations for what to do for increasing performance. Tune it. You could put every engine mod imaginable in place or just a few. No matter which one of these situatons is at hand accurate tuning will always be needed to get them to their potential.


Get the newer type MAF sensor if it does not have it already.
Get E-manage, USB programing kit and maybe the ignition tuning kit if you want to take it that far.
Get a wided band 02 sensor.

I might be running the E-manage system on my turbo build instead of AEM EMS since keeping all the non engine bells and wistles running (ABS, Electronic trans etc) is easy with a piggy back tuner. It is all possible with the AEM but I would have to figure a ton of things out on my own. They do it with AEM for the supra but I doubt their engineering team will make a plug and play system for the cruiser any time soon. Reading up on them I have realized this is much better than the piggyback EMS systems of yesterday.

 

[Brian894X4]

Would it be helpeful if I took each of these sensors and hooked them up to a car engine intake, like a CRX that could draw in enough air to actually cause some readings and compare voltage readings of each sensor? I'll do this if it would provide any value to the discussion. I'll have to figure out which wires on each sensor to hook to power and then measure the voltage off of.

 

[landtank]

Evaluation was being done through my laptop using autoenginuity.

As far as the the LTFT% outside idle with the hose installed, they were near identical. But while driving the the truck they do fluctuate so there was some difference. But to the best of my ability they were very close with the exception of idle. Idle was the only place that there was a significant difference and one the vacuum hose was removed it corrected it self and fell into line with the rest.

How I determined saturation was by monitoring the air flow value. On a stock truck the MAF on my truck would read up to 23lbs of air. On 1 turbo'd truck and 2 SC'd trucks the air flow reading would go to about 26lbs and then not move even as the rpms were increasing and the O2 sensors would drop out and report 0.

With my MAF installed the air flow would continue to increase in value to as much as 36lbs of air on Turbocruiser's truck and the O2 sensors never dropped out and continued to report an acceptable AFR.

I'm not sure what to call the condition the ECU was in with the stock MAF installed but I'm assuming it's something similar to limp mode since for all practical purposes the MAF is broken.

On the trucks with wideband sensors the AFR during that time when the stock MAF was not reading any increase was much improved on with my MAF installed.

I personally think that the trigger for closed and open loop is injector duty cycle. Mainly because calculated load is not that exact. If you look at the FT% at sea level verses High altitude you will see a good bit of difference. That is because the MAF sensor and IAT sensors are not exact enough to properly calculate lbs of air which is what calculated load is derived from. This goes for either MAF.

The voltage at idle from the MAF is around .1v and fluctuating slightly. Measuring a difference with a digital VOM that I have in my opinion would be a waste of time. I did however watch the airflow numbers and still it was hard to see a difference from the fluctuating values.

There is no need to flow bench the two MAFs as I can tell you they won't be the same. By now I would have thought everyone had got that.

I hope everyone appreciates the fact that I'm basically providing everyone with about 60 hours of my time staring at the laptop. And what most companies would consider intellectual property and a very closely guarded commodity. Like my development threads I don't mind sharing it but I would appreciate some level of respect and consideration.

As far as the vendor thing, I've tried my best to offer generic help when asked and only get specific when asked. I've already had the MAF thread deleted and will have the merchandise ones and well as the rest if that is what people want. It would suck for me as I like doing them but it's not like I own this forum, I'm a guest.

 

[Brian894X4]

Putting aside the disconnected FPR thing for just a second. One question seems to surround a question of any differences with the larger intake volume of the less restrictive AFM meter housing, if I understand correctedly and how this might supposedly cause unmetered air to enter the system that the system was not expected with the old AFM.

If that's correct, then I'm wonder what the difference would be between a larger and less restrictive AFM houses verses a modified intake system in front of the AFM. For example a K&N open air filter system or a snorkle, where more airflow might be present than the engine was expecting.

Is the theory of unmetered air really a concern given those scenarios? And is so is there really any unmetered air that is entering the system? Or maybe I'm misunderstanding that particular question.

 

[landtank]

The whole purpose of the O2 feed back circuit is to compensate for miss metered air. The MAF sensor and IAT sensor provide data for the ECU to make a best guess on how much air is entering the system. That feedback circuit then compensates for the error in that guess. Toyota allows up to a 20% error on either side of ideal before that best guess is determined to be out of range.

When I was done on my truck the difference between the two housings was maybe 1 percentage point. But that was with an old original MAF so it could have been more.

In my opinion Toyota has put in plenty of safe guards and operating perameters and my MAF assembly meets them all. No one with a clean functioning sensor who has properly installed has gotten a CEL to my knowledge.

I personally would be more worried about dirty injectors as these can fool the feedback circuit and run a cylinder lean.

 

[jamisobe]

By removing the vacuum line the fuel rail pressure is not reduced and this increases the pressure differential. This increase in differential means that at any given pulse the injectors will deliver more fuel. Since my MAF at idle already calculates a lower base injector timing this works to its favor. The lower calculated base timing is offset by the higher pressure differential. And if designed properly it will deliver the same amount of fuel as the stock setup will.

It is my opinion that it is this higher pressure differential that is responsible for eliminating the idle stumble that people are seeing. I believe that the higher pressure differential is producing a better and more consistent spray from the injectors which is eliminating the stumble.

This post is just my understanding as to what is happening and in no way should be taken as absolute gospel on this subject and is only meant as an aid to understanding how I designed my MAF and intended on to work.

FWIW, Thanks again to you and your cohorts for investing the time and energy into doing this. I realize that I am somewhat of a simpleton, but I trust the piles of data you all produced, I enjoyed following the design thread, and I enjoy the significant gains in performance. It is a fantastic, practical mod that works flawlessly as presented. Woe to those who miss out if you were to actually discontinue.

 

[96r50]

if i were rick looking at this kind of thread i would seriously reconsider going through the hassle of any other innovations for this kind of response.

I hope not, because I want to buy a turbo system from him whenever it comes to fruition. I sincerely hope that Rick continues doing what he is doing, creating specific-need products to improve on some of the shortcomings of the mighty 80 series cruisers!

I wanted to chime in for a moment and say thanks for all the good dialogue. I have never understood the fuel management system on our 80's, heck i still don't, but this thread is helping me to better understand how it works. So a big thanks to all those participating.

Xeleventy-three. I've learned a ton from this thread alone!

for someone like Rick, a carefully worded waiver could be viable. subject to local state consumer protection laws, it will at least partially protect him from being sued by the person who bought the product from him. it won't protect him from third parties, but third parties are unlikely to have a viable claim against him since, if the product fails, it is very unlikely to lead to any injury other than to the vehicle itself.

that said, my point was that it is a shame we are even talking about such matters.

First off, it sucks that this is an issue at all. Realistically speaking, If he felt it was a concern, couldn't Rick create a simple business (using Beo's Wing Nut with Garage idea!), incorporate it and sell his products through there? Would that not at least ensure that Rick personally cannot be sued? (Obviously I am not a lawyer/banker/accountant/plumber/business person. I just like trucks)

 

[Brian894X4]

Wow that link to the Toyota information papers is an absolute wealth of information.

A few things that I found pretty relevent to this discussion in the OBD II section. With regards to the fuel pressure regulator. One of the tests they offer to find out if the ECM is working correctly in closed loop operation is removing the fuel pressure regulator vac line, noting that (as mentioned here before) that the computer has the ability to compensate approximately 20% either way.

As they put it, removing the line artificially causes a rich condition which the computer can then temporarily compensate for. However, they caution that leaving the line removed for very long may push the computer beyond it's limit to compensate and caused a long term rich condition, which can cause other issues.

It also notes that "major A/F imbalances" can be caused among other things, by a leaky fuel pressure regulator.

It doesn't look like anyone with this mod are having any issues, but the thing that bothers me is Toyota is pretty specific about having it's fuel pressure lowered under certain conditions and not having one range of pressure, rather two ranges. But they don't go into detail as to why this is important.

I would think a constant pressure system would be simplier. Maybe one reason for the lower pressure at idle and lower speeds could be to relieve the ECU from having to make major adjustments. Many engines spend a significant amount of time idling or at low rpm, so if you lower the fuel pressure during those times and the ECU is expecting that, you don't have to make a major compensation based on other sensors.

One of the questions I have is that if the rig does go into limp mode due to sensor failures, with higher fuel pressure than it's expecting, would that cause a major overrich condition, if the vehicle is expecting a lower fuel pressure at idle and low rpm. I don't know how much LTFT would override the computer's base map in an open loop, limp mode situation. But I wonder if this could be a potential problem if 02 sensors failed or multiple sensors failed.

Has anyone come up with a specific reason as to why the new sensor won’t accurate meter the air at idle? If it’s in the development threat, I guess that gone, so I can’t check. Is it because the ECM is not expecting good readings at low rpm and bases it’s idle qualities on other sensors and now the new sensor is throwing the ECM off with it’s accurate readings at low rpm? This is the part that confuses me the most.

The sensor “appears” to read accurate throughout the rpm range, but not at idle. Why would this be?

I've also noticed that at cold start up with this sensor, engine rpms are slightly lower than before and there's a slight stumble. Maybe because the sensor calibration is really confusing the ECM at idle? I don’t know.

That all said, I can see why one would assume if the engine runs just fine and there's no code being thrown then there shouldn't be a problem. Toyota seems to have a pretty good feedback system set up and any major problems should show up one way or another. Noone has complained of a rough running or poorly run engine. So the bottom line concerns are is it possible that the conditions could be just off enough to cause long term damage? Who knows. But to me, more importantly, will some extreme condition, overwhelm the abilty of the ECM to compensate, if in fact the sensor really is not quite calibrated properly to the ECM. The extreme conditions I thinking of are extreme altitude, extreme temps and major sensor failure, such as 02 sensor failure or multiple sensor failure. And then finally is there is any problems with running a constant fuel pressure in a system designed for two pressure ranges.

If there was just another way to get this sensor to work in perfect harmony with the ECM at idle so the computer wouldn't have to be tricked by removing the FPR line, this mod would be a no brainer.

 

[LC80Ducati996]

The whole purpose of the OEM O2 feedback is to adjust for things that change. One big area it helps is adjusting for differences in fuel. Depending on age engines run differently a new motor, a just broken in one and a high milage one will all have different fuel trms.

 

[SeanAndHis80]

Man - you guys should spend a few hours on a Supra board. They push some of the Mk4s to 1300HP. They regularly obliterate the entire Toyota management system. They regularly put way more pressure on the fuel rail. They regularly swap MAFs or eliminate them altogether. They drop in larger injectors. Remove EGR, all kinds of stuff that would send some people into rants of "Mr T don't do that" around here.

The wideband sensor is the main indicator of safe engine management to them. Yeah the members do seem to blow their engines up more - but it is usually to do with too much boost, rarely on an engine under 350RWHP.

On a side note - the dyno is more than happy to run my truck with the front driveshaft removed. I am asking about their gas analysis abilities now.

 

[Romer]

I have had the MAF in my SC truck for two years with no issues and 1 year in Sarah's stock truck with no issues. I would do it again in a minute. A large portion of my club has done this mod and not one person has had anything bad to say about it. Believe me, if one of my club mates was unhappy, they would have said so.

The majority of this technical discussion has been great.

I have done a lot of mods to my truck and know each one is my liability, I break it it's my fault. Even simple mods like changing the fluid in the Fan and running a 4runner blade. Mod's like taking my Australian Heat Exchanger and installing it in my Coolant lines. Mod's like all the additional fuse block and extra outlets I am running. I do understand Christo's comment about protecting Rick, but that doesn't have any technical relevance to the actual product.

Rick is a curious fellow and he has gone off to try and make his truck better. He shares that with others and so what if he sells them.

Being an engineer and having designed a few high tech things myself, I understand Rick's sense of ownership and his frustration at the tone of part of this thread. Yet open technical discussion is important for "enlightenment"

It is what it is, Buy it, admire it or ignore it.

Disclaimer- These represent the opinions of the user Romer and not the moderator

 

[turbocruiser]

I have had the MAF in my SC truck for two years with no issues and 1 year in Sarah's stock truck with no issues. I would do it again in a minute. A large portion of my club has done this mod and not one person has had anything bad to say about it. Believe me, if one of my club mates was unhappy, they would have said so.

The majority of this technical discussion has been great.

I have done a lot of mods to my truck and know each one is my liability, I break it it's my fault. Even simple mods like changing the fluid in the Fan and running a 4runner blade. Mod's like taking my Australian Heat Exchanger and installing it in my Coolant lines. Mod's like all the additional fuse block and extra outlets I am running. I do understand Christo's comment about protecting Rick, but that doesn't have any technical relevance to the actual product.

Rick is a curious fellow and he has gone off to try and make his truck better. He shares that with others and so what if he sells them.

Being an engineer and having designed a few high tech things myself, I understand Rick's sense of ownership and his frustration at the tone of part of this thread. Yet open technical discussion is important for "enlightenment"

It is what it is, Buy it, admire it or ignore it.

Disclaimer- These represent the opinions of the user Romer and not the moderator

Very well worded! I can't believe the twists this thread has taken ... talk about taking "What If's" to the extreme! When "we" (I say "we" cause I simply helped send data Rick's way all along with Christo's advice by the way) developed this thing it was exhaustive examination of everything from butt dyno, to computer error codes to all the OBD-II readings to wideband readings etc. All along we SLOWLY ratcheted up the load and SLOWLY ratcheted up the performance making sure all along that nothing from the ECU's own codes to the wideband readings were off. The only thing Christo advised, very wisely so, is that we not run this thing without a wideband. There were no real concerns about calibration being off at that time! There were no real concerns about capping off the FPR at that time! There were thoughts of these things but no real concerns because the wideband works to reveal the end result. And, as always, being the expert that Christo is I took his advice as literally as possible and had him install the wideband for me before I put my foot to the floor. Now almost two years later the thing still works as well as ever. I'm still getting better economy, better performance and better readings from all the data sources we started with. Ohh yea, I'm still also getting 36 frickin pounds of air through the thing with an AFR that gets "as lean as" 10.8 after flooring the thing to totally insane speeds up steep grades. With my stock MAF I never measured more than 26 pounds of air and my AF gauge stops showing readings richer than 10.0 so it could have been 10.0 or even richer and virtually every sensor reading was right at "0" in other words they were all useless to the ECU. One of the "What If's" has always been "what if the ECU doesn't know what to do with this data?" Well the answer is, I think, it loves the extra data and it responds well to the extra data. If not why are all my sensors still reading relevant numbers, why is my AFR better, why is my performance better, why is my economy better?

I think that it is a serious shame that Rick has removed his threads on this. I'd encourage him to restore them.

And I still say Christo's super sweet front bumper absolutely sucks when it is installed upside down!!!

That's All.

 

[turbocruiser]

That's All.

Wait, that's not all, ...

one other thing that I don't think was mentioned much here (I might have missed it somewhere in this thread) is to keep in mind the very admirable fact that although Christo was willing to help me do something I seriously wanted to do with my rig (ie. install the LT MAF), the context of that occasion was my rig being 100% clear of anyone's liability or warranty with parts or labor or anything. He very clearly told me the risks, how to avoid the risks with a wideband and then told me he'd happily do the work to install the wideband. In other words as a customer I told Christo I wanted to install the LT MAF and he helped me do it and do it as correctly and mindfully as possible. Talk about superb customer service.

Now, in the context of this occasion when he indeed has significant liability with whatever is covered on the Super Charger install, Christo is still offering superb customer service by making absolutely sure everything that he does is done according to the installation instructions! Again, talk about superb customer service.

Additionally, for the benefit of the people who have the LT MAF without a wideband he's sorta telling you the same things he told me two years ago and that sort of advice is what we all appreciate from him. Somehow this particular modification is more controversial than others ,I really don't know why, and somehow this particular thread feels more personal than others, again I really don't know why.

But let's all remember and admire that both Christo and Rick are just "doing their thing here" and perhaps let's pay more attention to the fact that in both my situation and in his current customer's situation Christo was offering superb customer service. Okay, that's really all!

 

[sleeoffroad]

How I determined saturation was by monitoring the air flow value. On a stock truck the MAF on my truck would read up to 23lbs of air. On 1 turbo'd truck and 2 SC'd trucks the air flow reading would go to about 26lbs and then not move even as the rpms were increasing and the O2 sensors would drop out and report 0.

With my MAF installed the air flow would continue to increase in value to as much as 36lbs of air on Turbocruiser's truck and the O2 sensors never dropped out and continued to report an acceptable AFR.

My point is that the values you are looking at is a calculated value from a voltage reading. The calculation assumes a certain response and bore size of MAF housing. If you change either, the calculation does not know this. So you can not compare the values. Without knowing that 3 volt from your sensor means 20 lbs (or whatever), you can not use the airflow numbers as shows on the OBD2 interface. Making any interpretation from those values are not correct. They might be, by pure luck, but that is what needs to be verified.

I'm not sure what to call the condition the ECU was in with the stock MAF installed but I'm assuming it's something similar to limp mode since for all practical purposes the MAF is broken.

that might well be since a boosted truck is exceeding the suspected parameters of the MAF as designed by Toyota for a normally aspirated motor.

On the trucks with wideband sensors the AFR during that time when the stock MAF was not reading any increase was much improved on with my MAF installed.

Yes, you are seeing this effect, but just because it has a postive effect does not mean the sensor choice is right or calibrated. Again you are not considering the increase in manifold pressure that causes the injectors to inject less fuel for the duty cycle as asked by the ECU.

I personally think that the trigger for closed and open loop is injector duty cycle. Mainly because calculated load is not that exact. If you look at the FT% at sea level verses High altitude you will see a good bit of difference. That is because the MAF sensor and IAT sensors are not exact enough to properly calculate lbs of air which is what calculated load is derived from. This goes for either MAF.

It is not the injector cycle that triggers open or closed loop. Have a look at this document. It lists what is used http://www.autoshop101.com/forms/h48.pdf

The voltage at idle from the MAF is around .1v and fluctuating slightly. Measuring a difference with a digital VOM that I have in my opinion would be a waste of time. I did however watch the airflow numbers and still it was hard to see a difference from the fluctuating values.

I think it would be worthwhile to plot voltages at RPM intervals for both sensors and compare.

There is no need to flow bench the two MAFs as I can tell you they won't be the same. By now I would have thought everyone had got that.

I do think there is a need to actually know what you are sending to the ECU. You can simply not send incorrect info to the ECU and expect that the feedback to correct. If that is what is happening, then this is not any better than those guys selling some resistors in a black box on ebay that leans out trucks and they claim massive hp and mileage increases.

I am not saying that a different response curve, ie linear vs logarithmic or an extended one for boosted truck is a bad thing, but you have to be sure that if the ECU sees 25lbs of air flow as measured and calculated from the MAF, it is actually 25lbs. You housing allows for more flow due to design and less restriction, then it would be great to know that a measured 33 lbs of airlow is actually reported as such to the computer.

I hope everyone appreciates the fact that I'm basically providing everyone with about 60 hours of my time staring at the laptop. And what most companies would consider intellectual property and a very closely guarded commodity. Like my development threads I don't mind sharing it but I would appreciate some level of respect and consideration.

I think people do, and strange as it might seem, I am actually trying to help you. Have you ever looked at what these people do?
Abaco Performance, LLC

As far as the vendor thing, I've tried my best to offer generic help when asked and only get specific when asked. I've already had the MAF thread deleted and will have the merchandise ones and well as the rest if that is what people want. It would suck for me as I like doing them but it's not like I own this forum, I'm a guest.

I don't think the development thread should be deleted. Neither the merchandise threads. We are all guests, and if you profit from your efforts, then that is good if that is what you choose to do.

I think the value in this development and your intent to do a boosted truck without piggy back fuel management is admirable and would be great if it works.

 

[sleeoffroad]

Is the theory of unmetered air really a concern given those scenarios? And is so is there really any unmetered air that is entering the system? Or maybe I'm misunderstanding that particular question.

Sorry, I called it unmetered air and that might have lead to confusion. Incorrectly measured air due to uncalibrated sensor and housing might be more accurate.

In the case of a KN, no air filter or whatever before the MAF does not matter. If the stock MAF used (the one the ECU progamming was done for) then 3v from the sensor means the same thing, does not mattter what is in from of it.

If you have a vacuum leak AFTER the MAF (like the intake tube cracking), then air is entering the system that did not go past the MAF and then things are out of balance. MAF measured 20 lbs or air, but another 5 lbs of air is sucked in after the MAF. So 25lbs of real air is entering the truck, but it gives fuel for 20lbs. So it runs lean and the feedbacks will try and increase it. That is the same effect as 25lbs of air entering the MAF (uncalibrated) but being reported at 20lbs.

 

[sleeoffroad]

The only thing Christo advised, very wisely so, is that we not run this thing without a wideband. There were no real concerns about calibration being off at that time! There were no real concerns about capping off the FPR at that time!

I expressed my concerns about sensor calibration then as well. I expressed them in several conversations I had with people when they asked me what I thought. One of them was Hants from our club. He might recall that after a Rising sun meeting. Since you guys were still testing etc at that point, I did not care to get into it.

As for the FPR line disconnect, I am not sure at what point that happened, or if you had it disconnected when we did the wideband on your truck. I looked at your logs. At that point I also advised you that the O2 sensors do not go off-line. I mentioned that you need to check with Autoenginuity to see if they can display the Close loop/ Open loop flag and correlate with the 0 values you were seeing.

There were thoughts of these things but no real concerns because the wideband works to reveal the end result. And, as always, being the expert that Christo is I took his advice as literally as possible and had him install the wideband for me before I put my foot to the floor. Now almost two years later the thing still works as well as ever. I'm still getting better economy, better performance and better readings from all the data sources we started with. Ohh yea, I'm still also getting 36 frickin pounds of air through the thing with an AFR that gets "as lean as" 10.8 after flooring the thing to totally insane speeds up steep grades.

You think you are flowing 36 lbs of air, you have no way of knowing that. So using that as information is wrong. Your ECU thinks it is 36lbs and reports it as such, but there is not an ounce of evidence that it is a correct number. Look at the link I posted for Rick and see what those people to to calibrate MAF sensors.

With my stock MAF I never measured more than 26 pounds of air and my AF gauge stops showing readings richer than 10.0 so it could have been 10.0 or even richer and virtually every sensor reading was right at "0" in other words they were all useless to the ECU. One of the "What If's" has always been "what if the ECU doesn't know what to do with this data?" Well the answer is, I think, it loves the extra data and it responds well to the extra data. If not why are all my sensors still reading relevant numbers, why is my AFR better, why is my performance better, why is my economy better?

You are running leaner. You are under boost. Your injectors have to overcome the boost in the plenum and injects less fluid since you don't have a reference on your FPR anymore. That is fact. What part is the MAF playing in this?

The nice thing for you is that it is a good thing for your truck, but that does not mean it is right and under adverse conditions you can not have a catastrophic failure. Sure big what if, but you guys are interpreting bogus data.

Did you ever try and run your truck with the FPR disconnected with the original MAF to see if the same thing will happen?

I think that it is a serious shame that Rick has removed his threads on this. I'd encourage him to restore them.

[/quote]
So do I.

And I still say Christo's super sweet front bumper absolutely sucks when it is installed upside down!!!

That's All.

that be true.

 

[sleeoffroad]

Here are my recomendations for what to do for increasing performance. Tune it. You could put every engine mod imaginable in place or just a few. No matter which one of these situatons is at hand accurate tuning will always be needed to get them to their potential.


Get the newer type MAF sensor if it does not have it already.
Get E-manage, USB programing kit and maybe the ignition tuning kit if you want to take it that far.
Get a wided band 02 sensor.

I might be running the E-manage system on my turbo build instead of AEM EMS since keeping all the non engine bells and wistles running (ABS, Electronic trans etc) is easy with a piggy back tuner. It is all possible with the AEM but I would have to figure a ton of things out on my own. They do it with AEM for the supra but I doubt their engineering team will make a plug and play system for the cruiser any time soon. Reading up on them I have realized this is much better than the piggyback EMS systems of yesterday.

I do understand your point on this, but Rick wants to do a turbo without adding external fuel management. That is what started all this.

 

[sleeoffroad]

Being an engineer and having designed a few high tech things myself, I understand Rick's sense of ownership and his frustration at the tone of part of this thread. Yet open technical discussion is important for "enlightenment"

Being and engineer, I assume you also know that if you make conclusions from results, you want to be sure those results you rely on is accurate.

 

[sleeoffroad]

The whole purpose of the OEM O2 feedback is to adjust for things that change. One big area it helps is adjusting for differences in fuel. Depending on age engines run differently a new motor, a just broken in one and a high milage one will all have different fuel trms.

Yes, here is a good read on it. http://www.autoshop101.com/forms/h37.pdf

It is important for people to know that O2 sensors does NOT read air fuel ratio. They only read oxygen in the exhaust gasses. No other gas. That is why it does not know about high NOx or any of the other gasses. It is also not very sensitive. If you read the above you will see that the 02 sensor is termed a switch for LEAN or RICH (ie, below or above 14.7). It does not know a little bit rich, or a little bit lean. Or more lean or how lean the truck is running.


That is why wide band O2's are recommended when you really start playing.

As for turbocruiser, thanks for the kind words, but just a point I want to make. We advised the wide band because we did not know anything about the calibration of the sensor. We did not ignore it at that time.

 

[LC80Ducati996]

The Abaco sensor looks like the ticket to run in blow thru on my build. I could convert to speed density but a mass airflow system has some advantages. The Mass Airflow is better at part throttle and other areas. If you tune a MAF and a SD system I think they are pretty much equal at WOT so on a drag car I would not use a MAF but a speed density system.