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Manual /Automatic Transmissions in Avantis

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  • Manual /Automatic Transmissions in Avantis

    A 1967 Avanti II has recently been listed on ebay with this description for the transmission:"Borg Warner 4-speed man/Power Shift 3sp automatic". The car has an automatic transmission but the driver can, it seems, run it through the speeds manually by shifting using the floor shifter. Is that a good idea?
    In a simular vain, which transmission would give the better results in an Avanti in a drag race, a four speed manual or an automatic? Assuming the same rear end, which transmission would give a higher top speed? Generally, automatic transmission autos have a higher or a lower rear end? (At one time I knew the answer to this last question.)

  • #2
    To: herbpcpa,---- That's a nice looking Avanti! I think the owner is saying that either transmission was available in 1967. This car is a 3 speed auto.


    • #3
      Am not an expert, and don't wish to insult your intelligence by making the answer too elementary -- but that's my level of expertise.
      1. Older automatics lost some torque through torque converter slop, so (theoretically) a car with standard shift should be able to achieve a higher top speed, all other factors being equal.
      2. Standard transmissions transmit all available hp to the rear wheels, so a driver who can shift very fast (Ted Harbit) would normally be able to beat a similar car with an automatic in a drag race.
      3. Modern automatics lock up their torque converters in their highest gear, so item #1 would not necessarily apply in a new car.
      4. All other things being equal, cars with automatics were often equipped with higher (lower numerical) rear axle ratios, both to overcome item #1 and because the TC slop allowed their engines to get up higher on their torque/hp curves to get the car moving from a dead stop. Vehicles with stick got a lower RA ratio to help them get moving without too much clutch slippage.
      Last edited by Skip Lackie; 05-21-2012, 01:23 PM.
      Skip Lackie


      • #4
        The listing for that 1967 got me confused at first, then I realized that he just pulled some information from somewhere and listed what was possible for the Avanti.
        That Avanti is a 327, AT, A/C car.
        The S/N is correct for a 1967 model.
        Gary L.
        Wappinger, NY

        SDC member since 1968
        Studebaker enthusiast much longer