Product Idea

[SILVER2000SVT]

I’m planning to put an Autometer air-fuel gage in my Lightning. I don’t like the idea of having to choose only one side to get the reading from. So, I’m in the process of building a circuit that will read both. Right now the design has 2 solid colored LEDS and 1 multi colored LED and a small push button switch. It will have 4 modes where the switch toggles between modes. Mode 1 reads signals from both left and right O2 sensors and sends out which ever on is lower to the gage, it will also light up the corresponding solid colored LED for which signal it is using. Mode 2 will do the same as Mode 1 except it will use the higher of the two signals. Mode 3 will simply output the left O2 signal to the gage, and Mode 4 will output the right O2 signal. The multi colored Led will light up different colors to indicate which of the modes it is in.

I’m just looking for opinions and input. Has this been done before? Do you think other people would be interested in something like this? Maybe once I get it working, I can sell a few of them?

Jason

[microsuck]

yeah, I did that. I did it with an intercooler fluid temp gauge though. mine has two sending units one for water coming out of the intercooler and one for water going into it. a switch directs the the desired wire to the gauge in the steering column pod. the only downside is that my gauge has a "highest temp" recall. and when you switch to the outgoing water unit it stores that as the hottest, not the hottest going in. but that is stupid anyways.

Andrew

[SILVER2000SVT]

Andrew,

You said you did yours with a manual switch?

If I build it like I want to, It will be dynamic. I figure I would pretty much use it mainly in the mode where it reads the leaner of the two sides of the exhaust. If all of a sudden on side leaned out, it will automatically read the lean side instantly and that LED would turn on. But it will have the other modes so it will read the richer of the two, or each side individually.

Jason

[microsuck]

Andrew,

You said you did yours with a manual switch?

If I build it like I want to, It will be dynamic. I figure I would pretty much use it mainly in the mode where it reads the leaner of the two sides of the exhaust. If all of a sudden on side leaned out, it will automatically read the lean side instantly and that LED would turn on. But it will have the other modes so it will read the richer of the two, or each side individually.

Jasoni just did mine that way because I wanted to view two different things on one gauge. I switch it manually. but most of the time its set for the incoming fluid (the colder one). my bike is setup the same way but it has 3 positions, incoming, outgoing, and the difference. it tells you how many degrees it is cooling it. sounds like you are going to have to do some programming for what you want to do.
Andrew

[SILVER2000SVT]

i just did mine that way because I wanted to view two different things on one gauge. I switch it manually. but most of the time its set for the incoming fluid (the colder one). my bike is setup the same way but it has 3 positions, incoming, outgoing, and the difference. it tells you how many degrees it is cooling it. sounds like you are going to have to do some programming for what you want to do.
Andrew
I'm hoping to do it with a small hand full of integrated circuits. So far it looks like I'm going to be able to make that happen, but if it starts to get too complicated I might consider a programmable circuit.

That 3rd position on your bike probably has a small chip to subtract the two voltages?

Jason

[microsuck]

I'm hoping to do it with a small hand full of integrated circuits. So far it looks like I'm going to be able to make that happen, but if it starts to get too complicated I might consider a programmable circuit.

That 3rd position on your bike probably has a small chip to subtract the two voltages?

Jasonthat would be my guess. it takes the difference between the two probes

[min150mph]

I've got a toggle switch on mine to go between left and right bank. I guess to show the leanest one in one mode etc. is a good idea, but i'd like to know which one it was from too and in general I've never seen a big difference between left and right bank and I've got the WOT calibrated gauge.

[SILVER2000SVT]

I've got a toggle switch on mine to go between left and right bank. I guess to show the leanest one in one mode etc. is a good idea, but i'd like to know which one it was from too and in general I've never seen a big difference between left and right bank and I've got the WOT calibrated gauge.
To know which one it is, it will light up 1 of the 2 LEDs corrosonding to which one is giving the leaner mixture, or just switch to either side to and compare the two manually.

The point of doing this probably doesn't help you from day to day, but on the rare occasion that something screws up and causes a lean out condition you know it immediately and don't have a 50/50 chance that you just happen to have your gage on the side that leaned out.

Jason

[microsuck]

but of course none of this even matters unless you are using a wideband 02 sensor and corresponding controler.

[SILVER2000SVT]

but of course none of this even matters unless you are using a wideband 02 sensor and corresponding controler.
Ok, I admit, I haven't completely done all my research on the sensors themselves, because I didn't think it was that critical to getting the circuit to work.

Are you saying the air-fuel gage don't work with the stock O2 sensors and they need to be changed out to a wide band?

What is the voltage range of these? (Right now I'm going under the assumption of 1-5volts, but that's really just a guess.)

What is the controller for a wideband used for?

Thanks,
Jason

[microsuck]

any sensor other than a wideband will read only "lean" or "Rich". lean being all numbers over 14.7 and rich being all numbers under 14.7. 14.7 being the desired crusing AFR. the computer dosent even read from the 02 sensors once you start getting up on it. it goes from a pre programed data set in the computer. Now a wideband is something useful, you can actually see what your AFR is, not just read random voltages from your stock sensors to a little flashey light gauge. but I do admit, that would be a nice piece of eye candy. if you want something that will save your ass when it comes to lean and rich conditions, get an EGT, exhaust gas temp gauge.

[microsuck]

What is the voltage range of these? (Right now I'm going under the assumption of 1-5volts, but that's really just a guess.)


Thanks,
Jasonthe operating voltave is 0.0 - .99 volts

[SILVER2000SVT]

the operating voltave is 0.0 - .99 volts
Andrew,

Thanks for the info!

From what you are saying I assume that anyone adding an air fuel gage has to change out their O2's to a wide band, if they want to read correctly at WOT?

Do the wideband sensors also function correctly for what the computers using them for?

I would like to do the same thing for a pyrometer as you suggested, but that is really going to be a challenge, because they use thermocouples which work off of millionths of a volt. The signal has to go through an amplifer before they can be read or used for any circuit like I'm trying to do. If I were to do that, (amplify each signal then send it to my comparator circuit) then I have an amplified signal to send to a gage that is designed for a non-amplified signal. For the gage the read correctly I would then have to divide the signal by the amount I amplified it. I don't think that the signal would be very accurate after all that manipulation. It might can be done but not very easily.

Jason

[microsuck]

Andrew,

Thanks for the info!

From what you are saying I assume that anyone adding an air fuel gage has to change out their O2's to a wide band, if they want to read correctly at WOT?

Do the wideband sensors also function correctly for what the computers using them for?

Jasonwell, to get a 100% accureate reading, yes. but no one does. the stock sensors will give out a voltage, but what I am saying is that the computer only uses that voltage when you are crusing. You can read from that voltage on an AFR gauge, but it isnt accurate, for the same reason that the computer dosent use the sensors for anything other than crusing. there is so much airflow and the sensors are fairly inacurate, due to the fact that they dont have to be accurate because the vehicle dosent use them. If it was using the 02 sensors at WOT, we wouldent need to get chips to adj the AFR, it would do it on its own. My friend with a turbo 5.0 built a computer for his wideband sensor and controler and he can read his exact AFR to the 10th of a point and he can specify a target AFR under WOT with his box and his box will modify the MAF voltage to regulate the AFR. now thats cool. he is building and programming one for me too. he had to code the whole thing in assembly. it wouldnet work with stock sensors because they dont give an accurate reading, the esentially only read rich or lean.