shanebang76

I used to hear peaple talk about speedo calibration kits and I just ordered a granetelli kit from jegs. Should this work?? I have had this tranny in car for 5 years and no speedometer. Integrator wiring harness from Street and Performance was supposed to make it work but it never did. Any replies will be appreciated!!

Black6SpdTA

The only way I've ever seen is the Dakota Digital SGI-5 for 80 bucks. Go to www.dakotadigital.com and check it out.
-Rippin

87camracer

i was always under the impression if everything was hooked up and working correctly that the 90+ speedos should work just fine with the t56. starting in 90 gm went to an electrical speedo but it might be the VSS in the tranny is not sending out the correct signal...please someone answer this cuz im tossin around throwin a t56 in my 91 trans am...

Slow91z

yes they are electronic speedos, but the pulse rate is different...you need a converter like the dakota rippin was talking about...I don't know anything about the granetti it may work also.

slimdawson

I see you have an LT1 intake. What kind of pcm/ecm are you using?

I have a t56 in my 91 RS but I also have the LT1 so it makes the situation a wiring deal.

I am curious if the 91 vss will fit in the t56. If so, it seems people could get around using the dakota box.

Answer the first question and I may be able to help you.

Later, Mike

shanebang76

Nope, the 91 T5 VSS sensor was not the same one as the T56. Tried it back when I first installed six speed back in 98', it was a different plug, so I got the trans wires off of 96 TA donar car's wiring harness.... still didnt work with my speedo.....it would make bury all the way out and then go back and sit on 0, after about 1000 feet. So I have drove it since 98 with no speedo....I just go by the tach!

shanebang76

Im using a Street and Performance TBI to TPI adapter harness along with stock tock 91 harness. I run a 91 TPI computor and an "integrator" computor which the TBI harness plugs into, it then has a harness that comes out and runs the TPI intake. I have a 95 LT1 intake on it modified by John Millican at lt1intake.com!

slimdawson

So you don't have the tbi computer any more?

I see you tried the 91 vss in the t56. Did the unit itself not fit into the tranny? I had the same problem with the speedo going nuts but all it was, was a wiring problem on my part.

If the sensor itself won't fit, we need to find out what ppm the t56 generates. Do you know?

Later, Mike.

TheGreatJ

The T-5/700-R4 VSS is about 2.5" in diameter IIRC. The T-56 VSS is like 3/4". The T-56 also uses a MUCH higher pulse rate...somewhere in the thousands per mile. Mine makes 17 pulses per driveshaft rotation (counted the teeth on the pulse generator when I had the trans apart.) Assuming 3.42 gears and a 26" tire that's about 2850ppm. I believe the older VSS's make around 900ppm.

The pulse rate will vary with tire size and rear end gearing. Smaller tires and higher (numerical) ratio gears will raise the pulse rate.

shanebang76

Yeah, the sensor was totally different than 91 model!!! Street and performance sent what they called a speedo"splitter" that would make this work. dont know if I hooked it up right though.... dont know if I was supposed to splice wires into VSS wires from tranny, or splice into speedo wires from instrument cluster in dash?????? anyone know????

Slow91z

Why don't you ask them and tell us.

shanebang76

Ive sent them several e-mails, but they dont ever reply!!! they told me to reprogram my chip, it would be 150$. I think not!!! Had john millican to reprogram S&P chip and he said that it was basically stock... no changes to the fuel tables and they didnt even have a place to program in gear ratio in chip...... And they charged me like 300$....I highly encourage everyone to stay away from those guys!!! I would go back with howell or painless wiring next time!!! S&P's tech support really sucked for me!! Just my 2 cents on Street and Performance!!

Slow91z

Hmm sounds like i'm never gonna deal w/those people.