Recent content by croc

  1. C

    Weismann FTA ?

    Thanks. Welcome aboard Pat Weismann. ;) Ian
  2. C

    Weismann FTA ?

    I like the 930 and Weismann low ratio CWP set-up (i.e. 4.22 etc) so that gear wheel sizes can be "evenly spread" rather than granny geared. With this set up, the shifting can be put on the intermediate shaft, which is what Weismann did. Clever! Strangely, not all Porsche gearboxes are like...
  3. C

    Weismann FTA ?

    Hi Roark, Got it. Thanks for the clarification :thumbsup: . By the way, you say that 700 ft.lbs output will move a 3500 lbs car from a dead stop - how do you calculate this? Tom, Well said. I know it’s a bit far-fetched but is there a formula to calculate the lowest output (in top...
  4. C

    Weismann FTA ?

    You mean plotting a graph of mph against rpm using this formula? mph = rpm x 60 x 2π x RR x (Tp/Tw) x (Tdriving/Tdriven) 36 x 1760 RR= tyre rolling radius (in) Tp= no. of teeth - pinion Tw= no.of teeth - crown wheel Tdriving= no. of teeth - driving gear ratio Tdriven= no. of teeth - driven...
  5. C

    Weismann FTA ?

    Re: Weismann WFA ? OK, will do.
  6. C

    Weismann FTA ?

    Re: Weismann WFA ? Yes but normally the final drive (CWP) ratio is calculated with a fixed top gear (1:1 or slight overdrive for economical cruising) at desired top speed. Then the remaining gear ratios are figured out to keep the powertrain in its powerband. Why would a racing car need an...
  7. C

    Weismann FTA ?

    Weismann Transmissions Does anyone have any pictures showing the insides of the old FTA? I’d like to see the gears. Carroll Smith mentioned in one of his books that the basic differences between the two brands [Hewland and Weismann] are that Weismann does all of his shifting on the intermediate...
  8. C

    How to design a gearbox book recommendations?

    Thanks guys for the clarification. The 6th gear ratio in the GT3 is 0.86, so the formula is very accurate indeed. The book even explains the differences between Gleason, Klingelnberg and Oerlikon. :thumbsup:
  9. C

    How to design a gearbox book recommendations?

    I finally got the book last week. It is a good book, I've not read everything yet but however there is one thing that I'm not sure I understand : If I take a 2004 GT3 as an example, the calculation is as follows: (I assume the tyre radius is in inches) 190 (mph) x 36 x 1760 7400 (rpm) x 60...
  10. C

    Are our kiwi buddies OK?

    Hope you are all OK. Keep us updated. Best wishes from the UK.
  11. C

    Use a drop gear to lower/raise gearbox?

    There is a F40 gearbox for sale (No affiliation): Ferrari Ferrari 40 Spec Sheet Interesting, but no, I'm not going to buy it.
  12. C

    Design differences between street and race gearboxes

    ^ Thanks.
  13. C

    Use a drop gear to lower/raise gearbox?

    I'm surprised that 308/328 were transverse engined. Here is a pic of the Testarrosa trans (where is the drop gear, clutch & bellhousing? :huh: ): Regarding F40, it seems to me that the distance between the bellhousing and centre of driveaxles is about 300mm (100mm more than Boxster) so...
  14. C

    Use a drop gear to lower/raise gearbox?

    Jac, I'm not going to do a commercial vehicle hypoid afterall so please ignore my last post above. Been reading more stuff (particularly page 20): http://www.draftingzone.com/shoppingzone/4-9-1.pdf
  15. C

    Use a drop gear to lower/raise gearbox?

    Well, the actual picture of what I want is a upright Getrag G96.96 trans (GT3) with a flipped CWP. It's similar to the G50.50 but with slightly different casing. Yes, it has 10mm hypoid but I will try to get a "commercial vehicle hypoid" CWP set made by a reputable company. I wish to explain how...
See more
Back
Top