'81 Vette

I know its very old tech now but is anyone using or does anyone have experience connecting up the LC-1 to the SSI-4?
I have the LC-1 hooked up ready to go, just need to get the boss welded into the exhaust. This will be good for reading and logging AFR on the laptop. I also want to log RPMs and see the SSI-4 plus unit can do this.
Wondered if anyone could shed any light on how to connect the SSI-4 to read RPMs and will I need to get an adapter to connect the LC-1 to the SSI-4 or can I simply connect both separately to the laptop? I'll be using the Innovate Logworks 3 software and LM Programmer.

Thanks in advance.

chevymans 77

I have the LM1 with the LM2 connected logging 02, RPM, TP and MAP. I built a 5 volt generator for the sensors and connected the sensor outputs to the LM2 then used the Ser output to the computer from the LM1 for logging with Longwork 3 software.

So I don't have first hand knowledge of the SSI4 but looking at the instructions all the Innovate hardware connects in series with the final piece sending the information to the computer via the ser output.

As far the RPM measurements innovate didn't make that easy. I had issues getting a consistent and reliable indication. I ended up adding a potentiometer to the signal so i could adjust the indication and make it more reliable. There are plenty of articles on the internet about this. The instructions talk to all the different issue's with trying to make an instrument that will work across multiple platforms and that will work with single and multi discharge ignition systems.

Hope this helps.

Neal

'81 Vette

Thanks Neal, I have seen in the instructions about using a potentiometer for the tach signal so I'll see what happens when the SSI unit arrives.

I would be very interested in also logging the throttle position, I wondered about taking an old TPS off a scrap vehicle and seeing if I could rig something up temporarily to enable tuning of the carb.

Once the carb is set, I will remove the LC-1 etc.

DblTrbl

I don't have any experience with the SSI-4 but I do have a little electronics experience and logging experience.

I can see how the speedo potentiometer trick could work, but there is a risk that if the voltage changes, or you set the pot the wrong way, you might fry the SSI-4. You want to make sure the the SSI-4 never sees anything more or less that 0 to 5 volts.

Instead of a potentiometer, I would use a resistor and a zener diode. My opinion is it's safer and more reliable (stable signal). I can draw a diagram if you wish.

Since we're talking old tech, almost 20 years ago I logged data in my car using one of these:
https://www.mccdaq.com/images/photos...rdaq56_500.jpg

'81 Vette

Thanks DblTrbl,
The SSI-4 unit has 5V out to power sensors so that is what I'll try and use for the TPS.
The instructions for the tach are as follows, I'm guessing this is the way to do it?

Attenuating a Tach Signal
The problem of an erratic tach signal happens if there is a lot of ringing at
high voltages. To counteract this, it is sometimes necessary to attenuate the
tach signal by about 30dB or so. This is accomplished with a 100k variable
potentiometer which can be purchased at any electronics store.
1. Connect the tach signal to terminal A.
2. Connect terminal B to the tach signal input on the SSI-4 PLUS.
3. Connect the terminal C to Ground.
1. Turn the pot all the way to the right (until no RPM is registered).
2. Start turning the pot to the left and adjust it to the point where RPM
starts to register. Further adjustments might be necessary to fine
tune the filter.