I have done some searching and was curious if any of you guys have figured out what sensor wire would be best to splice into in order to record a/f? I know it would have to be converted, but I wasn't sure if anyone had the tables to convert or has gotten this all figured out. I'm thinking about tuning my car, but I need some way to log the data. I saw there are 5 and 6 channel wideband setups out there that read all of the necessary sensors, but I didn't know how they would be hooked up. Do you just splice into the wires for that sensor and log from the wideband setup? Any help would be appreciated.

 

Are you are talking about recording a signal from a narrowband sensor into a wideband logger? Won't be accurate or useful beyond what you see in datamaster or any other logger. If you get a wideband sensor, some systems can simulate the narrowband output switching to get the PCM the signal it is looking for - this is if you put the wideband in the bung where the stock narrowband was. As far as the other sensors go, that will work as long as the input impedance of the interface is high enough to not load down the signal. So you can use pigtails or splice into wires to do RPM, MAP, TPS, etc. if your measurement circuit doesn't interfere with the data from the sender - most of them are OK in this regard.

 

Or are you looking for a place in the stock PCM to log the signal from a wideband controller like the LM-1? Here's a post that suggests using the A/C pressure sensor input to the PCM, and offers a spreadsheet that converts the signal to A/F ratio:

http://camaross.com/forums/showthread.php?t=460884

There was also a post maybe a week or two ago asking where you could log a wideband. I suggested figuring out what PCM pin the Corvette used for oil temperature, since the F-Body PCM scanners will log oil temperature, even though there's no sensor hooked up to the PCM (reads -40deg = open circuit).

The typical wideband controller allows you to set A/F values for the 0-5V signal output range of the controllers, and puts out a linear A/F vs V signal between those limits.

 

Not recording the narrow band sensor into the wideband logger. I just want to know how you guys use a wideband O2 setup and log the car with all of the other sensors displaying in the log. I guess that would have been a better question.

I've read both of those threads (before I posted). I still have the AC, for now, so I was looking for something else. I don't understand the whole "adding a pin" concept for the oil temperature wire. I understand everything else, just not how you're supposed to get that signal to log.

 

I'm not suggesting "adding a pin". I'm saying that the Corvette PCM and the F-Body PCM seem to be similar. The Corvette PCM includes an input for an oil temperature sensor. The F-Body does not have a sensor, but it may have the pin on the PCM, since the F-Body PCM outputs an ol temperature value as part of the data stream. You wouldn't be adding a pin to the PCM, you would be adding a wire to the connector that corresponded to the oil temp input pin on the Corvette.

 

The problem with temperature inputs is that the PCM has a voltage divider circuit in place. You can't just input 0-5 volts.

Pressure inputs are ready for a direct voltage. I used the A/C pressure input because it's easy to get to and it's also something that is not necessary for engine operation. I only need to log WBO2 data when tuning so not having the A/C running for those periods of time is no big deal. When I'm done I just hook it back up and things are back to normal.

I've wanted to use the extra pin that on Corvettes monitored the third O2 sensor. I had someone do some testing and it appeared to him that the values are not updated in the scanning software, no matter what voltage is fed into that pin. I'm guessing the PCM software needs to be hacked in order to get that to work on f-bodies

 

I get what you're saying now. So, the AC pressure is the best place to splice into. I guess you unhook the plug and just splice the wideband controller into it? Did you get an AC female plug and splice that onto the wire that comes from the wideband controller box? I'm sorry if I'm not understanding, just trying to get an idea of what I would have to do if I bought a wideband setup. I really do appreciate the help guys.

 

I know with the LM1 you can buy an add on box that expands its capabilities. It has additional inputs. If you wanted to make things easy and spend the extra money all you need to do is buy the wideband O2 setup, the additional logging hardware, and an inductive ignition pickup (just clips to the spark plug wire). This will allow you to record AFR and the corresponding RPM and be able to replay this information using Innovate's software that comes with the equipment.

I was too cheap/broke to buy the extra hardware so all I have is the LM1 wideband O2 controller and a sensor. I made a wiring harness that does two things; 1.) output a signal that emulates the stock narrowband O2 sensor, this allowed me to run the wideband without having to weld in a seperate bung, 2.) a signal to the A/C pressure wiring harness.

I don't have a weatherpack connector for the A/C harness because I've only done limited testing at this point and don't want to invest in something unless it works. I just stuck a couple pins in the connector and wire tied them back. I was able use Datamaster to record everything, including the changing A/C pressure. The trouble then was making sense of the A/C pressure reading, which is why I've created this spreadsheet. I haven't proved the effectiveness of the spreadsheet because I lack the time. If it does work as planned than extra equipment is not needed and time to tune WOT will be greatly reduced (it also does the math to tell you what PE numbers to use in your flashfile).

That's where I am right now

 

I read that about you designing a spreadsheet to do that stuff in another thread. That's pretty cool. I wish I could test it out for you, but I don't have the stuff to do it. How would you prove the effectiveness of the program? Drive once and log the run and then unhook everything and try to duplicate the run reading the true a/f? Then see if the values are coming out close? Do you have a set value that you try to reach in the program that calculates the values for the PE tables? I figured with a program like that you would need a set value (for each cell) that you are trying to reach. Sounds neat.

 

I would prove the effectiveness by making several tuning runs until I was satisfied with the WOT AFR throughout the rev range, according to the spreadsheet. I would then compare it to the wideband's display by having someone mash the throttle while I watched the display. Simple as that. I'm using some equations that are not verified so I can't gaurantee it's accurate. I've also tried to forsee any problems and account for them but you don't know for sure until you start using something.

As for the tuning section of the spreadsheet, yes I enter the target AFR. It takes all RPM and A/C pressure readings, averages the A/C pressures for each RPM tuning point, finds the corresponding voltage from that A/C pressure, calculates the corresponding AFR (depending on inputs the user gives it for wideband settings), and also displays statistical data (median, min, max, and range) to help give an idea of the accuracy and uncertainty. It graphs the AFR vs. RPM to give a nice visual representation. The average AFR data is then imported to the tuning section where you enter the desired AFR and your current flashfile's PE settings. It in turn gives you new PE settings to try in the PCM to attain the desired AFR at each RPM point. Looks nice, sounds nice, but is totally untested. I have some data in it but only for demonstration as I collected it a long time ago and haven't verified it.

If I can prove to myself that this works than it could save people like you some money and possibly tuning time as well.

 

My setup runs separate from the PCM and it's a pain because I have to run two softwares simultaneously, but it works. For wideband, I have a DIY/Techedge setup which I built from a kit for cheap - they give you everything, but you better know how to solder - not a beginner kit (or they have finished, tested kits as well). Inexpensive, and it has wideband, 0-5v output, narrowband simulation, 3 aux inputs besides rpm (boost, water injection, whatever), and 3 TC inputs for temps and an onboard logger if you don't want to hook up to a pc. Then I also run Datamaster or PCM Log as well. It's not ideal, but you get a lot of data that way. I also have a Innovate LC1 gauge which I need to still hookup, but I'm trying to find a way to build it into a 2 5/8" Autometer gauge housing and stick it in my 3rd middle AC eyeball vent next to the FP & Boost gauges. Gotta get busy & get er done.

 

How come there is no way to splice into the aldl cable and run the a/f values into the computer like that? That way you could log everything in Datamaster or Freescan. I don't remember if they have a/f columns, but I would think that someone could patch the program to make this happen. There is someone on here (Matchstick or something like that) that makes patches and can do a lot of different things with the coding of Freescan. If he could add that column and get it to recognize that signal, wouldn't it be possible to log the a/f along with all of the other pcm signals?

 

You would have to feed it into the PCM and monitor the address. You can't just splice into serial data with analog data and puke it out into Datamaster. You might be able to input one or two signals on unused pins, but I am looking at more data than just that. Stock PCM has its limits.

 

The Lm-1 with the inductive picup is just aswome, My dad has it and the software takes all the guessing out of tunning, You can record map, tps, afr, and rpm and more if you want. Now the thing that is so sweeet! about it is that it will record an hour of driving and you can pick out any cell you want any map, rpm and tps and it will tell you how many times it was in a certain cell and the average or high and low afr of that certain cell, so all you have to do is figure out what percentage off a certain cell is and multiply or divide the fuel in or out. Major time savor and way more accurate since it could record a single cell thousands of times.

 

How much is the LM-1 with the inductive pickup?