Topic: Torque Converter
in Forum: C3 Driveline Components
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West Bend, WI - USA
Joined: 3/18/2010
Posts: 46
Vette(s): 1985 silver coupe & 1975 red coupe
Another question for you guys. I have a 1981 Vette I bought a short time ago and it's been modified. The former owner put on a different intake manifold and a Holley carb. He also installed a vacuum advance distibutor on the thing. The problem now is the torque converter won't lock up. I understand I can install a manual switch so it will.Can somebody explain how to do that and how much of a difference in RPM will it make. Thanks much for any help you can give me, Darrell
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Duncanville, TX - USA
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Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
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#2-1985 Bright Red/Carmine Cp.L-98/auto
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Lock-up on a 350 will give you about a 200 rpm drop....not really much good except on a long road trip, fuel mileage-wise.
In order for the LU to work, it needs 12v & ground at the solenoid, an rpm signal, and vehicle speed signal. With the different distributor, you probably no longer have a valid engine rpm input.
You can wire the trans with a 12v source, and use the pressure switch that is already there to provide the ground, but it will go into LU as soon as it hits 3rd gear. In order to control WHEN lu comes in, you can install a switch on the 12v power wire. Flip it on when you want LU to engage, and off when you don't. With the pressure switch, it will only engage in 3rd gear anyway.
Some folks use a vacuum switch to control the power to the solenoid, so that is also an option.
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in Forum: C3 Driveline Components
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