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Discussion in 'Vintage (thru 365 GTC4)' started by Bob Zambelli, Sep 11, 2007.

  1. DWR46

    DWR46 Formula 3
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    Jun 19, 2012
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    Steve: 3757 build sheets list the helper springs. I do not have the sheets for 3869. One more time, ALL the 250 GTO's and 330 LM's WERE BUILT with the helper springs. What individual owners did after the cars left the factory was up to the owners.
     
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  2. miurasv

    miurasv F1 Veteran

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    #477 miurasv, Jan 18, 2020
    Last edited: Jan 18, 2020
    Great, Dyke. Thank you very much for clearing that up. Do you have a view on the helper springs' effect on the handling, or rather by not using them?
     
  3. DWR46

    DWR46 Formula 3
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    Steve: We use the helper springs as the factory intended. Over all the years, I have become more and more impressed by how smart the factory engineers actually were in using the technology and knowledge of the day. There is a very good reason Ferrari won so many races in the era. They really knew what they were doing. The next thing to remember is that "racers" are NEVER happy with the car, and they ALL think they can make the cars better. This is still today how so many good race cars end, after a few seasons, all screwed up.
     
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  4. miurasv

    miurasv F1 Veteran

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    Steven Robertson
    Makes sense. Thanks.
     
  5. John Vardanian

    John Vardanian F1 Rookie

    Jul 1, 2004
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    #480 John Vardanian, Jan 19, 2020
    Last edited: Jan 19, 2020
    The 250GT/L also has the concentric coils over the Koni dampers. They are made from pretty thin diameter wire.

    john
     
  6. miurasv

    miurasv F1 Veteran

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    #481 miurasv, Jan 19, 2020
    Last edited: Jan 19, 2020
    Lusso has springs on the rear Koni shocks only, not the front shocks.
     
  7. miurasv

    miurasv F1 Veteran

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    #482 miurasv, Jan 19, 2020
    Last edited: Jan 19, 2020
    250 GTO came in 3 different body styles; original '62, '64, both styles with detail differences as they evolved, and the sole LMB. I haven't read anywhere that the original style's front and rear window measurements ever changed, although the windows may have been made to fit the individual bodies after they were built. Some of the early cars with cabin air vents in the sail panels did not have the cabin exhaust vent in the rear window.
     
  8. DWR46

    DWR46 Formula 3
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    Series I GTO's all had the same windshield from the factory. Now, after 60 years of accidents, every car takes some "tweaking" to correctly fit a new windshield. GTO/64's are much different.
     
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  9. miurasv

    miurasv F1 Veteran

    Nov 19, 2008
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    1964 250 GTO 5571GT Chassis Plate.

    Is the 250 GT/L on the chassis plate correct? I can't see the owner having an incorrect plate on this car. It states in Pourret's 250 book that 1963 GTOs have chassis plates inscribed GTL. Does anyone know if 5573 and 5575 also have GT/L inscribed on the chassis plate?

    Pic Bjoern Schmidt.

    Image Unavailable, Please Login
     
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  10. DWR46

    DWR46 Formula 3
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    5575 Chassis Plate: Autotelaio reads 250 GT/L. However the Tipo reads 250 GT/LM. That should keep all the "historians" up late tonight trying to determine what the factory was doing.
     
  11. bruno roumilhac

    Jan 24, 2020
    3
    Full Name:
    bruno roumilhac
    here is an anecdocte on the suspensions of the 250 gto and the reason why the spring is so weak; testimony of a friend who collaborated 10 years in maranello and who knew mauro forghieri from 1978 to his departure in 1987

    "" A rough prototype had been assembled on the modified base of a 250 SWB coupe. This prototype, in the hands of John Surtees, had driven 4 seconds faster than the 250 SWB on the Monza circuit. Which, when it comes to season-to-season performance, is just huge.
    The highway from Bologna to Florence had just opened recently, when Mauro Forghieri entrusted the Proto 250 GTO to Willy Mairese.
    At the exit of a gallery, a gust of wind deflected the proto from its trajectory and it collided with the protections on the right side of the road. Mauro asked Mairese what had happened. The Belgian pilot stated that he had not mastered the large oversteer caused by the rear axle and that he was in no way involved *. Mauro had always considered Willy to be an honest man, so he started to find out where the oversteer in question came from. The means of investigation are very rudimentary and only a bar of 5 meters long, in support, made it possible to highlight a defect of guidance of the rear axle, which was suspended by leaf springs and springs helical around the shock absorbers. In fact, under heavy stresses, the rear axle was no longer perpendicular to the center line of the car and became directional.
    The problem of the modification is insoluble because the homologation sheets for the 1962 campaign are all approved by the FIA and nothing can be changed. The first GTOs are in production and known customers. The season starts in a few weeks.
    Mauro spent a few sleepless nights before finding the problem and especially the solution. In fact, the springs around the shock absorbers are in contradiction with the leaf springs. After long reflections and in-depth studies of the homologation sheets, it appears that the coil springs appear on the sheet, with the empty height, the number of turns, the outside diameter, but not the diameter of the torus. impossible to make them disappear. The solution consisted in mounting springs whose diameter of the torus was therefore less than 4 mm, completely ineffective. The rest is well known: the 250 GTO has won everything! 880 kg for 300 hp with a 12-cylinder engine identical to the 1958 Testa Rossa which is also almost indestructible because limited to 7000 rpm.
    Thus at 26, this genius, full of doubts about his abilities, solved a very important behavioral problem never brought to light before the trip of Willy Mairese.
    Today, GTOs are mainly equipped with adjustable shock absorbers and variable pitch springs, on the original leaf springs but, nobody refers to the record of the time because they are most often found in collections private or in museums or on a circuit demonstration. ""
     
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  12. miurasv

    miurasv F1 Veteran

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    #487 miurasv, Jan 24, 2020
    Last edited: Jan 24, 2020
    Ing. Forghieri actually explains the situation in a Davide Cironi interview from about 11' 50" in the video below. The first few GTOs had been produced, where Mairesse tested one of them and had an accident coming out of a tunnel on the Bologna Firenze autopass due to the car oversteering/self steering. Interestingly, due to this accident, and to prevent the car from oversteering, Forghieri added the Watts Linkage, but it did not solve the problem, which was down to the helicoidal springs which were working against the Leaf Springs, but because the GTO was already homologated with the helicoidal springs, they had to be kept, and could not be removed. To solve this, Forghieri had to make the springs ineffective, so reduced the diameter of the springs to 1mm, which he could do because the diameter of the springs had not been specified in the homologation papers. We now also know why these cars have the Watts Linkage.

    I wonder which 250 GTO it was that Mairesse crashed?

     
  13. turbo-joe

    turbo-joe F1 Veteran
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    Apr 6, 2008
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    just found this:



    real GTO? don´t think so
     
  14. miurasv

    miurasv F1 Veteran

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    Replica, based on based on Ferrari 330 GT 2+2 #6477GT.
     
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  15. miurasv

    miurasv F1 Veteran

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    I asked Ing. Forghieri if it was the prototype GTO or a production GTO that Willy Mairesse crashed while testing coming out of the tunnel on the Bologna Firenze autopass, and he very kindly replied that he believes it was a production GTO. However, it is too far back for him to remember the chassis number of the car, and that of the prototype.
     
  16. anton

    anton Karting

    May 8, 2004
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