I am in the middle of and LT1 swap and I'm doing all wiring myself . What I need to know is exactly how the speedos in the 90-92 camaros work . What I need to do is give the new LT1 computer a speed signal . What makes this a little trickier is Im using my original 700r4 with a 6-speed 95 Mass-air LT1 computer . Basically I don't know how I'm gonna make the speedo work properly . Anybody have any advise they can offer .

Thanx

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Derek 90 IROC 5.7
Mods: All the usual bolt ons siamesed base , 2500 stall , 373's , SS hood ,big and littles , lotta reduced weight. Stock heads/rockers , cam ,runners , chip and TB
Best Et: 13.12@101 ...1.701 60 ft.

 

The '90 - '92 systems use a magnetic VSS in the transmission, and a VSS buffer in the ECM. The VSS connects to the ECM, and the ECM outputs a 4000 pulse per mile signal to the speedometer and a 2000 pulse per mile signal to the cruise control. I'm not sure what the LT1 ECM expects as a VSS input, but I'd bet that it's the same as the '90 - '92 system.

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Tim

1992 Z28, 305 TPI 5 speed, 12.1 sec @ 114.7 mph

1984 Berlinetta 305 TPI Auto, 13.8 sec @ 99.7 mph

 

Thanks Tim

I did find out that the both the 4l60-E and T56 VSS's are different from 94-up . I am using a 95 Mass-Air 6-speed computer and harness but retaining my 90 model 4L60 ( 700-r4 ) . I will have full control over every aspect of the computer thru LT1 edit software . I just need to find out how Im gonna give the LT1 ECM the correct speed signal . For reference the 4L60-E computer uses a 40 pulse per D.S revolution and the T56 uses a 17 tooth per D.S rev. sensor .