Don Terrill’s Speed-Talk

Have a nitrous BBC lookin at adding O2 sensors for better tuning at track and being more consistent run to run , do not have a Race Pak in car so looking at some of the data recording O2 sensors from big stuff3 and altronics? anyone running or using any thing like this ? pros? cons? Any advice would help like to find what is best and spend money once Thanks

Innovate LM2 is the most simple, one or two channel, an adaptor cable and it records RPM, and with an add on box it will data record extra channels of what ever you like.

Be aware ... O2 sensors do NOT actually measure air / fuel ratios but, merely the oxygen remaining in the exhaust gas.

They are not the same things but, O2 sensors can read close air /fuel if it is not grossly rich or lean.

I have the LM2 and pocket recorder, works pretty good and can play back on laptop from the sd card.

They don't even measure the oxygen content when richer than lambda 1.
They measure the % of combustibles.

EGT sensors are better, more accurate, more reliable, cheaper and they're industry standard.
WB sensors are over rated, go faulty, change readings etc.

It's not going to harm using them but you certainly wouldn't want to rely on them as your only instrumentation.


I've got one(innovative) on one of my cars, I've also got EGT as well as a calibrated Bosch NB o2 sensor.

Use all 3 together.


An engine dyno, you'd expect to use everything available, depending on budget.

joe 90 wrote:EGT sensors are better, more accurate, more reliable, cheaper and they're industry standard.
WB sensors are over rated, go faulty, change readings etc.

It's not going to harm using them but you certainly wouldn't want to rely on them as your only instrumentation.


I've got one(innovative) on one of my cars, I've also got EGT as well as a calibrated Bosch NB o2 sensor.

Use all 3 together.


An engine dyno, you'd expect to use everything available, depending on budget.

Again, the professional motorsports world, from NASCAR to F1 is doing it all wrong relying on information from a wide band sensors huh?!? Lol
And just what useful AFR tuning information are the EGTs going to provide over a wide band lamda?!?

If you can really streeeetch your budget , O2 and EGT sensors together are a must, the combination of their data tells more than one or the other used singularly . unfortunately you are heading into dedicated data logging equipment territory, the benefit to your tune from day one will surprise you but what will possibly swing you to data logging is detecting a fault before it costs an engine.
And if you can really really streeeeetch it ,drive line sensors will show you which bin you are tipping your ET into.
Many years ago when we wrote everything down and tried to make sense of it all, only to find something contradicted what we thought we had already proven ,the need for a data logger became desirable and like you, we agonized over how to keep it simple ,eventually over a couple of years the owners bit the bullet and bought a dedicated system ,,, the difference was chalk and cheese once it was sorted out ,to the point what we thought were neat little tricks turned out to be ,,,,hmmmm ,,, how do i put it? i would have to say data is king , after a pass the download was read before anything was touched.


Cheers.

EGT sensors are better, more accurate, more reliable, cheaper and they're industry standard.

Can you reveal just what information you think is obtained from an EGT and why is it useful? They are certainly useless as far as mixture tuning is concerned.

Lambda sensors can be used with very good accuracy if properly used. Most are not.
An O2 sensor should be inserted in each exhaust pipe at about the same location.
The sensor should indicate tip temperature and be self correcting.
A sample rate of 1000 Hz is very useful; it should be recorded along with throttle position and rpm.

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,

You do know that you can have the same target burn rate and afr in all cylinders and still have vastly varying egts from cylinder to cylinder.......?

If you've got even combustion and even AFRs then you'll have even EGTs.


If you go and mess it up with uneven fuel distribution or bad atomisation, then you'll end up with uneven EGTs.



Starting off with something that works properly and adding instruments and watching what happens (with mods) is far better than starting with a POS and trying to fix it by adding instruments.

joe 90 wrote:If you've got even combustion and even AFRs then you'll have even EGTs.

In theory!
Unfortunately, in the real world, that is NOT the way it is!

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?

Warp Speed wrote:

joe 90 wrote:If you've got even combustion and even AFRs then you'll have even EGTs.

In theory!
Unfortunately, in the real world, that is NOT the way it is!

Actually, if you have even combustion and even mixtures you will have even EGTs. But, no engine has even combustion and even mixtures. Every engine has large cycle to cycle variances as well as cylinder to cylinder variances.

Ignition timing, or more precisely combustion timing, has the greatest single influence on EGTs. But throttle position (including air flow past each throttle at every angle), engine RPM, inlet air temperature, and length of time at full throttle will drive the EGT measurement. A thermocouple located in a single exhaust pipe will produce a different reading than one inserted in a collector. Add to the mix the fact that a TC can only give a time weighted average reading in a pulsed flow exhaust, which is far from being the actual temperature.

The above have been observed many times using high speed data logging. Hook up a TPS, inlet air temp, ignition angle, RPM, EGT and O2 to a quality data logger (AIM, MoTec) and try to find positive correlations. Since the data is very jittery, it takes some concentrated analysis to understand what is actually happening.

And, if you can, also hook up an in-cylinder TFX combustion pressure sensor.

I am not trying to discourage anyone from attempting to understand; I am saying that we must dig deeper to find the truth.