Fuel Air Mixture Wide Band System

[DaveEFI]

This is the sequence nicked from the MS forum.

[GDCobra]

This is the sequence nicked from the MS forum.

Interesting, I may look at making up a loom to try this out on mine. Just making up some extensions to swap over sides would be all that's needed to check if the benefit is worth going any further.

On the MS, is the injector timing synchronised to the engine position in any way, obviously it won't be timed for each cylinder as it's bank fire, just wondering if there is any set timing or if just fires "at some point(s)" during the revolution.

On the 14CUX I don't think the injection event is deliberately timed to the engine position but as the calculation is triggered by the ignition event and should always take a similar time for the calculation I guess that would mean the injection will always occur at a specific point in the engine cycle but whether that would be beneficial or not is anyones guess.

[DaveEFI]

With a distributor, the injection has no way of knowing which cylinder is firing, as all it gets is ignition firing pulses. But could trigger each time at the same spacing from the pulses. But then most will be two squirts alternating, so doubt it makes any difference in practice. Just why grouping the injectors in the way I've given makes a difference, I'm not sure. But since it cost me nothing, gave it a go.

[stevieturbo]

Can you explain what fault could cause one bank to run lean (or whatever)?

wiring issue, injector issue, valvetrain issue, air leak as already shown...like basically anything that is part of the engines operation ? Like is that even a serious question ?

[stevieturbo]

I have an Innovate controller, must admit I've not heard of them being particularly problematic (but that may just have passed me by), do you know which units are fault prone and how they tend to fail?
Do you know if the Innovate controller is the issue or is it the sensor? I have heared that the earlier sensors (4.2 LSU) can be a bit delicate but the 4.9LSU is more robust.

It is very worthwhile reading both banks, it matters not if you think you cannot make changes per cylinder or per bank...but as a diagnostic and tuning tool if you only monitor one bank, you assume the other is doing the same. And if there are faults or problems, it can be handy to give an indication as to which bank has a problem.
When it is so easy to do...it makes sense to view both banks

Not sure if I gave some ambiguous information in my previous post which appeared to disagree with this so I'll clarify.
I totally agree that both banks should be tested however I don't think this needs to be continuously or simultaneously. When I did some testing on mine both banks were monitored and gave similar results in similar tests however this was performed by switching the sensor from side to side and repeating the test. This definitely should be done to ensure there is not airleak or falty injector on one bank and probably repeated periodically to ensure nothing changed, but once the banks are proven equal it should be OK.
Obviously it would be better to monitor both banks simultaneously but more costly and with the Innovate controller being quite large there would also be issues with space. It seems current technology has allowed these to shrink now so that's possibly less of a problem.

I would say the 4.2 is more robust than the 4.9, and cheaper.

If you have an LC1, you could just buy another and view both on a laptop, that is about your cheapest option.

No it is not essential to monitor anything all the time....but does it do no harm to have those gauges in the car ? Not really...other than perhaps making you paranoid if you see anomalies.
Just depends whether you're a fit and forget type of person, or someone always interested in what is going on, and monitoring health and performance. Sometimes ignorance is bliss

Innovate do a dual round gauge, so takes up no more room than any other gauge

https://www.innovatemotorsports.com/products/dlg1.php

Or their ugly dash mounted/portable dual unit....although as you already have sensor, a single kit would be all you need, and maybe an additional lead

https://www.innovatemotorsports.com/products/lm2.php

The long standing problem with Innovate...is they control the sensor their own way...and often this leads to premature sensor failure.

FAST do a not too ugly rectangular gauge

https://www.jegs.com/i/FAST/244/170402/10002/-1

Zeitronix do kit and gauge where you can display multiple items, so 2 x AFR would be easy

https://zeitronix.com/Products/LCD/LCD.shtml

I'm sure the 1.47 guy Dave mentioned would offer something too and probably cheaper.

PLX offer a wide range of gauges, displays etc....even one for a smartphone now it seems

https://www.plxdevices.com/PLX-Wideband ... -s/125.htm

Really...there are no lack of options.

[GDCobra]

I have an Innovate controller, must admit I've not heard of them being particularly problematic (but that may just have passed me by), do you know which units are fault prone and how they tend to fail?
Do you know if the Innovate controller is the issue or is it the sensor? I have heared that the earlier sensors (4.2 LSU) can be a bit delicate but the 4.9LSU is more robust.

It is very worthwhile reading both banks, it matters not if you think you cannot make changes per cylinder or per bank...but as a diagnostic and tuning tool if you only monitor one bank, you assume the other is doing the same. And if there are faults or problems, it can be handy to give an indication as to which bank has a problem.
When it is so easy to do...it makes sense to view both banks

Not sure if I gave some ambiguous information in my previous post which appeared to disagree with this so I'll clarify.
I totally agree that both banks should be tested however I don't think this needs to be continuously or simultaneously. When I did some testing on mine both banks were monitored and gave similar results in similar tests however this was performed by switching the sensor from side to side and repeating the test. This definitely should be done to ensure there is not airleak or falty injector on one bank and probably repeated periodically to ensure nothing changed, but once the banks are proven equal it should be OK.
Obviously it would be better to monitor both banks simultaneously but more costly and with the Innovate controller being quite large there would also be issues with space. It seems current technology has allowed these to shrink now so that's possibly less of a problem.

I would say the 4.2 is more robust than the 4.9, and cheaper.

If you have an LC1, you could just buy another and view both on a laptop, that is about your cheapest option.

No it is not essential to monitor anything all the time....but does it do no harm to have those gauges in the car ? Not really...other than perhaps making you paranoid if you see anomalies.
Just depends whether you're a fit and forget type of person, or someone always interested in what is going on, and monitoring health and performance. Sometimes ignorance is bliss

Innovate do a dual round gauge, so takes up no more room than any other gauge

https://www.innovatemotorsports.com/products/dlg1.php

Or their ugly dash mounted/portable dual unit....although as you already have sensor, a single kit would be all you need, and maybe an additional lead

https://www.innovatemotorsports.com/products/lm2.php

The long standing problem with Innovate...is they control the sensor their own way...and often this leads to premature sensor failure.

FAST do a not too ugly rectangular gauge

https://www.jegs.com/i/FAST/244/170402/10002/-1

Zeitronix do kit and gauge where you can display multiple items, so 2 x AFR would be easy

https://zeitronix.com/Products/LCD/LCD.shtml

I'm sure the 1.47 guy Dave mentioned would offer something too and probably cheaper.

PLX offer a wide range of gauges, displays etc....even one for a smartphone now it seems

https://www.plxdevices.com/PLX-Wideband ... -s/125.htm

Really...there are no lack of options.

Thanks for that Steve, some good information there.

I must admit I've got a bit caught up with this thread as it's something I'm looking at myself at the moment and I'm really "thinking out loud" on some parts of this rather than putting a plan together for myself, as such I should probably reign myself in a little.

I'm not too concerned with constantly monitoring the ARF, I'm really only interested in it when I make changes to anything which may affect the value and to periodically check that nothing is changing. As such performing separate tests for each bank is no big deal.
I can do this with a laptop but it can be a bit clumsy in my car as space is limited, also not easy/safe to keep looking sideways to view the reading. The wireless link to a phone app would be perfect for my use, I wish there was a way to link that to my current system rather than a new purchase.
All I really need is a meter which I should be able to add to my Innovate system, I guess I could just use a volt meter and mark it up for AFR.

While looking into this I found some information on the affects of AFR and/or ignition timing on the abilty to make power, turns out AFR is actually not that important for this (it's more related to allowing the engine to do so without grenading itself) and timing is more important for the job of optimising power output. Not sure if this is completely true but the explanation did make some sense.

[DaveEFI]

My Rover SD1 originally had the Lucas 4CU injection. It went very well on full throttle and once the revs got up - but always felt a bit flat at low revs for a V8. And being an auto, using a lot of throttle would make it change down. It's something I'd also read on contemporary road tests.

I fitted my Tech Edge unit before the MS. And it showed why. At low revs with say as much throttle as you could use before forcing a change down, it was running very weak. Maybe to squeeze the very best MPG figures for tests.

MS allows you to map what you want. Richening the mixture under those conditions transformed the car - it now pulls like you'd expect a V8 to do. Very noticeable on some hills where it would now climb them in top gear - before it would change down.

Timing is important - but so is the AFR, perhaps even more so where you can fully map the injection. And a decent wideband take much of the guessing out of tuning.

[GDCobra]

My Rover SD1 originally had the Lucas 4CU injection. It went very well on full throttle and once the revs got up - but always felt a bit flat at low revs for a V8. And being an auto, using a lot of throttle would make it change down. It's something I'd also read on contemporary road tests.

I fitted my Tech Edge unit before the MS. And it showed why. At low revs with say as much throttle as you could use before forcing a change down, it was running very weak. Maybe to squeeze the very best MPG figures for tests.

MS allows you to map what you want. Richening the mixture under those conditions transformed the car - it now pulls like you'd expect a V8 to do. Very noticeable on some hills where it would now climb them in top gear - before it would change down.

Timing is important - but so is the AFR, perhaps even more so where you can fully map the injection. And a decent wideband take much of the guessing out of tuning.

I'll see if I can find the information I was looking at and post a link but that's slightly different to what was being said.

As we all know Stoiciometric/14.7:1 is the ideal ratio for burning gasoline/petrol (possibly not the low-fat Ethanol rich garbage we now have), in those proportions all the fuel will be burned and all the oxegen will be consumed by it hence you will get the best bang for your buck. Literally.
What this guy was saying is if we add more fuel it won't make more power as there is no more oxegen to burn it, this is what I was talking about when I said AFR does not contribute as much as we may think to making power.

As you mention above your issue was running lean, the same reasoning follows here, your engine will have been burning all the fuel (or at least all the fuel which was 'burnable') but would not be using all the air, this would give similar behaviour to having a smaller cylinder running stoiciometric and of course a smaller engine would make less power.
I'm sure there would be other factors coming to play such as the leaner mixture just not burning as well due to problems getting it lit and so on but that was the overall result just taking into account AFR.

The reason given for running richer when we want to make more power is to keep the engine cool (and not grenade) rather than to burn for more power. Which did get me thinking if there were some less expensive/tax-attracting substance which could be added for that capabilty rather than the beautiful substance that is petrol! Snake oil would probably work but that's not cheap either.

[DaveEFI]

For best power, you'd normally go to something like 12.5:1. Best economy about 15.5:1. Assuming no catalytic converter to worry about.

[GDCobra]

For best power, you'd normally go to something like 12.5:1. Best economy about 15.5:1. Assuming no catalytic converter to worry about.

I agree that is what you would do BUT what was being suggested is that if you monitored that high power condition on the dyno and wound the ARF from 12.5 to 14.7 you would not get much difference in power output and probably not in the direction you want. What would happen is that your engine would not last very long, that extra fuel from the richer mixture is being used to improve engine life by cooling the cylinder when it is being asked to make lots of power, rather than actually making power.
Obviously any extra mechanicl power you see at the engine output will be matched by a proportional (or greater) increase in heat inside the engine.

I don't quite see why a leaner mixture would give better fuel economy. Obviously less fuel is being supplied but that would also produce less power which would result in a higher demand from the right foot and hence more fuel going in again. I guess someone with longer trouseres than mine can explain that.

[DaveEFI]

With a lean mixture and low load, you can use more ignition advance. Both of which aid economy.

And richer than stoic produces more torque at low revs too.

If stoic was ideal under all conditions, a simple lambda sensor would suffice. Same as you have on a cat engine.

[stevieturbo]

14.7 is largely only the cleanest, not the most powerful, not the best, not whatever.

Ultimately the engine will want whatever it wants to be optimised. AFR's will have less of an effect on power, but you'd still want them in a sensible range for power and reliability. Leaner may make more power to a point....but then that point is also risk of engine damage, and you don't want any cylinders to be there.

But there is also the caveat ( less important for low power sort of stuff really ) than even with 1 or 2 widebands, you just assume all cylinders will run evenly. There is plenty of data out there with tests and say 8 widebands.....that there can be a huge variation between cylinders.

Ultimately it may not affect power so much....but say you tune to an average of 12 on a boosted engine, which is a little on the lean side. Some cyls might be at 11...some might be at 13...then people wonder why they melt pistons

Less of an issue on a low power motor though.

For most 8 is obviously not practical....but 2 is very easy on a V8 and not particularly cost prohibitive. When it is so easy to do....I see no reason not to do if you're genuinely interested in how the engine lives.
Would you need them installed forever ? probably not, again it just depends on your level of interest.

Many run with nothing....as said, often ignorance is bliss.

[Robrover]

I have an AEM wideband on my 4.6 SD1 with Edelbrock 1404. Very useful tool in getting the jetting spot on. Starts first time, good idle even with a hot cam and race heads, and goes like stink when the accelerator pump cuts in.