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Turning circle radii

Discussion in 'Technical Q&A' started by Smiles, May 6, 2004.

  1. Smiles

    Smiles Moderator
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    Nov 20, 2003
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    Matt F
    I'm posting this in the Tech section in hopes that I'll get some well-informed, technical responses. I hope that's OK.

    Why do Ferraris traditionally have very large turning circles? The 330 GT owner's manually specifically warns against making any attempts to decrease the size of the turning circle, so it must have come up, even back in the 1960s. And modern Ferraris, particularly 12 cylinder cars, carry on this tradition.

    It doesn't seem to have much to do with the quickness of the steering: I've driven some cars with quicker steering and a tighter turning circle. It also doesn't seem to be due to other mechanical reasons, such as an overly-long wheelbase.

    It seems intentional. Is it? If so, why?

    Thanks in advance,

    Matt
     
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  3. Mitch Alsup

    Mitch Alsup F1 Veteran

    Nov 4, 2003
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    Because 1st gear and a judicious amount of power can bring the tail right around.

    Oh, by the way, the large turning radius enables more precision at high speeds.
     
  4. Smiles

    Smiles Moderator
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    I'm not talking about hairpin corners; I'm talking about parallel parking.


    What do you mean by "precision"? Wouldn't it be a function of Ackerman angles, steering gear ratio, and mechanical linkage tolerances? Why would it be a function of turning radius?
     
  5. Smiles

    Smiles Moderator
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    Just to be clear on how big the turning circle is, it's around 44 feet for a 275 GTB, and 45 for a 330 2+2. Compare that to 35 feet for a 360.

    I mean, these are MASSIVE turning circles. Turning around on a two-lane road seems unnecessarily difficult. A normal 3-point turn becomes a 12-point turn.

    Why is this the case?

    Thanks again!

    --Matt
     
  6. Smiles

    Smiles Moderator
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    Here's the factory picture, showing steering stops.

    And here's the factory manual warning: "It is not possible to vary in any way the turning circle as the steering stops are not provided with adjustment screws."

    Couldn't the steering stops be less restrictive?
     
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  8. Mitch Alsup

    Mitch Alsup F1 Veteran

    Nov 4, 2003
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    Sure, grind them off. Just don't complain when the tire suddenly deflates when it touches someting its not supposed to touch.
     
  9. bluekawala

    bluekawala Formula Junior

    Jan 22, 2004
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    Ormond Beach, FL

    The cars you are referring to are GT cars so I doubt the engineers had parallel parking in mind. I'm not trying to be a **** or anything, you do a very reasonable question as far as I'm concerned, but they typically engineer the car for what they think it will be used for at the time. That was probably high speed jaunts from Italy to Paris, or something, not negotiating into the cars spot on the golf green at that latest car show.

    (Basically I don't know :) good question though)
     
  10. enjoythemusic

    enjoythemusic F1 World Champ

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    Good reply. Of course a firm and controlled right foot can make the turning radius smaller :)
     
  11. Steve Magnusson

    Steve Magnusson F1 World Champ
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    I'd add that there might be a sort of "we always did it that way before" factor involved. Cars weren't exactly small back then so what seems like an unusually large turning circle now might not have been so unreasonable back then.

    Look at how opinions/expectations of ride height have changed -- if a 275GTB had the ground clearance of a 360 they would have got a lot of criticism at the time IMO.
     
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  13. enjoythemusic

    enjoythemusic F1 World Champ

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    EXCELLENT point! Am always amazed how small the 308 here looks compaired to the current crop from Maranello. Remember those little Fiats and Alfas from years back? Sitting next to today's SUV makes them look like MatchBox cars!

    PS: and here i am lowering the 308 :)
     

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