boostedmaxPSI

I recently swapped out my 4+3 for the Keisler TKO600. In doing so it seems the most trivial part of this install was around the VSS and getting the SGI-5 C settings set for my application.

Here are my findings documented for future reference.

Dakota Digital SGI-5 C settings for 1988 Corvette
After splicing in series the SGI-5 C to the VSS signal input (Yellow wire (K) on C237) the input from the VSS on goes to the Input Sig on the SGI-5 C and OUT 3 goes to the cut yellow wire going into the digital dash.
I followed the directions in the Keisler book with the dip switch settings and that didn’t work for me.
I needed:

1 off
2 on
3 on
4 on

Course setting was between 5-7 and fine setting was 8. This assumes 26” tire and 3.07:1 gears. With these settings I’m roughly .4 miles per hour off compared to my GPS.

0American Powertrain

So your off .4 miles an hour? Or 40 %?

LD85

from the search engine

Blue from tranny, brown to dash

boostedmaxPSI

This should be more clear. As an example, speaking about today only after the adjustments made with no additional fine adjustments.

If my speedometer registers 30MPH my GPS indicates 30.4MPH. I think that's pretty spot on.

I have yet to take it out on the Interstate and set the cruise, it could be spot on.

Hope that adds some clarity.

boostedmaxPSI

Thanks LD85, just wanted to thank you for the PM support on my questions as well.

Just a quick note about the picture above. The 84-86 cars the VSS goes the ECM first then the dash. The 87/88 cars the VSS goes directly to the dash then the ECM.

So, I think in the case of my '88 I will be slightly different.

br

LD85

That is good to know about the different years, , it seems like people struggle with the Dakota Digital setup, and mine hooked up great from the get go,

How a re you liking the TKO ?

boostedmaxPSI

After searching old threads I couldn't really find one that was specific to the '87-'88 cars hence the reason for this thread. Hopefully it helps someone in the future.

As for the TKO600. The kit was pretty complete and fairly painless to get installed.

Light years better then the DNE 4+3 that was in it but not quite as good as the ZF6 in my other Callaway. I hope this is due to it being new and tight still. Seems to be a touch notchy still with less then 100miles on it. I'm sure during the break in period it will shift better.

I'm not a big fan of that shifter that comes with the kit. I will most likly take it to a machine shop and have it milled down another inch or so. Simply too much shifter sticking out of the console.

cgantner5150

FWIW on the early 86 the VSS feeds the dash and the dash feeds the ECM. Removed the cluster and it set a code for no VSS signal.

LD85

I cut my shifter off at the bottom with a hack saw, then drilled two new mount holes to make it the same height as my old ZF Hurst sort shifter

87bob

Do you know what the offset to the left and backset is on the Tremec?

boostedmaxPSI

The kit from Keisler was already pre-configured for my application.

dclafleur

Interesting, I wonder which way it goes on my '85. My understanding was that I could pull the factory ECM and run a completely different ECM and it wouldn't affect dash functions besides MPG

ch@0s

Interesting.. On the 91 the VSS feeds into the PCM then to BCM and cluster via 2 different wires. I will probably be ordering one of these for my LS swap. Thanks for the info.

Waspination

Was curious if OP got this working. I got the SGI-5 and I'm trying to hook this up with the 87 dash with a 95 PCM and the 95 ZF6. My rear gears are also different.

Since these years were both run differently... I'm lost on how to get this hooked up.

LD85

the wire from the tranny gets cut and then one end goes into the SGI per the pic and the other end comes off the SGI per the pic

The ECU makes no diff

93VettePilot

I did a write up on setting this up for my 93 Corvette and 4.10 gears.

write up

There is a power and ground. Then there is finding the right location to wire it into VSS wiring coming from the transmission. I made a little 4 wire harness and soldered it in under the passenger side dash.

Waspination

How would it not? The computer handles the speed sensor differently than my 87 computer.


I read ur write up. Is this green/white wire coming from your PCM as VSS out? And your dash takes that VSS Out into one of its pins. My 87 took two "VSS in" ports straight from the VSS in the Tranny. So Would I have to take the output from the SGI-5 and split the wire to meet both VSS In's on my dash?

LD85

does the zf speedo wire go to the dash?

On my 85 one wire went to the dash, then the dash fed the ecu with another separate wire

There is info to the dash and info to the ecu, all that matters is the dash readout.... unless you are trying to feed info to the ecu

Waspination

In a 95 vette, the Zf speedo goes to the PCM first (signal and ground wire), then from PCM it was supposed to go to the dash with one wire.
I have the 95 powertrain but the 87 body and dash, which before the 87 had two wires fed from the VSS in the 87 powertrain, then one went to the 87 ECM.

I can only get one wire from the SGI-5 for output. I need two for the dash and one for the PCM... or two with the ground. ????

Here my thread I started that shows diagrams of what I'm working with
http://forums.corvetteforum.com/c4-t...gnal-help.html

LD85

can you "T" off the wire going to the PCM and go to the SGI, then out of the SGI to the dash?

Just a thought, sorry I cant help more