Pre-Turbo Dual Widebands
05-13-2016, 11:12 AM
#41
Okay....now I see what your saying Stevie. I thought you were trying to say a sealed chamber, single inlet with an orifice and the O2 sensor in it....in that case pressure would always be the same as everywhere else in the system pre-turbo. But with the chamber having an OUTLET ALSO and bypassing back into the downpipe (lower pressure), you have a flow past the sensor....and pressure downstream of the orifice should be lower (depending on plumbing size and orifice size).
You would just have to size the orifice such that the O2 sensor sees a large enough sample to function properly, but not too much that you are venting a bunch of exhaust gas past the turbine (is likely very little and would impose no decrease in spool time if orifice was small enough). Also your outlet tubing off the chamber needs to be large enough that you do not increase back pressure beyond what the orifice was originally sized for.
Anyways I do not see myself plumbing all the way back to my downpipe for both banks to make this work. I would probably just vent to atmosphere and run a tiny orifice off of each...Might be a fun little project to tinker with at some point.
You would just have to size the orifice such that the O2 sensor sees a large enough sample to function properly, but not too much that you are venting a bunch of exhaust gas past the turbine (is likely very little and would impose no decrease in spool time if orifice was small enough). Also your outlet tubing off the chamber needs to be large enough that you do not increase back pressure beyond what the orifice was originally sized for.
Anyways I do not see myself plumbing all the way back to my downpipe for both banks to make this work. I would probably just vent to atmosphere and run a tiny orifice off of each...Might be a fun little project to tinker with at some point.
05-13-2016, 11:18 AM
#42
9 Second Club
The only thing about venting to atmosphere would be the sound would be irritating
But yes, you're understanding is correct.
Ultimately you do not need a lot of airflow over the sensor, it just needs some over it, but if venting to atmosphere make the discharge pipe longish so as to prevent fresh air ever hitting the sensor and skewing readings.
But you'd want the lead orifice small anyway, as it is still a pre-turbine leak.
But yes, you're understanding is correct.
Ultimately you do not need a lot of airflow over the sensor, it just needs some over it, but if venting to atmosphere make the discharge pipe longish so as to prevent fresh air ever hitting the sensor and skewing readings.
But you'd want the lead orifice small anyway, as it is still a pre-turbine leak.
05-17-2016, 10:48 AM
#43
It's the VERY BASIC principal that some dont seem to grasp, air will move from high pressure to low. And yes you're correct except it isnt reliant on vacuum as such, just the pressure differential.
Forcefed seems to think...
Exhaust manifold pressure pre w/g, ie before the control orifice is the same as the w/g discharge either to atmosphere or into the DP, which of course is nonsense.
He also seems to think in a basic boost control setup, manifold pressure is the same as that applied to the w/g chamber to blow it open after the control orifice bleeds some off.....which is also totally incorrect. If he was correct, none of our systems that vent air after a control orifice would ever allow us to alter boost over basic mechanical spring settings.
Hopefulyl he'll take a minute or more to read what he just wrote and realise how wrong he is.
Even more baffling is why he seems to think something is post turbo, when the connecting lines to the exhaust manifold...ie pre-turbo are there in all their nasty glory for those with eyes to see.
And if someone really wanted to mount them "directly" onto the hotside, they could also do this, just extend the sensor up a couple of inches from the hotside, and as you've said a small orifice to supply air to the sensor then route the larger diameter discharge back into the DP.
It's SIMPLE, SIMPLE, SIMPLE.
Forcefed seems to think...
Exhaust manifold pressure pre w/g, ie before the control orifice is the same as the w/g discharge either to atmosphere or into the DP, which of course is nonsense.
He also seems to think in a basic boost control setup, manifold pressure is the same as that applied to the w/g chamber to blow it open after the control orifice bleeds some off.....which is also totally incorrect. If he was correct, none of our systems that vent air after a control orifice would ever allow us to alter boost over basic mechanical spring settings.
Hopefulyl he'll take a minute or more to read what he just wrote and realise how wrong he is.
Even more baffling is why he seems to think something is post turbo, when the connecting lines to the exhaust manifold...ie pre-turbo are there in all their nasty glory for those with eyes to see.
And if someone really wanted to mount them "directly" onto the hotside, they could also do this, just extend the sensor up a couple of inches from the hotside, and as you've said a small orifice to supply air to the sensor then route the larger diameter discharge back into the DP.
It's SIMPLE, SIMPLE, SIMPLE.
Forcefed seems to think...
Exhaust manifold pressure pre w/g, ie before the control orifice is the same as the w/g discharge either to atmosphere or into the DP, which of course is nonsense.
Exhaust manifold pressure pre w/g, ie before the control orifice is the same as the w/g discharge either to atmosphere or into the DP, which of course is nonsense.
“They will be fine pre-turbo, just be aware they will be less reliable.”
Pre-turbo is a sealed pressure system. In a sealed pressure system, the sensor it WILL be exposed to pressure and WILL report incorrectly. Period. This is why they have the pressure differential skew maps and why some of the newer systems factor pressure into the readings. That is my only point and it is 100% correct. Because you installed a WB02 sensor pre-turbo and it produced readings, that doesn’t make those readings correct. If you were to run 2 sensors, one pre and one post turbo and compared them you’d see the difference very clearly.
No, I didn’t notice the smaller SS lines from the runner going to the 02 sensor stand pipes, my bad. This also is no way changes the fact that throwing a WB02 sensor into a runner pre-turbo produces incorrect readings, which is the point of this thread.
I can see the venting method working. Making a chamber that bleeds pressure from the pre-turbo side into the low pressure DP side is a totally different scenario/topic. You are also bleeding energy used to power the turbo with a setup like that. How large of a bleed hole is necessary to get a good read with the sensor? Even using eight 1/8th inch bleed lines off each runner similar to the setups pictured above (though the lines look larger than 1/8th"?) is the equivalent to having a 1" tube venting your turbine drive pressure to the down pipe. If there are tiny orifices/bleeds in the tubing I'd also think those would clog easily with exh soot. My 1/16th line used to measure backpressure clogged up pretty quickly with carbon, and that’s running low carbon E85 fuel.
05-17-2016, 12:15 PM
#44
9 Second Club
Boost control, exhaust, whatever. It's simple movement of air. Doesnt matter what you're using that air for, all the same principals apply. It could even be a fart ! It goes from high pressure to low.
And boost control IS 100% relevant in we use orifices of different sizes to regulate the flow or air and pressure in the system to trick the w/g into seeing less so the spring/valve remains closed for longer so we can see higher boost.
So again, exact same principals at play.
And As I've already said and you've seen it is NOT a sealed system.
And I've had a 2ft long brake pipe for my pre-turbine EGBP for a couple of years, and it has never clogged, and used same deal many times before with no problems.
That's 3/16" OD so could easily be 1/16" ID or even less.
IMO a hole that size should never be clogging in that environment.
And boost control IS 100% relevant in we use orifices of different sizes to regulate the flow or air and pressure in the system to trick the w/g into seeing less so the spring/valve remains closed for longer so we can see higher boost.
So again, exact same principals at play.
And As I've already said and you've seen it is NOT a sealed system.
And I've had a 2ft long brake pipe for my pre-turbine EGBP for a couple of years, and it has never clogged, and used same deal many times before with no problems.
That's 3/16" OD so could easily be 1/16" ID or even less.
IMO a hole that size should never be clogging in that environment.
05-17-2016, 12:36 PM
#45
Where are the high and low pressure areas pre-turbo exactly? Low pressure areas pre-turbo don’t exist, that’s the point. No matter where you tap the system pre turbo you'll get the same pressure.
None of that information changes the fact that you were dead wrong. You stated the sensor would operate normally pre turbo… It won’t. You can dance around 50 topics from farts to airflow all you want… but nothing changes that.
I’m happy your holes don’t get clogged, mine did. Super common on the diesel forums. I figured I’d be fine with ethanol, but wasn’t.
I’m not familiar with bleeding pre-turbo gas to a sensor post turbo. I don’t know how large of a supply line you’d need. If you wanted true WB02 control over every cylinder, even using a 1/16th line on every cylinder would equate to the same thing as drilling a ˝” hole in the exh manifold. Seems like a bad idea IMO… probably why we don’t see it.
None of that information changes the fact that you were dead wrong. You stated the sensor would operate normally pre turbo… It won’t. You can dance around 50 topics from farts to airflow all you want… but nothing changes that.
I’m happy your holes don’t get clogged, mine did. Super common on the diesel forums. I figured I’d be fine with ethanol, but wasn’t.
I’m not familiar with bleeding pre-turbo gas to a sensor post turbo. I don’t know how large of a supply line you’d need. If you wanted true WB02 control over every cylinder, even using a 1/16th line on every cylinder would equate to the same thing as drilling a ˝” hole in the exh manifold. Seems like a bad idea IMO… probably why we don’t see it.
05-17-2016, 12:49 PM
#46
9 Second Club
Where are the high and low pressure areas pre-turbo exactly? Low pressure areas pre-turbo don’t exist, that’s the point. No matter where you tap the system pre turbo you'll get the same pressure.
None of that information changes the fact that you were dead wrong. You stated the sensor would operate normally pre turbo… It won’t. You can dance around 50 topics from farts to airflow all you want… but nothing changes that.
I’m happy your holes don’t get clogged, mine did. Super common on the diesel forums. I figured I’d be fine with ethanol, but wasn’t.
I’m not familiar with bleeding pre-turbo gas to a sensor post turbo. I don’t know how large of a supply line you’d need. If you wanted true WB02 control over every cylinder, even using a 1/16th line on every cylinder would equate to the same thing as drilling a ˝” hole in the exh manifold. Seems like a bad idea IMO… probably why we don’t see it.
None of that information changes the fact that you were dead wrong. You stated the sensor would operate normally pre turbo… It won’t. You can dance around 50 topics from farts to airflow all you want… but nothing changes that.
I’m happy your holes don’t get clogged, mine did. Super common on the diesel forums. I figured I’d be fine with ethanol, but wasn’t.
I’m not familiar with bleeding pre-turbo gas to a sensor post turbo. I don’t know how large of a supply line you’d need. If you wanted true WB02 control over every cylinder, even using a 1/16th line on every cylinder would equate to the same thing as drilling a ˝” hole in the exh manifold. Seems like a bad idea IMO… probably why we don’t see it.
Where ?? really ??
Anywhere pre-turbo will be higher pressure than anywhere outside of that environment. I still cannot fathom how you arent grasping such a simple process.
And NOWHERE did I say a pre sensor turbo would operate normally. I was the first person to say it can be affected by excess heat and pressure, but that doesnt mean it will be completely unusable. It can be used, readings can be affected but it can be used, and I have used it in this way before with no untoward problems whilst tuning some cars.
hell...how much pressure have most in their downpipe where the sensor is installed ? I'm sure few will be zero.
And how many people do you know running one lambda per cylinder as a permanent install ? I dont know of any. Nobody has even asked about such a deal on this thread.
05-17-2016, 02:05 PM
#47
Yup where. Simple question, no? It won’t only be higher pressure, it will be the same pressure. How is a turbo system not a sealed pressure system? I’m not sure how else to explain it? Define a sealed pressure system for us? Is a fuel system a sealed pressure system? A turbo system is very similar to a fuel system. The fuel pressure regulator is doing the same thing a WG is. It’s maintaining a constant pressure in the system…
Your exact words were “it will be fine pre turbo” Then went on to say “I use them pre-turbo quite often when tuning”. To which I say makes very little sense. To someone asking if it’s “ok” to run the WB02 pre turbo… The simple/easy answer is obviously NO.
For example… I’d see over 60psi worth of back pressure at 25lbs on my setup. According to the information posted by Bosch… If my sensor was installed pre turbo, it would indicate over 15% richer than it actually was. So not a good idea IMO.
In the NA world, it’s common to have individual WB’s trimming fuel to each cylinder. Why would you not want that? If sensors were accurate and lived easily in a pre-turbo environment we would see a lot of individual cylinder WB02 setups. But they don’t, and IMO anyone with a clue shouldn’t run a WB02 sensor pre turbo. Which is the whole point.
Your exact words were “it will be fine pre turbo” Then went on to say “I use them pre-turbo quite often when tuning”. To which I say makes very little sense. To someone asking if it’s “ok” to run the WB02 pre turbo… The simple/easy answer is obviously NO.
For example… I’d see over 60psi worth of back pressure at 25lbs on my setup. According to the information posted by Bosch… If my sensor was installed pre turbo, it would indicate over 15% richer than it actually was. So not a good idea IMO.
In the NA world, it’s common to have individual WB’s trimming fuel to each cylinder. Why would you not want that? If sensors were accurate and lived easily in a pre-turbo environment we would see a lot of individual cylinder WB02 setups. But they don’t, and IMO anyone with a clue shouldn’t run a WB02 sensor pre turbo. Which is the whole point.
05-17-2016, 02:23 PM
#48
I love the discussion guys keep it going! Alot of people here can learn from all of this. I really am considering pre-turbo widebands with a pressure transducer and then scaling them accordingly with the equation and K-Factors for rich/lean. Would be interesting to see and compare to a wideband downstream of the turbo (of course each bank will vary slightly and downstream will be a mixture, but you know what I mean.
05-17-2016, 03:43 PM
#50
I am still trying to figure out why. Whats the big advantage? Our brains can compensate for 0.344 seconds of transient delay.
and FWIW I think he meant that the W/G control loop was an open system because air bleeding out of the solenoid leaves to the atmosphere.
and FWIW I think he meant that the W/G control loop was an open system because air bleeding out of the solenoid leaves to the atmosphere.
05-17-2016, 04:48 PM
#51
9 Second Club
No part of any turbo system is sealed !!! Air is constantly moving everywhere....it's how an engine works, it's how a turbo works, it's how boost control works, it's how the whole damn thing works
If no air moved....the engine clearly wouldnt be running.
And why.....clearly you've never had to diagnose problems or fine tune things if you need to ask why.
If you're taking an average of 8 cylinders...can you be sure both banks are working well ?
yes it would be nice to have lambda per cylinder, but it has obvious impracticalities. But It is very easy to have a lambda per bank and tune and monitor on that basis for any issues.
Not doing so, you're just making the assumption all cylinders, both banks are behaving and running as they should. Monitoring and if so desired tuning per bank clearly has benefits for engine health and longevity and you could also say performance.
Strangely when I had the carb intake and elbow, at times one bank would vary from a full AFR point at some light loads, and higher loads at times as much as 0.7 AFR from the other bank.
Never really could nail down why. I changed to one of the shitty BBK SSI intakes at the start of the year and under load now both banks are within 0.3 AFR of each other at worst.
If no air moved....the engine clearly wouldnt be running.
And why.....clearly you've never had to diagnose problems or fine tune things if you need to ask why.
If you're taking an average of 8 cylinders...can you be sure both banks are working well ?
yes it would be nice to have lambda per cylinder, but it has obvious impracticalities. But It is very easy to have a lambda per bank and tune and monitor on that basis for any issues.
Not doing so, you're just making the assumption all cylinders, both banks are behaving and running as they should. Monitoring and if so desired tuning per bank clearly has benefits for engine health and longevity and you could also say performance.
Strangely when I had the carb intake and elbow, at times one bank would vary from a full AFR point at some light loads, and higher loads at times as much as 0.7 AFR from the other bank.
Never really could nail down why. I changed to one of the shitty BBK SSI intakes at the start of the year and under load now both banks are within 0.3 AFR of each other at worst.
05-18-2016, 09:37 AM
#52
The point was there is a constant pressure applied to all areas pre-turbo, there is no area low/high pressure areas pre turbo. There is 1 single pressure set by the WG. So installing a WB02 in any sort of chamber/stand pipe etc will not lower the pressure the the sensor is exposed to. (that does not of course apply if you are bleeding pressure to a low pressure area post turbo)
05-18-2016, 09:47 AM
#53
9 Second Club
OK...a tyre is a sealed system, and yes a balloon.
And you could say a fuel system is sealed...up to the injectors...where they too leak from a high pressure area to a low pressure. And in the intake manifold that fuel is no longer at high pressure.
So again, that simple movement from high to low.
And there is a high to low pressure area created by using a hole to feed air from the high pressure manifold to a low pressure area...ie downpipe or atmosphere via the sampling chamber, which has been repeated to death now and others have grasped and understood quite clearly.
And for the billionth time.....you bleed off air from the boost control setup, you control/regulate it's movement to the w/g to trick it into seeing a lower pressure so it operates differently than if it was directly fed manifold pressure only.
It's the same thing very very simple thing.
And you could say a fuel system is sealed...up to the injectors...where they too leak from a high pressure area to a low pressure. And in the intake manifold that fuel is no longer at high pressure.
So again, that simple movement from high to low.
And there is a high to low pressure area created by using a hole to feed air from the high pressure manifold to a low pressure area...ie downpipe or atmosphere via the sampling chamber, which has been repeated to death now and others have grasped and understood quite clearly.
And for the billionth time.....you bleed off air from the boost control setup, you control/regulate it's movement to the w/g to trick it into seeing a lower pressure so it operates differently than if it was directly fed manifold pressure only.
It's the same thing very very simple thing.
05-18-2016, 10:03 AM
#54
I don’t’ see where the “system” part comes in when referring to an inanimate object like a tire/balloon. That isn’t how the term is used. At least over here in the US, you guys do things funny over there… 
Maybe you call it a Constant pressure system or something.
So just like the “sealed” fuel system you mention… The turbo system is no different. The turbo is taking the place of the injectors. So as I’ve said 100 times now, pre-turbo it IS considered a sealed pressure system. Then the gas is driven through the turbo into a lower pressure area post turbo. Pre-turbo is a constant pressure throughout the system. So placing the sensor before the turbo is not a good idea, which is the point of the thread.
You are obsessed with this boost control thing huh? What does that have to do with WB02 sensors installed pre turbo again?
Saying something is “simple” repeatedly does nothing to further press your point. I was asking “simple” questions to further argue my point, not because I didn’t know the answers to the questions I asked. I’m not sure you follow the point I was trying to make. I know how the system works and the answer the original question asked. Writing it down and explaining why for others to understand is always more difficult.
I’m not saying you don’t understand, just that I disagree with some of the misleading statements you made. Which I quoted above. Bringing up instances where something like this could work doesn’t answer the main question/topic. My statements do… IMO anyway.
Maybe you call it a Constant pressure system or something. So just like the “sealed” fuel system you mention… The turbo system is no different. The turbo is taking the place of the injectors. So as I’ve said 100 times now, pre-turbo it IS considered a sealed pressure system. Then the gas is driven through the turbo into a lower pressure area post turbo. Pre-turbo is a constant pressure throughout the system. So placing the sensor before the turbo is not a good idea, which is the point of the thread.
You are obsessed with this boost control thing huh? What does that have to do with WB02 sensors installed pre turbo again?
Saying something is “simple” repeatedly does nothing to further press your point. I was asking “simple” questions to further argue my point, not because I didn’t know the answers to the questions I asked. I’m not sure you follow the point I was trying to make. I know how the system works and the answer the original question asked. Writing it down and explaining why for others to understand is always more difficult.
I’m not saying you don’t understand, just that I disagree with some of the misleading statements you made. Which I quoted above. Bringing up instances where something like this could work doesn’t answer the main question/topic. My statements do… IMO anyway.
Last edited by Forcefed86; 05-18-2016 at 10:22 AM.
05-18-2016, 10:14 AM
#55
I'm loving it. Makes me feel better about the ridiculous fighting in the "Highest HP Bolt-On" dyno thread that I got into 
It seems like if you're going to go through the trouble to weld a tube onto the manifold pre-turbo to a bung to the downpipe, just to get a wideband on it, why not just got EGT probes per cylinder and be done with it.
It seems like if you're going to go through the trouble to weld a tube onto the manifold pre-turbo to a bung to the downpipe, just to get a wideband on it, why not just got EGT probes per cylinder and be done with it.
05-18-2016, 11:25 AM
#56
9 Second Club
I don’t’ see where the “system” part comes in when referring to an inanimate object like a tire/balloon. That isn’t how the term is used. At least over here in the US, you guys do things funny over there… Maybe you call it a Constant pressure system or something.
So just like the “sealed” fuel system you mention… The turbo system is no different. The turbo is taking the place of the injectors. So as I’ve said 100 times now, pre-turbo it IS considered a sealed pressure system. Then the gas is driven through the turbo into a lower pressure area post turbo. Pre-turbo is a constant pressure throughout the system. So placing the sensor before the turbo is not a good idea, which is the point of the thread.
You are obsessed with this boost control thing huh? What does that have to do with WB02 sensors installed pre turbo again?
Saying something is “simple” repeatedly does nothing to further press your point. I was asking “simple” questions to further argue my point, not because I didn’t know the answers to the questions I asked. I’m not sure you follow the point I was trying to make. I know how the system works and the answer the original question asked. Writing it down and explaining why for others to understand is always more difficult.
I’m not saying you don’t understand, just that I disagree with some of the misleading statements you made. Which I quoted above. Bringing up instances where something like this could work doesn’t answer the main question/topic. My statements do… IMO anyway.
Maybe you call it a Constant pressure system or something. So just like the “sealed” fuel system you mention… The turbo system is no different. The turbo is taking the place of the injectors. So as I’ve said 100 times now, pre-turbo it IS considered a sealed pressure system. Then the gas is driven through the turbo into a lower pressure area post turbo. Pre-turbo is a constant pressure throughout the system. So placing the sensor before the turbo is not a good idea, which is the point of the thread.
You are obsessed with this boost control thing huh? What does that have to do with WB02 sensors installed pre turbo again?
Saying something is “simple” repeatedly does nothing to further press your point. I was asking “simple” questions to further argue my point, not because I didn’t know the answers to the questions I asked. I’m not sure you follow the point I was trying to make. I know how the system works and the answer the original question asked. Writing it down and explaining why for others to understand is always more difficult.
I’m not saying you don’t understand, just that I disagree with some of the misleading statements you made. Which I quoted above. Bringing up instances where something like this could work doesn’t answer the main question/topic. My statements do… IMO anyway.
I'm not obsessed with anything....I'm simply explaining both aspects are controlling simple movement of air
And if you want to use the fuel system analogy...which works. With the turbo being the injectors...the FPR being the control orifice, and the sesnor being installed on the return line...the return line being the line to/from and including the sampling chamber.
From your posts, you seem to insist this return line will be at the same pressure as that prior to the FPR...ie the control orifice. Which you know it will not be.
So doesnt matter a damn whether it's air, fuel, exhaust, fart, all the same principals apply.
And your description of the turbo setup is NOT sealed. The turbo itself is the control orifice in this case where the transition from high pressure to low pressure takes place...ie it's a huge leak for your "sealed" system, as is the wastegate itself, so you've two huge leaks there.
Sealed to me means no leaks.
05-18-2016, 12:39 PM
#57
I said a stand pipe extended to any length off the manifold would be at the same pressure as the rest of the manifold, which is true. I never mentioned a restricted line leading to the Downpipe connecting the two. That low pressure line is no longer pre-turbo as it connects post turbo. It should not be associated with the system pre-turbo.
Either way, that is not the original topic of discussion. We were talking about the OP simply tossing a sensor in the system pre turbo. To which you mention is fine and you do it occasionally to tune because it’s easy.
Sealed pressure system is a common automotive term and can be used to describe fuel systems, hyd systems, cooling systems turbo systems etc. Because you chose to interpret it literally, that doesn’t mean my terminology is incorrect. It means you are unfamiliar with the term and how it is used. A monkey wrench isn’t used on monkeys… I guess it could be, but you get my point!
Either way, that is not the original topic of discussion. We were talking about the OP simply tossing a sensor in the system pre turbo. To which you mention is fine and you do it occasionally to tune because it’s easy.
Sealed pressure system is a common automotive term and can be used to describe fuel systems, hyd systems, cooling systems turbo systems etc. Because you chose to interpret it literally, that doesn’t mean my terminology is incorrect. It means you are unfamiliar with the term and how it is used. A monkey wrench isn’t used on monkeys… I guess it could be, but you get my point!
05-19-2016, 04:59 PM
#58
However, it is also true that when we build models for these systems, we still consider them "closed" so that we can work with the numbers easily. Often there is a constant "leak rate" we can adjust which will make the model more realistic, once we have the majority of it figured out. A good example well known is the PV=nrt, everyone knows that PV=nrt, however this equation is not "realistic" since it does not include the math that relates the size of gas molecules to their cumulative effect on pressure/volume relationship. So sometimes models and equations are "dumbed down" for the sake of simplicity, and it is up to us to know when to adjust our model for more realistic situations (when every number counts).
And why.....clearly you've never had to diagnose problems or fine tune things if you need to ask why.
If you're taking an average of 8 cylinders...can you be sure both banks are working well ?
If you're taking an average of 8 cylinders...can you be sure both banks are working well ?
05-19-2016, 05:17 PM
#59
9 Second Club
One wideband on each side, after each downpipe. Why would I try putting them pre-turbo with all the extra equipment/hassle/question when I can weld a bung into the downpipe 5' away from all that mess/heat and be done with it? The accuracy is not a problem because we built the engine, we know the compression is even, we tested the injectors and broke them in on a bench, we verified both sides are leak free with pressure tests, the plugs all look identical, and so forth (anything you consider worthy of Individual wideband surely is a high dollar project with all of these attributes far more important). And, anything an individual cylinder wideband would tell you (not even the point of the thread, but...) if bad enough will show up in the compression/plug/behavior/feel/tone of the engine. Diagnostics should not be limited to wideband sensors; we've been building and tuning engines since before a wideband ever appeared on an engine.
And you will never need to keep an eye on it via any means....at any time, either when tuning, driving about, racing....never.
Bull ******* ****.
And you must not have much faith in your meticulously built and prepared engines if you're then saying you need to check plugs, check compression etc quite archaic means really compared to monitoring health and running in real time !
Some of your posts really do get worse and worse.