GeneralDisorder

iTrader: (1)

*EDIT* - this setup can causes speedometer "jumping" when not in motion. See post #3 for the fix.

Just finished installing the SGI-5E on my 86 Trans Am. I changed my gearing from 2.77 to 3.70 and rather than run down discontinued speedo gears this seemed the better option - also can handle any future changes I might make.

Installation is very simple. I reviewed the diagram and component location - the sensor feeds directly into a VSS buffer (yellow module) on the ECM bracket. I used some double sided tape to attach the calibration unit to the ECM bracket.

Wiring is very easy. Tapped into power (pink w/black) and ground (black w/white) wires for the VSS buffer module. Signal is purple. Cut that and splice into the sensor input and OUT1 of the dakota unit.

It was factory set to the correct (L-L) filter setting. I pulled up a GPS speedometer app on my phone and drove constant speed on the freeway while adjusting the + and - buttons till my speedo matched the GPS readings. All in it took about half an hour to do the install and adjust.

JdubRS

Nice. I need to do the same thing.

GeneralDisorder

iTrader: (1)

A little update to this in case anyone wishes to follow my guidelines for wiring the SGI-5E.

I had random speedometer "jumping" behavior with this setup with the car not moving (worked fine when in motion). I rewired the SGI-5E box to perform all the functions of the buffer box and simply deleted it entirely. On the Low-Low setting I have the VSS signal and ground going straight into the SGI-5, then the 4k ppm OC output (OUT2) feeding the green/black gauge cluster input, and the 2k ppm OC output (OUT4) feeding the ECM and the cruise control. Since making these changes I no longer experience the jumping speedo and everything is getting a clean, accurate VSS signal.

GD

230 firebird

Did you have any problems getting speedometer to show miles?I did the same thing but I called Dakota Digital and I have mine set up from high to low.I have sensor wires going into box and I am using OUTPUT 3 to green wire,but my speedometer willnot add miles or trip odometer does not work.

SuperRamFormula

iTrader: (1)

Thanks for the info. I'm going to install the SGI-100BT on my 87' Formula. I just made the switch from 700r4 to T-56 and my old Cyberdyne speedo calibration unit can't handle it. I looked for the SGI-5 but only found 1 and it was on ebay. The Dakota Digital Tech line recommended the SGI-100BT. I was still using the buffer box but will probably remove it now.

Thx,
Tom O.

John in RI

iTrader: (167)

I also removed the factory VSS buffer and replaced it with the DD SGI signal converter & my digital Speedo still says I'm rolling ( speed displayed ) when I'm sitting still. It works fine and is accurate when driving. I've heard that using 2 wires twisted together from the Electric Speedo Sending Unit to the Buffer *might* help correct this, but have yet to try to re-wire it.

I'm hoping to find a pair of twisted wires with a ground shield ( similar to Thirdgen BOSE speaker wiring ) in the junkyard and once found, I'll used that to re-wire the tranny Speed Sensor. Car has a T56, & the DD SGI box feeding the factory digital Speedo and an aftermarket 'performance' digital Speedo. ( not feeding ECM or Cruise )

BluFBdy

iTrader: (1)

did you ever get a resolution to this john? I'm having the same issue with the sgi100bt, I'm showing speed sitting still and the ecm is seeing spikes if I blip the throttle sitting still. I've twisted the vss wires and reduced EMI as much as possible but no luck so far and tech support isnt exactly stellar. Rolling it is right on the money but the output of the box is erratic when parked which is irritating to say the least

John in RI

iTrader: (167)

Nope,.....

I was hoping to come across a nice tight set of twisted pair wires with a ground shield,.... but haven't found one yet so I haven't tried it yet.!

BluFBdy

iTrader: (1)

I'm considering taping my twisted pair from the vss with shielding tape. Another option I'm going to try is using the 2k (out5) square signal and running it to pin c6 of the 7730, this is by far the most frustrating thing I've dealt with so far

Bill91z28

Thanks for sharing but my 91 z28 does not have that yellow box and I am nervous about cutting th wrong wire does anyone know where I should start this is a pic of what I have

BluFBdy

iTrader: (1)

My case and solution was a bit different than others, what transmission are you working with?

Bill91z28

I have a t-5 5speed

BluFBdy

iTrader: (1)

Does it have the electric sending unit or are you trying to adapt a cable sender

BluFBdy

iTrader: (1)

I managed to get it fixed by changing the vss pulse count and running the t56 signal directly into b9 and b10, then splicing a paralell pair of wires off of that and running those up to the sgi box, b11 was cut from the ecm and run to the 4k ppm square wave from the sgi5 and run direct, once I did that the sgi5 quit jumping around, the ecm is reading steady as well. I did the math to determine how many pulses per mile I see with my tire and gear combo then input that into the tune, the ecm is happy and the speedo is steady with no jumping or showing speed sitting still anymore

Bill91z28

i think it’s electronic or at lest that is what everyone is telling me

BluFBdy

iTrader: (1)

if you're using a t5 with the electronic vss it's just a matter of running the purple and yellow wires from the vss on the transmission up to pins b9 and b10 on the ecm so you shouldn't need a sgi for any reason. The t5 electronic vss is a nightmare to find right now, if your t5 is a cable driven sender then you can use an adapter then route it through an sgi box and then into bins b9 and b10. Someone mentioned the 4th gen vss being the same but I'm not sure about that one. Need to know if your t5 has cable or electronic sender to go any further really and I would suggest starting a new thread if it doesnt involve using a dakota box so this one isnt cluttered up

Bill91z28

it is electronic vss purple wire and yellow wire that go from the transmission directly to the ECM

John in RI

iTrader: (167)

The only reasons I can think of to use the SGI with an electric VSS T5 is if the BUffer ( or ECM ) had defective VSS circuits or if the rear end has 3.73 gearing or some other 'odd ball' gear. There is no proper factory combination of speed gears for the T5 with electric sending unit. With a cable - 3.73 speedo gears were available,.. but not with electric.

In the 84-89 cars with electric VSS ( early design ) the signal from the VSS is 4000PPM, goes to the buffer and gets split to the ECM and Cruise @ 2000PPM and to the electric speedo @ 4000PPM.

90-92 TBI cars handle it the same exact way: from the VSS ( late design) is 4000PPM, goes to the buffer and gets split to the ECM and Cruise @ 2000PPM and to the electric speedo @ 4000PPM.

In the 90-92 V6 and TPI the electric VSS ( late design) makes 4000PPM, send it directly to the ECM and the ECM sends it to cruise @ 2000PPM and the Speedo @ 4000PPM.

Bill91z28

yes I have changed the gears from 3:08 to 3:73 and was using the sgi 100 BT to adjust the speedometer

John in RI

iTrader: (167)

While sitting in Neutral today in my garage before a ride to terrorize the town,...............

BluFBdy

iTrader: (1)

Splitting th signal wire was the only thing I could do to get my intellitronix gauges to not freak out, I drove it this weekend and it's still steady no ghost readings now. Somehow between revisions my vss tweak reverted and the ecm was unhappy but the gauge didnt care