I bought myself a pretty Dakota Digital SGI-5 box.. as per recomendations.. now that i have it .. i have absolutly no idea what to do with it
can someone walk me through it?
start with the dip switch settings. then which of the 2 wires or both, do i hook up ot the thing and from where? I assume from the output going from the buffer box to the speedo gauge?
I have
A31 GND PPL
A32 Signal YEL

I also have the same coloured wires coming from the VSS, so I assume they mean the same thing. Also located wire coming from buffer box, going to speedo, its "C" LT GRN/BLK goes to a connector A14 which leads to speedo.
I have located some power and GND sources for the unit.
But that's all I have.. I have no idea where to go next..
Also note worthy to mention the car was a '89 305TPI T5,
non-digtal dash

thanks

 

anyone?

I have since learned I have to convert a 2000ppm (pulse per mile) 5V DC signal to an AC 17 pulse/driveshaft rev signal.

If tunercat is correct, a 245-50-16 tire = 812 rev/mile . with 3.73 gears, thats 3028.76 drive shaft revolutions. times 17.. =51488.92 pulses per mile .. but it has to be AC..
Currently my VSS is 2000ppm DC ..
I have the sgi-5, but don't know what to do with the switches..

anyone go through this?

 

anyone know what the buffer box does to the vss signal in a 89 TPI car?

 

I was hoping Z28***** would chime in, he seems to be the one who knows this part of the swap. What I do know though, is that TPI cars do not have a buffer box, only TBI cars did. TPI cars had the VSS signal going directly to the ECM, whereas TBI cars had the signal going into the buffer box, then it output the signal to the speedo, ECM, and cruise control module. Becuase of this, I think you would be able to splice the SGI box in between the buffer box and speedo, if you do infact have one.

 

hey texas, long time no talk .. car runs very well, pulls really hard. Hard work paid off big time. Though couldn't have done it without you and pasky and everyone else here.

I do have a yellow buffer box on my tpi car.. I don't know what it does, maybe it isn't a "buffer" box, but it is there. I would be ready to splice it into the output on the buffer box which goes to the speedo, just to see what it does. However i haven't the foggiest on what dip switches to set. Would be alot easier if I had a ociliscope i think, then i could play.. unfortunatly i don't.. probably wouldn't remember how to use it anyway...

 

Doesn't the 89 bird have an electric speedo? My 90 RS has an electric speedo and I hooked the output from the PCM directly to the speedo in the dash and it works perfectly.

 

This isnt what he's trying to do, that part is no problem, he needs to get the correct signal from the vss to the pcm, not the pcm output,

Thirim: what im doing with the next swap im doing which is slowly being pieced together is using autometers 16 pulse / rev sender to feed the SGI -5 , since normally the vss input on them has a ground and a signal, Im not sure just feeding it the one wire output from the buffer will work correctly, seeing as the stock 90-92 sender is a 4 pulse per rev, it made more sense going with the autometer piece to feed it, after doing the math it seems that combined with an sgi 5 and a T56 program in the pcm is about the only way to buffer the signal up enough, since the T56 does 17 pulse per ds rev, the stock vss will do 4000 per mile which is only 1000 rev / mile due to the gear reduction, so by stepping up to the autometer sender you can get around 16,000 pulses per mile, with a 245/50/16 you'll have about 2690 driveshaft rev per mile, with a 17 pulse per rev sensor like the t56, instead of 40 with the auto, the pcm is wanting roughly 45,700 pulses per mile, so you need to step the ratio up from the autometer box about 3x with the SGI5, insert 2nd problem with vss buffer box, it is only used to modify the signal around and split it for the tbi computer and cruise control, as the stock speedometer gets a 4000 pulse / mi signal, the cruise gets a 2000, and i think the tbi gets the same 2000,

Now does this all make sense or have I given you a headache ?

 

makes sense, but dunno if it will work.. I emailed dakota digital, they said the sgi-5 will not do what i want to do.. so i wasted about $120.. and still no further along.. Am I the only one to use a T5 with an LT1?
not sure if the autometer and the dd box will work.. beats putting on a mechanical speed sensor.

 

No you're not the only one using a T-5, I am too. But right now I'm using 2 speed sensors, the stock 3rd gen one in the trans, and a 4th gen sensor with a sprocket on the driveshaft. Works perfectly. Didn't see any sense in wasting the money on the SGI-5 since I'll be going to a T-56 soon anyway.

 

where did you get the sprocket?

 

Had one laying around the shop. But you can get them just about anywhere. If you're interested in doing it that way, I'll find out for sure where to get one that will work.

 

Ok so reading this, did I infact waste 120 as well on the SGI-5 box????

this would really really suck if I did.

basically Im running a T-5 from my 85, with a VSS from an 89 Trans Am PCM is a 95Z M6 program with !EGR !AC !AIR.

So will the SGI-5 box work for correcting the signal enough to let the car run well, if spliced inline of the VSS to the ECM?

or have I just wasted money?

 

The SGI 5 will not bump the speed up enough to feed the stock LT1 programming, its looking for something much higher than a stock VSS and SGI5 will produce, you may be able to reprogram the computer to a low enough input, but I havent looked into it, the way im doing it just simply feeds the sgi5 a higher pulse signal so it *should* be able to get it to what the pcm expects.

 

Ok if I understand correctly, as long as Im using a none 4th gen tranny, I still need the SGI-5, but I will potentially need something other than the VSS I have.

which is what your working on ..... ok so maybe I can paralelle the test as I plan to put it in the car and hopefully get it on the road in two days .... should be a nice enough challenge.

Can you PM me the other parts to what your testing perhaps I can move forward with it and give you some results.

 

You can program the 4th gen PCM to look for any signal from like 5 pulses per rev up to like 60 or something. Just get the SGI set as high as you can then turn the program down to match.

 

If it will go as low as 5 per rev, that would work taking the output from the buffer box of 4000 / mi and feeding it to the SGI5 then multiplying from there.

 

Ok so PCM tuning isn't an issue, I can have that done.

So obviously my path would be VSS ---> SGI-5 ----> PCM

I can't control the signal from the VSS so it would go into the SGI-5 at whatever level it is, then I can up the SGI-5 to the 4000ppm level, so I would then need to adjust the PCM to 5?


or is there a way to step up the VSS signal and then adjust the PCM.


Do you guys have a formula you use to work this stuff out Im alittle lost on it?

 

I guess I was thinking of doing it a little different.

VSS --> Buffer box --> SGI-5 -->Speedo and PCM

that way you are working with a 4000 ppm signal that is also the correct singal type for the PCM and you are that much closer to what the 4th gen PCM is looking for.

 

Either way he'll be working with 4000 pulses per mile, the vss does that on its own, buffer just changes the type and gives the cruise a 2000 ppm, which the sgi i believe will also output.

 

I don' have cruise so I don't need to worry about that.

Speedo I don't care about cause I plan on buying an autometer one that will work with the PCM.


so really my only needs are getting the VSS signal as best for the PCM.

I also don't have the buffer box you speak of, is it needed or only for Cruise? in which case I don't need.


thx for all this help ..... results will be soon as I plan dropping this engine in in 11 days!

 

.

 

ok.. been away on strike for a few days.. week 6.. woohoo...

anyway.. all that i read is good, to bump down the pulses, I do that in tunercat?
anyone know what the 4000rev/mile translates to in rev/driveshaft assuming 3.73 gears? or for future ref can give the formula.. im pretty sure i got it down.. want to double check.

sorry also 245-50-16 tires. which if right, tunercat says is 812rev/mile