Dakota Digital SGI-100BT Universal Speedometer and Tachometer Interface

My 5.0 Miata has always had a tach that would jump around and despite tuning an adjustment in the cluster, was never really accurate outside a ~1000rpm range. Purchased this interface hoping it would at least tame the wild tach needle a bit, but was pleasantly surprised that it got my RPMs displaying perfectly on the factory tach. In my case the fiddling I did before made it less simple than setting Input to 8cyl and output to 4cyl, as that setting the tach reading pretty low. Once I switched input and output to both 4cyl and adjusted the fine tuning value, I was able to match the tach to what my ECU was outputting to my laptop.I really liked being able to adjust the unit through Bluetooth, as I will be hiding it behind some plastic trim. The app was quick to download, and it was easy to pair and use. I paid $100 for the interface, and I believe it is worth every penny. Definitely exceeded my expectations.

I have a 90 240sx that I wanted to keep the speedometer and Tachometer working on the stock oem anolog cluster. I have a 2jz that has a r154 first gen transmission. I had to buy analog to digital signal speed sensor from a company called driftmotion to get this to work that goes on the r154 transmission. The app is alright but does the job, you can calibrate the speed using the GPS speed on the app. The Tachometer I was able to take signal from the ignitor chip then fine tune it using the app, cylinder count ect. Worth it if you want to retain oem analog cluster. I've seen these work on ls1 swaps as well.

I have done a Cummins swap in my gasser Ford and needed a tach solution. I cheaped out and bought a digital green display RPM counter that worked well, but as I was finishing the build, I decided I wanted to use my factory tach. I used the Alternator method and this worked great. All you do is tap the lone grey plug on a Ford 3G alternator and use that for the regular Tach input signal. Power and ground of course and finally the Grey with Yellow Stripe wire for the tach output. That can be found in the connector that uses to go to your distributor or in my case (because I cut the harness back) in the bundle of wires where the engine harness connects on the driver's fender well.One word of warning, be careful when hooking the wires up and get it right. It will short out and then you are out of luck. Ask me how I know. Since it was my fault, I just took my lumps and ordered a new one and it worked flawlessly. You will have to play around with the Dakota Digital Accessories app to get it to read properly and you will have to have a mechanism available to read real RPM so you can get this little box to output the right RPM reading. But once done, it is fantastic. I added a 3 amp fuse (probably way too high of a reading for this device) in line on the power and grabbed power from a key-on source in the fuse panel where the engine harness terminates.Good luck. This thing flat out works!

Wiring is pretty straightforward but I had to run a small jumper ground wire from the "ground-" terminal to the "spd-" terminal. "Out 1" provided the modified signal just fine. My photo shows the settings for running 4.11 gears with 275/35R18 rear wheels (Calibration Value 0.84) which made my GPS speed match my Instrument Cluster speed. The bluetooth setup is really easy but I didn't understand all the inputs but what I have showed works great.

I initially wasn't going to buy this cause of the price (too expensive for what it is.) but after other failed converters on the market (not much of them) I broke down and bought this.I bought this for my 2JZ swapped 240sx.It works great for using the speedometer and tachometer.What's extra nice is configuring this via bluetooth using my android phone, works great.But they do offer configuration by the unit too if you don't have a bluetooth phone.I especially like the frequency tester to know if you got everything wired up right.Overall I'm impressed by the quality, just not by the price. I would recommend this to others, but there isn't much choices out there, so it's your only choice sadly.As a random note to others if they are doing a 2JZ-GE 240sx (S14) swap too.My wiring is as follows:Ignition+ to an Ignition 12V source.Ground- to a ground spot on the car.Speed/Input to the output on your 3-wire speed sensor on the transmission.Speed/OUT1 to the R/Y from the back of the gauges (either wire it directly to the gauge or to the plug under the engine bay fuse box, and leave the R wire not attached to anything.)Tach/Input to the 2JZ-GE's Igniter's TAC (pin 4) output.Tach/Norm to the L/B wire (TACHO) that is on the F3 connector that normally would be coming from the factory computer.Now for the software side (via the bluetooth software.)Speed Setup:Input Type: LowPull-Up: OnInput/Output: Low/LowCalibration Value: 2.0Speed Unit: MPHTach Setup:Fuel Type: GasInput Cyl Count: 6Input Type: HighCalibration Value: 1.0Output Cyl Count: 4Output Voltage: 6-18V

The only thing that works for me so far. Speedo finally has signal and my vtec is back!

I purchased this device so that I could get myOEM gauges to work after an engine swap.Part of the reason I purchased this device is the handy app for setup and calibration. When trying to select different options from the drop down menus, it just shows up blank. Have to guess on what you’re selecting and sometimes won’t let you select anything.I contacted Dakota Digital tech support for help with this and wiring for my specific chassis. No help was offered for my wiring.Tech support told me to program the system manually as there may be an issue with the app.Don’t buy this if you were hoping to use the app. I haven’t been able to get my tach to work but I was able to get my Speedo to work with manual methods. Still needs some fine tuning.