Air fuel ratio 02 sensors for data

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carmakerevive
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Re: Air fuel ratio 02 sensors for data

Post by carmakerevive »

^I've seen a few instances where a tuner has insisted on knock sensors, only to be unable to hear knock correctly when the engine is running also. or they've taken so long to identify the particular sound of pre-ignition that the length tune has blown out to weeks worth of labour.

And EGT's would be useful channel to log on a diesel engine, or perhaps a turbocharged one...but even then, i'd still prefer a wideband lambda anyday over an EGT channel...
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Re: Air fuel ratio 02 sensors for data

Post by user-23911 »

Belgian1979 wrote:
I have got a question : if you can hear valvetrain noise outside of the engine bay, why wouldn't a knock sensor not hear that noise ? After all, it's a microphone attached to the engine.


There's 2 sorts of knock sensors, one is a microphone, the other isn't. It's more like an electronic tuning fork.
They work in completely different ways, most people have no clues?
The GM ones work best which are electronic tuning forks, They don't listen for a particular frequency, they detect the initial shock wave at zero Hz.
The microphone ones, all the published theory is completely wrong so they usually don't work.


An EGT sensor is pretty much standard equipment on a truck engine or industrial engine or even gas turbine.
A WB sensor isn't.
Need to think on that for a while.
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Re: Air fuel ratio 02 sensors for data

Post by Belgian1979 »

joe 90 wrote:
Belgian1979 wrote:
I have got a question : if you can hear valvetrain noise outside of the engine bay, why wouldn't a knock sensor not hear that noise ? After all, it's a microphone attached to the engine.


There's 2 sorts of knock sensors, one is a microphone, the other isn't. It's more like an electronic tuning fork.
They work in completely different ways, most people have no clues?
The GM ones work best which are electronic tuning forks, They don't listen for a particular frequency, they detect the initial shock wave at zero Hz.
The microphone ones, all the published theory is completely wrong so they usually don't work.


An EGT sensor is pretty much standard equipment on a truck engine or industrial engine or even gas turbine.
A WB sensor isn't.
Need to think on that for a while.
Both sensors you refer to are the same type. One of them however is tuned to a specific engine because they filter out other sound frequencies. That's it no more, no less.
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Re: Air fuel ratio 02 sensors for data

Post by Belgian1979 »

carmakerevive wrote:^I've seen a few instances where a tuner has insisted on knock sensors, only to be unable to hear knock correctly when the engine is running also. or they've taken so long to identify the particular sound of pre-ignition that the length tune has blown out to weeks worth of labour.

And EGT's would be useful channel to log on a diesel engine, or perhaps a turbocharged one...but even then, i'd still prefer a wideband lambda anyday over an EGT channel...
I found that knock sensors are better adapted at detecting valve train issues rather than distinguishing knock :D
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Re: Air fuel ratio 02 sensors for data

Post by user-23911 »

Belgian1979 wrote: Both sensors you refer to are the same type. One of them however is tuned to a specific engine because they filter out other sound frequencies. That's it no more, no less.

100% completely wrong.=fail.
Belgian1979 wrote:
carmakerevive wrote:^I've seen a few instances where a tuner has insisted on knock sensors, only to be unable to hear knock correctly when the engine is running also. or they've taken so long to identify the particular sound of pre-ignition that the length tune has blown out to weeks worth of labour.
I found that knock sensors are better adapted at detecting valve train issues rather than distinguishing knock :D
That's what happens when people don't know WTF they're doing.
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Re: Air fuel ratio 02 sensors for data

Post by Belgian1979 »

joe 90 wrote:
Belgian1979 wrote: Both sensors you refer to are the same type. One of them however is tuned to a specific engine because they filter out other sound frequencies. That's it no more, no less.

100% completely wrong.=fail.
Belgian1979 wrote:
carmakerevive wrote:^I've seen a few instances where a tuner has insisted on knock sensors, only to be unable to hear knock correctly when the engine is running also. or they've taken so long to identify the particular sound of pre-ignition that the length tune has blown out to weeks worth of labour.
I found that knock sensors are better adapted at detecting valve train issues rather than distinguishing knock :D
That's what happens when people don't know WTF they're doing.
Over the time that I've been a member and have seen you comment, I have seen more wrong things written by you than correct things. Others have already demonstrated that more than once.
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Re: Air fuel ratio 02 sensors for data

Post by redliner »

Warp Speed wrote:
hoodeng wrote:One feature of EGT when used in conjunction with O2 is when ,O2 is stable and there is a rise in EGT could indicate on the system i used, timing being later than ideal, and if the EGT was less than our target would indicate advanced timing from ideal , of course other factors were to be taken into account as data is holistic so a negative impact on ET with all other parameters in scope would narrow down an area to be investigated.If you do go down the data logging route ,first up you will be swamped with a sea of lines that will make you go quiet for a while ,,but it will make sense once sorted.
If you can ,source your system from a supplier that gives backup ..When we had trouble in the early days of a new bike ,the guys that supported that data logging brand were also running a vehicle at similar meetings so i was extremely lucky to have these guys a few pits away.
All data is singular vehicle relevant pretty much as guys that run multiple vehicles know ,what worked on one does not necessarily mean another vehicle of the same type would respond exactly the same with the same interpretations.

Bit like weather stations , yours might not be 'Bureau of Meteorology' correct but if it is consistent it will be observations relevant to your vehicle ,,,, i could never work out what people were looking for when they compared weather stations????

All that said , data monitoring and recording your exhaust to start with is a mighty big step in the right direction just by itself!!!

Cheers,
How do you come up with an EGT target temp?
EXACTLY!!!!!
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Re: Air fuel ratio 02 sensors for data

Post by user-23911 »

redliner wrote:
Warp Speed wrote: How do you come up with an EGT target temp?
EXACTLY!!!!!
Through testing and tuning.

EGT is always hottest at a lambda of 1.
No excess of air and no excess of fuel,it's all being used.
It's cooler when lean and it's cooler when rich.

As to how hot, it depends on the engine, fuel type, RPM and load.
Full throttle is hotter than part throttle, peak torque RPM is hotter than higher or lower RPM.

That's all when the timing is tuned correctly.
Less timing advance will be hotter, more timing advance = broken.
That's what the knock sensor is for.


How about piston engined aircraft?

WB 02 or EGT?

https://aviation.stackexchange.com/ques ... ch-or-lean
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Re: Air fuel ratio 02 sensors for data

Post by digger »

Depends on your priorities. Last time checked it's not one or the other generally speaking
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Re: Air fuel ratio 02 sensors for data

Post by Warp Speed »

joe 90 wrote:
redliner wrote:
Warp Speed wrote: How do you come up with an EGT target temp?
EXACTLY!!!!!
Through testing and tuning.

EGT is always hottest at a lambda of 1.
No excess of air and no excess of fuel,it's all being used.
It's cooler when lean and it's cooler when rich.

As to how hot, it depends on the engine, fuel type, RPM and load.
Full throttle is hotter than part throttle, peak torque RPM is hotter than higher or lower RPM.

That's all when the timing is tuned correctly.
Less timing advance will be hotter, more timing advance = broken.
That's what the knock sensor is for.


How about piston engined aircraft?

WB 02 or EGT?

https://aviation.stackexchange.com/ques ... ch-or-lean
Aircraft use EGTs to keep the engine safe, not for maximum performance!
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Re: Air fuel ratio 02 sensors for data

Post by In-Tech »

As noted a few times in this thread, EGT is worth monitoring but is not the "end all" tuning guage. 8 WBo2's and 8 egt's will teach you some things. Doing CARB certification we will have the cylinders within a 1/4 AFR and EGT all over the place...hmm, why is that? It's because one cylinder will have more mass flow than another depending on rpm and load(ya know, pulses in the manifold). This also drastically changes with a bigger cam/overlap and also why OEM's generally have little overlap. That little overlap and late IVC event sure comes into play doesn't it? =D>
Heat is energy, energy is horsepower...but you gotta control the heat.
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Re: Air fuel ratio 02 sensors for data

Post by Firedome8 »

does pre ignition knock ?
A good test is worth a thousand opinions.
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Re: Air fuel ratio 02 sensors for data

Post by Belgian1979 »

In-Tech wrote:As noted a few times in this thread, EGT is worth monitoring but is not the "end all" tuning guage. 8 WBo2's and 8 egt's will teach you some things. Doing CARB certification we will have the cylinders within a 1/4 AFR and EGT all over the place...hmm, why is that? It's because one cylinder will have more mass flow than another depending on rpm and load(ya know, pulses in the manifold). This also drastically changes with a bigger cam/overlap and also why OEM's generally have little overlap. That little overlap and late IVC event sure comes into play doesn't it? =D>
correct. Fully agree.
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Re: Air fuel ratio 02 sensors for data

Post by Belgian1979 »

Firedome8 wrote:does pre ignition knock ?
No, but it sure does heat up things and that could lead to...:lol:
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Re: Air fuel ratio 02 sensors for data

Post by The Radius Kid »

You guys are still weird.
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