Cars We Drive!

Discussion in 'Fine Living, Home, Design & Auto' started by Bert1568, Jul 18, 2006.

  1. Arthur PE

    Arthur PE Senior member

    Messages:
    728
    Likes Received:
    18
    Joined:
    Jan 22, 2012
    Location:
    Earth
    not mine, just an internet pic
    I don't own one (but this has got me considering one again)
    my boss owned one in the early 90's and he let me drive it on occassion, and it was a heck of a car
    a more current similar car (for a good budget price) is the C43 AMG, basically hot rodded V8 in a C classe

    there are so many good cars, in all budget segments, new or used, current or 'classic' to choose from...that is GOOD thing

    M3: imho the best M3 was one we didn't get, the mid 90's e36 euro version, 321 HP, 7800 redline, 6 TB I6
    car could touch 190 mph and handled like it was on rails, and would run with any non-turbo 911 variant

    [​IMG]
     
    Last edited: Mar 4, 2012
  2. impolyt_one

    impolyt_one Senior member

    Messages:
    14,457
    Likes Received:
    4,790
    Joined:
    Sep 6, 2006
    Location:
    The Temple of Jawnz
    Those M5's didn't have composite brakes, I don't think BMW even made composite brakes til this year on the M6 that hasn't even been released yet (?) - you're like two decades off with that. In the early '90's those Euro M cars had two-piece floating rotors with machined hats, big pot calipers - same parts as the 850CSi, so nothing outstanding by today's standards.
     
    Last edited: Mar 4, 2012
  3. Find Finn

    Find Finn Senior member

    Messages:
    12,358
    Likes Received:
    3,484
    Joined:
    Sep 10, 2010
    I'm pretty sure the current M5 has them.
     
  4. Arthur PE

    Arthur PE Senior member

    Messages:
    728
    Likes Received:
    18
    Joined:
    Jan 22, 2012
    Location:
    Earth
    yes they did, and yes they do
    composite (as in more than 1 part), not ceramic/carbon fiber
    at least that is what BMW called them



     
  5. Arthur PE

    Arthur PE Senior member

    Messages:
    728
    Likes Received:
    18
    Joined:
    Jan 22, 2012
    Location:
    Earth
    the one I saw did not, but it may be an option


     
  6. A Y

    A Y Senior member

    Messages:
    5,594
    Likes Received:
    379
    Joined:
    Mar 12, 2006
    Location:
    Southern California
    The F10 M5 has standard composite or two-piece rotors (iron disk, aluminum hat). The new M6 is said to have ceramic brakes, which are also composite (by necessity).

    A popular upgrade for US-spec M3s was replacing their one-piece rotors with Euro-spec two-piece rotors. It was believed that liability concerns (due to the Al hats cracking in standard wear and no one checking for that) that they weren't in US cars but unless you are a very fast track driver, there really was no good functional reason for this upgrade.
     
  7. Arthur PE

    Arthur PE Senior member

    Messages:
    728
    Likes Received:
    18
    Joined:
    Jan 22, 2012
    Location:
    Earth
    I put the 2 piece euro on my e36 (front only)

    iirc the e46 came with floaters on the front, but not x-drilled (I think the rears were floaters too)
    I put the euro x-drilled front and rear

    I heard the reason was liability, the rotors will crack at 100k miles and Americans do poor maintenance
    one big advantage is the radial run-out allowed by the opins, they wobble/vibrate less



     
    Last edited: Mar 4, 2012
  8. A Y

    A Y Senior member

    Messages:
    5,594
    Likes Received:
    379
    Joined:
    Mar 12, 2006
    Location:
    Southern California
    The E46 M3 competition package came with the two-piece rotors. The floating pins are necessary because the Al hat and Fe rotor had different thermal expansion characteristics. If rotors and pads are properly bedded, they won't have vibrations.
     
  9. Arthur PE

    Arthur PE Senior member

    Messages:
    728
    Likes Received:
    18
    Joined:
    Jan 22, 2012
    Location:
    Earth
    the std car came with floaters too, but not cross-drilled

    they only used dissimilar metals because they were floating (not for weight, the hub is on axis, very little rotational mass/inertia)
    that way the hub could be cast around the pins
    anything mated perfectly will fit perfect, but it is an imperfect world
    so the radial play will allow the rotor to expand unconstrained and reduce distortion: wobble and vibration
    the pins are fixed to the hub and slide on the rotor
    on a rotor that doesn't get real hot often, not a big deal
    a floating caliper remedies a lot of that, but it is aggrevated with the fixed type



     
    Last edited: Mar 4, 2012
  10. Arthur PE

    Arthur PE Senior member

    Messages:
    728
    Likes Received:
    18
    Joined:
    Jan 22, 2012
    Location:
    Earth
    the pins also allow the rotor to move axially or laterally
    so it can expand without 'coning' which reduces pad contact area and the edges digging in
    and can absorb a bit of lateral run-out
    on x-drilled important becasue they shouldn't be turned, where as a regular disc can be turned a bit when uneven due to wear

    they can also isolate the hub thermally, keeping the bearings cooler
     
  11. mainy

    mainy Senior member

    Messages:
    1,990
    Likes Received:
    775
    Joined:
    Sep 12, 2006
    [​IMG]

    they are multiplying.... still need to get new wheels for 951
     
  12. A Y

    A Y Senior member

    Messages:
    5,594
    Likes Received:
    379
    Joined:
    Mar 12, 2006
    Location:
    Southern California
    The EU spec ones came with floaters, but the US versions had single-piece rotors if they didn't have ZCP.

    The important weight difference is that it is unsprung weight. Rotational weight is not the issue. In order to get a rotor of a certain size and reduce weight as much as possible, you had to use a composite construction. Most big-brake kits actually increase unsprung weight, but in exchange they give you bigger rotors.

    I'm not sure we are saying different things. Different materials mean different parts of the brake disc expand differently. This leads to distortion hence the use of floating pins. Coning for 1-piece rotors has to do with cooling problems and the rotor design itself.

    BMW rotors in general shouldn't be turned as they are already pretty thin brand new.

     
  13. RFX45

    RFX45 Senior member

    Messages:
    16,352
    Likes Received:
    6,101
    Joined:
    Aug 22, 2006
    

    It's amazing the kind of computer and gizmos they managed to put into this car but the 458 Italia is just the best of the best Super cars right now and that cost more than $100k less. Not to mention that stupid dealers buys the LFAs so they can sell it with a mark-up since i don't think they can't charge more than MSRP iirc.

    It's a good starting point to show that they're back and serious about making sports cars again though, now they just need to release a sports coupe to compete with the M3, C63 and the upcoming RS5.
     
  14. A Y

    A Y Senior member

    Messages:
    5,594
    Likes Received:
    379
    Joined:
    Mar 12, 2006
    Location:
    Southern California
    Speaking of supercars, I'll take one of these please.

    Ferrari F12 Berlinetta

    6262 cc, 65 degree V12 direct injection.

    740 CV (730 HP) @8250 rpm.
    690 Nm (509 ft/lb)@ 6000 rpm (80% available from 2500 rpm).
    Power to weight ratio 2.1 kg/cv.
    30% more fuel efficiency over the 599 GTB

    Dry weight (with optional LTW components) 1525 kg/3362 lbs
    Aluminum alloy space frame chassis.
    weight distribution 46% front 54% rear.

    76% more downforce @ 200 km/h than the 599 but with less drag

    Body is 20% more rigid than the outgoing 599 GTB.

    [VIDEO][/VIDEO]
    [VIDEO][/VIDEO]
    [VIDEO][/VIDEO]
    [VIDEO][/VIDEO]
     
  15. RFX45

    RFX45 Senior member

    Messages:
    16,352
    Likes Received:
    6,101
    Joined:
    Aug 22, 2006
    Saw that last week, car is going to be insane! Suppose to be smaller and lighter than the 599 but with that much power and torque while only weighing 3362 lbs. It doesn't look horrible but I do wish it didn't remind me too much of the FF.
     

Share This Page

Styleforum is proudly sponsored by