Dakota Digital SGI-5 Install

[SlammedDime]

Well I bought one of these instead of an HPP3 since it was much cheaper, and works wonders.

What it does is changes the pulse sent by the VSS on the transmission to what you set, so you can correct your speedometer and odometer for a correct tire size or gear change.

First a list of things you'll need...
The SGI-5 Unit
SGI-5 Instruction sheet
2 Butt Connectors
1 Ring Connector
18 AWG Wire
2 self tapping screws
Wire Cutters
Wire Strippers
Wire Crimper
Drill with screw head attachment
Blade (just in case)
Small Flat Head screwdriver

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Before we even begin, disconnect the negative battery terminal. We don't wanna short anything out.

First thing we have to do, is find a place to locate it. I chose to put it right inside the passenger side kick panel. It is tall enough that it won't interfere with the kick panel once its reinstalled, and this provides and easy point of access for making adjustments.

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First, cut about a 4" piece of wire, and strip about 3/8" of jacketing off each end.

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Attach the ring connector to one of the ends.

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Plug the other end of the small wire into the Ground pinout on the SGI-5 and tighen the screw using the small screw driver.

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Place the SGI-5 up to a spot where you would like to mount it. Take the self taping screws and the drill with the screw head attachment and mount the SGI-5 to the panel. Take the screw towards the front back out, place it through the ring connector, and reattach the screw through the panel. This is what you should have now.

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Now we are going to jump over to the fusebox on the inside of the cab. The SGI-5 needs an ignition power source. In other words, we only want it to turn on while the truck is on. I found that fuse 4, the gauge fuse, only has power when the truck is turned on, so this is what i'll use.

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Take your 18AWG wire you have, and run it from the SGI-5 to the fusebox, routing it however you want to get it there. Strip off about a 1/4" of the jacketing, and stick the wire in the bottom of the two prong holes for the fuse. I'm not sure how much power this thing pulls, so I chose to upgrade the fuse from 10Amps to 15Amps. I haven't had a problem yet, so this seems to be alright. Push the fuse into its spot. It may be a little hard to get in, but once its in, it'll stay there.

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Strip 3/8" of jacketing from the other end of the wire, and plug it into the power port on the SGI-5. Take the screw driver and tighten the screw.

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Now its time to go under the truck to the VSS. Here she is.... what a beauty....

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Unwrap the tape, and pull back the wireloom to reveal the wires. The one we want to work with is the purple w/ white stripe.

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Cut the purple w/ white stripe wire.

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Strip both of the cut ends about 3/8". Then attach a butt connector to each end. As always, give it a small tug afterwards to make sure its crimped well.

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I didn't take pictures of this, cuz I forgot. I drilled a small hole in the firewall right next to where the antenna comes in. Then I took some of my extra 18 AWG speaker wire and ran it through the hole, under the truck, and over to the tranny. Be careful to keep it away from the exhaust components. We don't wanna fry this wire.

Once you run the wire down there, connect it to the butt connectors. I chose to use the silver colored wire as the signal wire, and the copper colored as the return wire.

Once thats all done, take some electrical tape and wrap it up, and re-wireloom it to make it look good.

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Back in the cab, I shortened up the speaker wire to length, and stripped about 3/8" of each of the leads.

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I plugged the silver colored wire into the signal pinout, and the copper colored wire into OUT 1. That is very important. Otherwise it will not work.

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Okay, now that we have it installed, its time to set it up properly.

My SGI-5 came pre programmed so the coarse and fine adjustments were both set at 16. If you look at your settings sheet that is with the instructions, you will notice that 16/16, with switch 4 turned off, equals 1x. That means that as it sits, your speedometer will read stock. If you have a larger tiresize than stock, you will need to turn switch 4 on, and use the following equation to determine what you need to set it at.

Actual Speed
-------------------------------- x Current calibration = New Calibration
Speedometer Reading

I will use mine as an example. I have a smaller than stock tire size, so my actual speed is less than what my speedometer reads. My tire size is 205-60-15. Using this nice little calculator ( http://www.miata.net/garage/tirecalc.html ), I can see that when my speedometer reads 60mph, I am really traveling at 54.6mph.

54.6
------ x 1 (current calibration) = .91
60

My new calibration needs to be .91. I don't see .91 on the list, only .908 and .914. .908 is closest, so I'll use it. This falls under a Coarse setting of 16, and a Fine setting of 3

Following the instructions that come with the SGI-5, i hold down the appropriate button while turning the ignition on, and I can enter the Fine adjustment mode, and I can adjust the Fine calibration until the LED blinks 3 times.


If you are doing a gear change, I have found this little site ( http://pw1.netcom.com/~sgalaba/mph.htm ). You can enter all of your stock information, and then you can enter your modified information, and compare the speeds at a specific RPM to determine what your change is, then you can calibrate it as shown above.