ponzia

I have converted my Trans Am from a manual T5 to a Pontiac Firebird 1996 T56. both trans use an electronic speedometer. How can I not get the stock speedometer to work?

tealman92

You need to wire in a new buffer box. Do a search here there are some threads on it.

Tuned Performance

iTrader: (92)

Dakota digital sgi-5e
https://www.summitracing.com/parts/d...SABEgKrvPD_BwE

sofakingdom

iTrader: (1)

Yup. Buffer box.

Gotta get from 17 pulses per rev of the drive shaft coming from the transmission, to 2 going into the speedo. Not too tough really, kinda a no-brainer actually. Those electronic adapter boxes will fix you right up.

Twin_Turbo

iTrader: (25)

You calculate pulses per rev to ppm depending on axle ratio and tire size. Tgen figure out what you need to get a 4k ppm signal. I have used the stock buffer box to get down from a converted 8k ppm. Just use the input and tgen pull vss off the 2k cruise output.

jmd

iTrader: (4)

The 86 Firebird has the 4004 pulse per mile VSS signal at the transmission split and converted (to 2002 ppm cruise, 4004 speedometer, 2002 ECM) by a buffer box. So you only need a single converter circuit device to reduce the trans. signal to your stock buffer box. The SGI-5E works, but a simpler device will too.

scooter

iTrader: (11)

I have an SGI5 box and I am in NJ if you want to buy it from me