[DeTomaso] Fiberglass or carbon race Pantera roof ?

Thu Oct 15 02:22:47 EDT 2009

No matter what the power output, weight remains the n°1 enemy !
Enzo Ferrari used to say " aerodynamics are for those who cannot build good engines". This is another error too.
If you are able to build a light car with great aero, you'll have a car that will be way easier to drive and to brake, to handle in fast and low speed curves, than an other more powerful and heavy car.
Get a Veyron with 1001 Hp, state of the art brakes, tunnel designed aero against a small 200 HP Hayabusa Kawasaki propelled engine prototype , on a curvy circuit, i am not sure the Veyron will come first, because of its weight, despite its huge power output.
Also, the place where the weight is located is critical too: the highest the worst ( hence again, my question about the roof, that is the car's highest part )
And I'm not talking about driving pleasure: driving a light car is so much more fun than a heavy Panzer !
When it comes to affixing the roof carbon panel to the metal sheet, some aeronautical glues ( previously warmed up at the right temperature with a special "gun" - expensive gun, more than 2000 USD) provide better results than just a metal sheet, so this is no more a problem, no rivets, no welding, just high tech glu.
It is amazing to notice how aeronautical technology finds new applications in sophisticated racing : I see the example every day with the ADA car, ( VIN 9628) that is loaded with overexpensive airplane stuff. That's a choice that we've made to make the car the best, fastest and lightest ever
Pat
  ----- Original Message ----- 
  From: michael at michaelshortt.com 
  To: michael frazier 
  Cc: Patrick Hals ; pantera list 
  Sent: Wednesday, October 14, 2009 9:23 PM
  Subject: Re: [DeTomaso] Fiberglass or carbon race Pantera roof ?

  Thanks for responding, I agree that by the time that you add structure and fastening hardward, etc. that the total weight savings won't be worth the expense.
  It would be easier to make the additional 2 hp than to save the 5-10 lb difference, and again, I'm no math wizard, but if a 3100 lb car made 450 hp, that's 6.88 lbs per 1 hp.
  If you save even 20 lbs, that's only 3 hp.  The time, money and sweat equity to save 20lbs would be far more expensive than the few bucks to add the 3 hp.
  The Bugatti Veyron weighs 4,162 lbs.  There are two schools of thought here, The Colin Chapman way of removing washers if he didn't think they were absolutely
  needed to save weight and running a lot less powerful engine or
  building a nice solid, stiff, safe car with lots of horsepower.

  I vote for safety and more ponies.

  Michael Shortt

  On Wed, Oct 14, 2009 at 2:25 PM, michael frazier <red3644 at hotmail.com> wrote:

    Patrick,

     I'm sure you will save a few pounds using CF for the top.  I haven't thought much about what stiffness woud be added

    from a flate plane panel like that, but if done right the CF panels are incredibly rigid. I helped on something like this before

    with a shop that does aircraft panels.  A (relatively) simple conversion would be to make your mold of just the whole top area

    from drip rail to drip rail and from the top of the windshield to the back edge.  Then cut out the center of the roof panel leaving 1/2"-3/4" around the edge.  Recess that material, fit and drop in the CF panel.  Secure it with one of the

    super duper aerospace adhesives and you should be a least as strong as it was before you touched it.  This is a

    method that would leave the original structural members in place.  But then again you can go as far as you like and

    just start duplicating all the panels.  You may end up with a CF Pantera. :)

    Michael Frazier
    Gruppo Rompiculi Corsa

    > From: patrickhals at skynet.be
    > To: michael at michaelshortt.com
    > Date: Wed, 14 Oct 2009 19:05:03 +0200
    > CC: detomaso at realbig.com

    > Subject: Re: [DeTomaso] Fiberglass or carbon race Pantera roof ?
    >
    > Hi Mike
    > No, not a tubular car, just a good ole GR4 with a good roll cage, so flex IS a main concern, hence my question to the Forum.
    > Pat
    > ----- Original Message -----
    > From: michael at michaelshortt.com
    > To: Patrick Hals
    > Cc: detomaso at realbig.com
    > Sent: Wednesday, October 14, 2009 4:24 PM
    > Subject: Re: [DeTomaso] Fiberglass or carbon race Pantera roof ?
    >
    >
    > Can we assume that the car will be fully tubular and that roof strength is not a concern for body flex, etc.
    >
    > Michael Shortt
    >
    >
    > On Wed, Oct 14, 2009 at 8:44 AM, Patrick Hals <patrickhals at skynet.be> wrote:
    >
    > In constant search of saving weight, I am investigating the possibility of
    > having a carbon roof on my future GR4 replica. The rest of the lightweight
    > spares ( front GR4 spoiler with ducts, front hood with vents, rear sugar
    > scoop, 2 doors, rear decklid, GR4 flares and " elephant ears" engine air
    > intakes ) should not exceed 10 kilos in total... That's what I call weight
    > saving !
    > As a matter of fact, and quite unexpectedly, I have recently acquired with a
    > friend of mine, a minority shareholding in a small fiberglass and carbon
    > manufacturing company in Alsace-France ( 20 years of experience) and this
    > will finally allow me to have access to top quality lightweight spares at
    > unbeatable prices, and have other P friends in Europe benefit from it.
    > Does anyone have any experience with that lightweight roof system, like on
    > factory BMW GT4 or Ferrari 430 Challenge that are presently racing in Europe
    > ? How to proceed ? How much weight is eliminated ? What about rigidity ?
    > Many thanks
    > Patrick
    > 2862 Candy - 9628 ADA - 3679 - 4208
    >
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  Michael L. Shortt
  Savannah, Georgia
  www.michaelshortt.com
  michael at michaelshortt.com
  912-232-9390

  This email is protected by the Electronic Communications Privacy
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