98 Firebird LS1 carb swap
05-10-2010 | 11:54 PM
#1
Thread Starter
Teching In
Joined: Apr 2010
Posts: 2
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From: Southaven, MS
98 Firebird LS1 carb swap Hey everyone. Quick question. I have a 98 firebird LS1 with the following mods:
Edelbrock performer LS1 intake
Quick fuel 750 carb
Hooker LTs(no cats)
Built 700r4 Trans (BTE 2800 stall)
Thumper cam (235/249)
My question is, when the trans was swapped, of course the speedometer stopped working. I do drive this car on the street a good bit so I was wondering what can I do in order to get the stock speedo to work again. Any ideas/links? Thanks
Edelbrock performer LS1 intake
Quick fuel 750 carb
Hooker LTs(no cats)
Built 700r4 Trans (BTE 2800 stall)
Thumper cam (235/249)
My question is, when the trans was swapped, of course the speedometer stopped working. I do drive this car on the street a good bit so I was wondering what can I do in order to get the stock speedo to work again. Any ideas/links? Thanks
05-11-2010 | 04:15 PM
#3
Your ABS system uses VSS' on each of the wheels. Hook the VSS wires up to a early 90's truck buffer box and it should output the necessary signal to drive your speedo
The box needs to be from an early 90's truck because those were the only ones that got the TBI engine along with the (early) 4L60E which used the newer style 40ppr VSS
Plan B would be to grab an electric VSS, drive/driven gears from a 80's RWD car/truck along with the speed buffer box and install those in your trans. Your 700R4 might actually have this already, go check
The box needs to be from an early 90's truck because those were the only ones that got the TBI engine along with the (early) 4L60E which used the newer style 40ppr VSS
Plan B would be to grab an electric VSS, drive/driven gears from a 80's RWD car/truck along with the speed buffer box and install those in your trans. Your 700R4 might actually have this already, go check
05-13-2010 | 04:20 PM
#5
The 700-R4's use a gear in the tailshaft and the 4L60 uses a speed sensor to send speed to the speedo, not the wheel speed sensors.
I think they make a box that the gear driven cable hooks into and switches that to an electronic signal that the original plug would go into for the speedo to work.
I think they make a box that the gear driven cable hooks into and switches that to an electronic signal that the original plug would go into for the speedo to work.
05-13-2010 | 06:43 PM
#6
Correction, they use two gears. The drive gear is on the output shaft attached via clip. The driven gear moves the VSS which sends the speed signal to the ECM/PCM. These gears must be matched to the rear gear and tire size. If the 700R4 is a cable driven unit, then none of this matters because an electric VSS will not fit in the cable VSS hole
The ABS reluctor suggestion was to use what he already has without ordering new conversion parts
Also, the 4L60 does not use a reluctor to send the speed signal, its still gear driven. The 40 tooth reluctors werent used until the 4L60E's came out
Several conversion boxes and external VSS' exist, but are solutions to non-existent problems in this instance
The ABS reluctor suggestion was to use what he already has without ordering new conversion parts
Also, the 4L60 does not use a reluctor to send the speed signal, its still gear driven. The 40 tooth reluctors werent used until the 4L60E's came out
Several conversion boxes and external VSS' exist, but are solutions to non-existent problems in this instance
