CARB DATA LOGGING with ECU PROJECT

I have a lot of questions for this project.

I have a 71 nova that i basically swapped a 89 5.7 TBI (LO5) motor in that i rebuilt along with a carb, intake, cam, headers and exhaust. i know i dont need to run a ecu with a carb but my end goal to be able to data log rpm, vacuum and o2. i already have a innovate lc1 wideband installed but with out rpm and vac i cant tell what system to tune, and i dont want to buy the 200 dollar thing innovate sells to log rpm and vac. oh and i want to hook up the knock sensor to detect detonation.

So my idea is to get an ECU (not sure which on yet) and hook up just the wires to the ecu needed to log rpm, vac and o2 in tunerpro rt. i read somewhere that you can hook innovates lc1 to the stock ecu so tunerpro rt can log it.

First question: do i need to get the ecu that came with my motor (1227747) or will any of them work? i just want to make sure all ECUs output the same signal so i dont get the wrong readings (knock sensor).

Next, will tunerpro rt datalog rpm, vac and o2 from the ecu if there is no chip installed? will it also log if not everything is hooked up to the ECU? i.e. fuel pressure, ignition and other useless stuff i dont have?

or better yet does anyone know a cheap way to data log rpm, vac, o2 on your computer?

i am completely new to playing with ECUs but i am good with wiring so im not to scared to try it, any and all help is greatly appreciated

Thanks, Nathan

Wow, it would have been easy if you left the motor in tact as a TBI system.

I did use an ECM once to log the stock narrow band reading just because I was bored and was told it can't be done. But you can't get RPM without the EFI distributor hooked up, not sure about MAP or knock and no way to get WB into a 1227747 ECM data stream.

Quote:

---

Originally Posted by EagleMark

Wow, it would have been easy if you left the motor in tact as a TBI system.

I did use an ECM once to log the stock narrow band reading just because I was bored and was told it can't be done. But you can't get RPM without the EFI distributor hooked up, not sure about MAP or knock and no way to get WB into a 1227747 ECM data stream.

---

RPM signal can be taken straight from the tach signal at the distributor or the tach output of a msd box.

Need a tach filter for signal from a old carb HEI distributor, which is what the MSD 6 box has and works for EFI conversion.

You could do this, but you'll be farther ahead to spend the $200 on the innovate piece, unless you ever plan to actually inject your engine. When I had my Innovate WBO2 sensors I had considered getting a couple of the add on items for logging, but never did because most of them would have been redundant to what I could log through the ALDL data stream of my ECM.

Alternatively, there are WBO2 sensor systems on the market that will log everything you said, or most things. I had a PLX WBO2 system that would log everything, including the knock, though the knock input was odd.

14point7.com has the WBO2 systems I prefer, I know the SLC_DIY2 and SLC_PP2 will log RPM, along with other sensors that you define, and could likely log knock, if you used one of the early EST systems that used an external knock module. I'd have to look at what the actual signal was that was fed to the ECM, whether it was just a simple varied voltage or if it was a pulse train. Either way, I'm sure it could be used that. There is also the iDash that sends information to a smart phone, that has many inputs and the option for 1 or 2 lambda sensors.

Other WBO2 systems can have similar features.

To use an ECM to do this, will still cost you some money to set up right, and IMO gain next to nothing.

To log RPM, there's a circuit that you would need to build to interface with the coil negative, but I haven't been able to find the details on that circuit in a while.

Manifold pressure is pretty straight forward, as well as coolant temp.

WBO2 will depend on which ECM you actually choose and could use other inputs that are not being used, such as EGR position, if the ECM has it, and then edit teh ADX file to display AFR correctly.

No, the ECM will not log data without a chip or MEMCAL installed. The chip or chip contained on teh MEMCAL hold the code that defines how the inputs and outputs are defined and then how the items are reported to the ALDL connection.

I would not recommend the '7747 to do this, since the logging rate is very slow (160 baud), other ECMs, such as the '7730, '7427, '7727, and numerous others have a much faster logging speed at 8192 baud, that will make the data gathered for tuning much more useful.

Really to do this with an ECM will require a pretty in depth knowledge of the ECM and the software associated with logging and tuning of the ECM. You may need to edit a bin file to get certain things to show up in the datalogging stream, though there should be ways around that.

To connect your laptop to the ECM you will need an ALDL cable that will cost you between $45 and $80, unless you can build one yourself. You'll need the ECM, which if you don't already have it will usually be between $25 and $50 at a local wrecking yard, then additional parts to support the sensors and systems you want to log, say between $20 and $40 for the items used from the wreckers, then add in the custom circuit that you need to log RPM, which will be between $5 and $30 depending on whether you build it yoruself or have someone build it for you. I recall that the circuit was pretty simple. Say between $20 and $50 for wiring harness and connectors.

So we are looking at between $120 to $250 as a guestimate in how much it will cost to log data through an ECM, and we haven't accounted for the time figuring out how to make it work yet. That Innovate piece looks to be pretty reasonable now.

Even getting many of these items for free or cheaper will still leave you with a bunch of parts that may not work out how you want.

Now if you are planning to eventually inject your engine, then that changes things entirely, and the parts would be worth purchasing now.

i run a lot of carb equipped vehicles for speedway on the delco and use it for full spark control comes in handy but the rules stop me from being able to datalog on track.its pretty easy to set them up for just spark and logging with minimal sensors

If you are going to stay carb'ed I would go ahead and buy the RPM adapter from Innovate. The simplicity of it makes it worth the money. I used one to dial in my AFB before I went TBI. All I used were MAP, RPM and WBO2, and got it running great. The only part that took some time was getting a 5V reference for the MAP, but you could use any old cell phone car adapter that puts our 5V.

I plan on keeping my crab for awhile and i repriced out what innovate sells them for and they have come down a lot since i looked at them last, i can get an ssi-4 (log 4 channels) for 130.00 so thats not bad. think im just going to get the ssi-4 and then i can log everything together.