wired up the sgi-5c went for a drive and when my gps is reading 30, the speedo is reading 40 or a lil over. at 60, the speedo reads 80. tried to hit the down button on the sgi-5c while driving, didnt do anything. the way i have it wired up is: the purple wire coming from tranny sensor is going into sensor ground. yellow wire from sensor is goin into input. for the outputs, i have the purple wire from the vss buffer going into out3 and the yellow wire on the vss buffer going to
out4. there is no ecm either, i converted to a carb. Does anyone have any insight on how i could fix this?

 

I had to play with the dip switches a bit on mine but one tip about the up and dn buttons is you much hold them and they adjust VERY SLOOOWLY. So you may think they are doing nothing but they are just slowly.

 

Based on what you've posted, you haven't gone into all the options of adjustment in the manual.
http://www.dakotadigital.com/pdf/sgi-5c.pdf

The "application" used (described in the manual) is effectively a coarse adjustment of some outputs via the dip switch(es.) Your outs you're using sound fine though. The up/down have available a secondary coarse adjustment - RTFM for how to do that. Like said, the fine is slow. But you might need to change a dip switch. Depends.

 

Heya grove. Nice combo you got there listed in your sig. VERY similar to my setup except i have the 2.02 aluminum trick flo but you have a tiny bit bigger cam. Everything else looks the same as what i am running 'my bottom end is all forged & 4 bolt main though'... VERY NICE!!!

Anyway so i am just now doing my t56 swap and using the same rear end gear as you. So being lazy to calcute and seeing this post i thought i would ask, What color gear are you using for the speedo sensor and, once you figure out the SGI-5c can you let me know what settings you used on the switches. Thanks!

 

thanks jupiter. when i figure this thing out, ill post it. as far as the gear color. i didnt change out any gear in the trans. with the sgi box you shouldnt have to change out gears.