this is gonna be one hell of a first post
i been bugged by this vss not reading correcly after my swap and i think i have figured it out. The question is that older 700r4 use a square wave and ls1 use a sine wave and they cannot work together. well i know that but my results show otherwise i believe.
Backgound
after watching a few videos of me racing and a few friends telling me that it sounds like my car is shutting off for a split second at the 1/8. well after looking closely at the logs, there is a little blip. Well when you swtich from an M6 to and auto the ppr on the vss are different. Well when this doesnt get changed or changed improperly your input speed is off. Well when you look at the logs the vss shows that iam hitting 256 mph in the 1/8. this is where things get shut off. So i changed the ppr from 17 to 40 and though that would fix that. No it doesnt. you have tio change all the catagories in the speedo section of hp tuners.
This is how i was able to use a square wave vss on a 700r4 with a 99 ls1 computer sine wave input, without a dakota digital box.
you will need hptuners, gps, electronic speedo that can display ppr.
1. open scanner in hp tuners and go on a hiway and log speed that the pcm is seeing and what the gps says
2. open up your tune and the speedo section.
3. enter your tire dia and gear ratio, general vss pulses get changed to 80,000 per mile and 40 per rev-trans.
4. final drive ratio- your rear gear, trans rev per mile will automaticly be calculated for now. we will be adjusting this later
5.now you have to force save this, so click file and save. then flash calibration only to your pcm
6. drive and open scanner and compare input speed to gps speed. write these down.
7 find a measured mile, calibrate speedo to standing mile calculations . write down ppr
8. open tune again and speedo. enter on trans rev per mile what your speedo says. test drive and compare gps and scanner speed reading
9 if speed is too low, decrease tranny ppr per mile in trans rev.( 110,000) ppr is 3 mph off with 3.73 and 255516 mt et street. too high increase tran rev ppr per mile in the trans/rev section. click file and save once you are close then flash calibration only.
i spent about three hours today getting this close, i hope this helps someone wanting to do this swap. i attached a scrrn shot of what has to get changed and how in case anyone wants to know. apparently gm pcm have a buffer of some kind built in. cause iam sure with some minor tweaking the input can be adjusted to be dead spot on.

 

You can do it the easy way intead by utilizing a VSS directly compatible with the LSx PCM

Find any 4L60E trans, V6, V8 w/e. Pop the VSS out and grab the connector. Next, pull the tailhousing off (4 bolts nothing terrible) and use a fabricated puller tool to pull the reluctor ring off the output shaft. It's a .002" interference fit so it may take some grunting

Now, Pop your tailhousing off, remove the old VSS stuff and press the new reluctor onto the output shaft. Install the new VSS into the hole in your 700R4 (only works with large VSS housings ie All that came with electric speedos)

Change the conversion factor in the tune for your tire diameter and gearing. Enjoy 100% accurate VSS without any conversion boxes

More info can be found on jagsthatrun. They go into detail about older cable speedos keeping the cable drive and having a PCM friendly VSS on the same trans and offer a multitude of specialty parts for nearly every application

 

yeah i looked into that, wasnt crazy about the price of almost 400 bucks. this only cost me about three hours of my labor. plus no local junk yards with Any 4L60E. New york junkyards suck. they take all the good stuff before it hits the yards