Ok.. been playing withthe SGI-5 trying to get it to work..
I need to get my math straight though.
I have:
89TA VSS, ( I think 4000ppm)
3.73 gears

Tunercat has told me that 245-50-16 tires = 812 rev/mile ..

What do I set the pulse/driveshaft rev to in tunercat?
and what is the output to the 89 speedo? 4000 or 2000ppm?

I worked all that out to 1.32pulse/driveshaft rev.
4000ppm / (812rev*3.73)=1.32


I'm close.. I can feel it..

I should be able to remove the stock buffer box altogether right?

 

got speedo to read 80km when it should read 60.. computer still doesn't read anything.. i have switch 1-3 off and 4 on.. I have computer in the #1 output and speedo in #4 which is
#1-8000ppm AC #4-4000ppm OC .. i dunno what im doing wrong.. half the trouble is understanding the instructions... green light blinks 16times too.. still unsure what that truely means..


link to the manual is here..
http://www.dakotadigital.com/manuals/SGI-5B.pdf

 

i'll get this yet by myself.. .. got speedo to work off sgi-5 .. at correct speed.. looks like pcm speed is dam close... so i may have it.. will tweak around a bit then let you know what i did..

 

Wish I could help man....I never had to go through this trouble because I have a T-56...Sorry

 

im getting through it.. i found out that you have to eliminate the buffer box altogether.. it was 1/2 the problem..

 

whats up thirim
hey man if you get that down let me know how you did it. pics,step by step anything. that is next on my list after i find out why my car bogs down when i give it gas.

 

ok.. here it is..

Step 1 .. use tunercat, enter your tire size and rear gear.
take 8000ppm / (# tire rev / mile)*rear gear
ie 8000/812*3.73 for 245-50-16 tire and 373's
you get 2.64.. reason for 8000ppm is that the sgi-5 will output 8000 on the settings I used..
take the 2.64 or whatever and put it in tunercat as your pulses per driveshaft rev.

Step 2 is to take a couple readings of your speedo-vs-tach. I tached 2000rpm at 60km/h in 4th.. so i used that.. I took 3 readings altogether..

Step3
I wired it up with the dip switches on SGI-5 1-2-3 OFF and 4 ON.
jacked up the rear wheels and let her rip.. I had to adjust the sgi-5 down to match my recorded speeds..



I had a buffer box so I had some convenient connectors in which to splice off..

SGI-5
PWR -- a switched 12V
GND -- splice to the PPL wire from the VSS along with the PPL from the ECM

SIG IN - Splice to Yellow from VSS

OUT1 - Splice to YEL from ECM
OUT3 - Splice to Speedo wire.

need more lemmie know.

 

This is sweet Thirim, I have the same tire size and gears, so whatever you do to get it to read properly in the PCM (don't have an electronic speedo, but that comes later) then I wanna know this is sweet stuff man keep up the goods.

 

Now that the PCM is seeing the car's speed, I find that it isn't running quite right.. Hard to explain but every once and a while it will seem to miss, hard.. My first thoughts are that the computer is used to the way the car was running.. and I will have to disconnect battery for a couple hours, to reset it.. Does this work, or is it myth? Don't get me wrong the PCM seeing the speed is good, now I have a rev limiter and top speed limiter and fan control..

 

Any update ?

 

Would this equation work if you used the 4000ppm AC output or Out#3 on the SGI-5 box? with all switches off?

4000/(812*3.73) = 1.299 or 1.32

in which case the PCM would be tuned to see 1.3 Pulse/Driveshaft Rev?

or better to run the 8000/(821*3.73) = 2.64

which PPM is better to use, higher because it's closer and more accurate?

 

the only reason i set to 2.64 is because i read that the pcm can only read 5pp drive rev and above.. so i got it to go as high as I could.. sure.. try 1.32 .. dunno if it works.. no logic other then my first try was the 2.64 and it worked.. I never dropped the power yet.. I must do that now that you reminded me..