T56 conversion and the Speedo
Thread Starter
Burning Brakes
Joined: Jun 2005
Posts: 1,188
Likes: 13
From: Wallingford Vermont
T56 conversion and the Speedo
O.K. I gave up on the 4+3 in my '86 last summer; I could just never get it working right. So I searched for a T5 for a reasonable price. As luck would have it I found a T56 for a "can't refuse" price and snatched it up. So I've amassed all these parts on my floor and I'm getting ready to pull my 4+3 for the last time.
Now I know the speedometer/ECU (2000 Pulse Per Mile) is not going to play nice with VSS from the T56 (LT1 camaro, 4000 PPM). And it seems like the solution is the Dakota Digital SGI-5 Universal Speedometer Signal Interface. http://www.dakotadigital.com/index.c...rod/prd126.htm
I've searched, and a couple CF members said they were having problems with the SGI-5.
Has anyone gotten this to work yet?
What exact problems were you having?
Is there any other options besides Dakota Digital? (I'm not ready to replace my ECU and Dash just yet).
Any info would be greatly appreciated; like where and what you spliced. This part of the T56 conversion seems to be lacking. (Aren't we ready for a T56/T5 Stickie?) I want my baby to roll, SOON!
Now I know the speedometer/ECU (2000 Pulse Per Mile) is not going to play nice with VSS from the T56 (LT1 camaro, 4000 PPM). And it seems like the solution is the Dakota Digital SGI-5 Universal Speedometer Signal Interface. http://www.dakotadigital.com/index.c...rod/prd126.htm
I've searched, and a couple CF members said they were having problems with the SGI-5.
Has anyone gotten this to work yet?
What exact problems were you having?
Is there any other options besides Dakota Digital? (I'm not ready to replace my ECU and Dash just yet).
Any info would be greatly appreciated; like where and what you spliced. This part of the T56 conversion seems to be lacking. (Aren't we ready for a T56/T5 Stickie?) I want my baby to roll, SOON!
Last edited by DanZ51; Jun 5, 2011 at 12:37 PM.
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
Just as a side note, I installed a 4+3 in my chevy truck. I added a manual switch to turn it off and on at will.
I installed a relay from the battery through a fuse, and another relay to turn on and arm the other relay so I can turn off the key and the system is dead.
Now, I just turn it on when I want, and turn it off after I come to a stop. It is fully manual, and I treat it like a 5 speed. In a 5 speed, you have to shift in and out of 5th gear, so I shift in and out of "fifth" at will. Never failed yet after 4 years. I also have overdrive...............Which makes my 54 year old truck keep up with traffic and get gas mileage.
I incorporated the first gear lock-out switch on the first-2nd arm, and it prevents me from forgetting about it and nailing it and shifting into 1st overdrive when I am smoking the tires.
I installed a relay from the battery through a fuse, and another relay to turn on and arm the other relay so I can turn off the key and the system is dead.
Now, I just turn it on when I want, and turn it off after I come to a stop. It is fully manual, and I treat it like a 5 speed. In a 5 speed, you have to shift in and out of 5th gear, so I shift in and out of "fifth" at will. Never failed yet after 4 years. I also have overdrive...............Which makes my 54 year old truck keep up with traffic and get gas mileage.
I incorporated the first gear lock-out switch on the first-2nd arm, and it prevents me from forgetting about it and nailing it and shifting into 1st overdrive when I am smoking the tires.
Last edited by coupeguy2001; Jun 5, 2011 at 08:02 PM.
Thread Starter
Burning Brakes
Joined: Jun 2005
Posts: 1,188
Likes: 13
From: Wallingford Vermont
Well, I've owned my '86 for twenty years as of this May. The 4+3 crapped out years ago, and I had it rebuilt by the only "expert" that would touch it (from NY, certified check only). His work was good but that damn carrier bearing went titsup again. I'm THROUGH with this inferior design! Doug Nash went out of business for a reason, and the 4+3 is either the result or the reflection of their demise. PS. I rebuilt the manual portion about 12 years ago when I changed the oil and half a shim came out. Turns out, I found the other thrust washer installed (FROM THE FACTORY) backwards!
Now please, does anyone have any experience with the Digital Dakota SGI-5?
Now please, does anyone have any experience with the Digital Dakota SGI-5?
Thread Starter
Burning Brakes
Joined: Jun 2005
Posts: 1,188
Likes: 13
From: Wallingford Vermont
Thanks dc, I've read the the manual for the SGI a couple of times myself. I think I got it figured out.
LD, that's exactly what I want to hear!
I guess the problems I heard were just operator error.
Do you remember much of your install? When I finally get to this part of my conversion I'll try to document it for others to follow.
Time to pull the trigger on a few more parts..
LD, that's exactly what I want to hear!
I guess the problems I heard were just operator error. Do you remember much of your install? When I finally get to this part of my conversion I'll try to document it for others to follow.
Time to pull the trigger on a few more parts..
Race Director
Joined: Feb 1999
Posts: 12,772
Likes: 17
From: Indianapolis IN
Thanks dc, I've read the the manual for the SGI a couple of times myself. I think I got it figured out.
LD, that's exactly what I want to hear! I guess the problems I heard were just operator error.
Do you remember much of your install? When I finally get to this part of my conversion I'll try to document it for others to follow.
Time to pull the trigger on a few more parts..
LD, that's exactly what I want to hear!
I guess the problems I heard were just operator error. Do you remember much of your install? When I finally get to this part of my conversion I'll try to document it for others to follow.
Time to pull the trigger on a few more parts..
put the dip switches as shown, drive and calibrate up and or down
Last edited by LD85; Jun 7, 2011 at 11:29 AM.
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Pro
Joined: Feb 2010
Posts: 677
Likes: 3
From: Metairie LA
FWIW and just going from memory, but while looking in my 86 FSM this past weekend, the speedo output is 4000 ppm (86 4+3). I'll check when I get home this afternoon.
I got lucky with my T5 swap - the speedo is dead accurate.
I got lucky with my T5 swap - the speedo is dead accurate.
Burning Brakes
Joined: Sep 2009
Posts: 1,180
Likes: 2
From: Yes it's hot! Arizona
Thread Starter
Burning Brakes
Joined: Jun 2005
Posts: 1,188
Likes: 13
From: Wallingford Vermont
The whole Pulse Per Mile and Pulse Per Drive Shaft Revolution has me kinda confused. I searched the internet and came back with lots of contradictory information
Quote: The T56 sender is a) 40 PPDR, b) 100,000 PPM, c) 4000 PPM I've read all three.I've heard (and believe) the T5 uses the same PPM count sender the 4+3 does. My understanding is the T56 uses a different count, thus needing something like the SGI-5. Guess I need to check the FSM too.
BF, that's the first I've hear about the Abott ERA (learn something new..). How much did they nail you for, beings they don't show a price on their website?
Thread Starter
Burning Brakes
Joined: Jun 2005
Posts: 1,188
Likes: 13
From: Wallingford Vermont
Epilogue
OK I wired up my T56 to the SGI-5 and connected that to my original speedo harness. 'All neatly mounted to what was once my ashtray so I could calibrate it and tuck it out of sight.
At first I couldn't get a speed read out at all. The SGI-5 would blink it's green diode telling me it was receiving a signal. So I PM'd LD85 as I was slightly confused. LD85 stated he used output #4 and , in fact, this compares to the Dakota Digital manual that states "output terminal #4 is for most TPI computers".
But if you look closer to LD85's picture you can see he actually used output #3. For this setting output #3 provides an AC signal (sine wave) as opposed to output #4's OC signal (on/off). LD assured me the picture was correct and it was.
My speedo immediately showed life after the correct output was used. It took me a few minutes to figure out how to calibrate it to my GPS; I still had the forth dip switch "off" which is the low range. Now it's dead on
Bottom line: Dakota's manual needs a little correction, but now you got the lowdown.
At first I couldn't get a speed read out at all. The SGI-5 would blink it's green diode telling me it was receiving a signal. So I PM'd LD85 as I was slightly confused. LD85 stated he used output #4 and , in fact, this compares to the Dakota Digital manual that states "output terminal #4 is for most TPI computers".
But if you look closer to LD85's picture you can see he actually used output #3. For this setting output #3 provides an AC signal (sine wave) as opposed to output #4's OC signal (on/off). LD assured me the picture was correct and it was.
My speedo immediately showed life after the correct output was used. It took me a few minutes to figure out how to calibrate it to my GPS; I still had the forth dip switch "off" which is the low range. Now it's dead on
Bottom line: Dakota's manual needs a little correction, but now you got the lowdown.
Melting Slicks
Joined: Mar 2003
Posts: 2,512
Likes: 49
From: Franklin IN
How much did you have to pay ........
How much did you have to pay for the SGI-5 and where did you get it? I'm not far behind you. Also how did you solve the reverse solenoid lock out. I re-purposed the orginal shifter and am using the overdrive switch to activate a relay for the reverse solenoid.
Last edited by 87bob; Aug 23, 2011 at 02:00 PM.
Thread Starter
Burning Brakes
Joined: Jun 2005
Posts: 1,188
Likes: 13
From: Wallingford Vermont
Sorry I'm a month late, I guess this thread got "run-over". I got the Dakota digital from Summit (IIRC), it wasn't badly priced. For the reverse lock-out I kinda surrendered to "just get it done" mentally, and installed a push button in my console. Yes you gotta reach over with your left hand to hit the button while you shift it into Reverse, but it's not that akward. I thought about a button on the shifter, but the big black Hurst **** was calling me 
