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FWD A4 rear brake upgrades

Discussion in 'A4/S4 forum(B5 Chassis)' started by aragorn, Oct 24, 2008.

  1. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator VCDS Map User

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    [Oct 24, 2008]
    Ok i've looked into this before, and the problem i found was that because the FWD's have the disk and hub integrated together you simply cant get larger disks to fit it...

    Now while searching for rear antiroll bars i noticed something interesting:

    The rear axle on a 95-97 A6 (and some audi 100's amongst others) uses the same stub axle as the FWD A4, however instead of a one piece disk/hub assy, they use a small hub which takes the taper bearings just like the A4, then the disk sits over that as it does on a quattro A4.

    Obviously it would require some measuring etc to see if its possible to get everything to line up, clearly the hub will fit the A4 as the stub axle is the same, however i dont know if the usual A4 quattro upgrades will work, as i dont know if the offset of the hub/disk assy would be the same as the quattro setup. (and the A6 disks are the same size as the A4 ones so no upgrade to be had there)

    I might try to get a hold of these hubs and test it out, but if anyone else decides to try it in the mean time, i'd like to hear your results!
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  3. Jason.s
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    Jason.s Active Member

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    [Nov 15, 2011]
    Rather large thread revival but always end up comming across this when searching on google and saves me starting a new thread.

    Now i know i might get the why bother its pointless comments but it`d be good to know anyway.

    Kev, did you ever do anything more with this idea or find out any more info on it before you went quattro?

    Could the Passat B5 rear hubs work? Basically take off all the bearings and stubaxel from the A4 and bolt up the Passat hub along with using the Passat rear discs which are the same size.

    Aside from the hub conversion side of things. I`ve been wondering and whether anyone would know off the top of their head or seen info on it anywhere else, does anyone know if the B6 carriers fit onto the B5 rear? and would the standard B5 lucas calipers bolt up alright?

    Basically wondering if i could use A6 255x10 or maybe squeeze A4 B6 255x12mm discs onto the back with just changing the different hubs, discs and carriers instead of hubs, discs, carriers and calipers which would obviously add another wedge of money if i went with vented rears.

    Is the only thing stopping the S4 rear upgrade on the fwd`s the crappy stub axels instead of hubs?
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  4. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator VCDS Map User

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    [Nov 15, 2011]
    Passat uses C5 A6 rear beam/suspension, so i've really no idea if they'd be compatible.

    I suspect the Audi C4 A6/100 hub would be a good starting point, try it with a standard quattro disk and see where you end up in terms of offset and then decide if you need a deeper/shallower disk, or if you want to space the caliper out.

    Unfortunatley its going to be trial and error, and i came to my senses and stopped wasting money modifying the FWD car before i got a chance to do it myself!

    I know B6 S4 rear calipers have the same hub bolt spacing (ie they'll bolt right onto a FWD or Quattro A4) but on a quattro B5 the offset is wrong and the caliper needs spacing if you want to use it with the B6 disk.
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  5. Jason.s
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    Jason.s Active Member

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    [Nov 16, 2011]
    I see, hhm i could order stuff in, try it and then return it to factory but some of it is Audi only and they`re a bit stricter on returns than what i can do myself here. Time and money to throw at it probably isnt going to be worth the small gain :( No other way to do it other than just throwing parts at it seeing what i can make fit. Being cold outside i really cant be arsed either! lol.
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  6. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator VCDS Map User

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    [Nov 16, 2011]
    The hub will fit as the stub axle is the same part.

    so basically its down to finding a disk and caliper combination thats going to work without tooo much issue in terms of alignment. But until you fit the hub and try on a disk and caliper of known dimensions you'll have no idea where your at!

    Maybe grab some hubs from a breakers, then you only have to order a disk?
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  7. Jason.s
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    Jason.s Active Member

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    [Nov 16, 2011]
    Looking at the ETKA pic, you still have to use a stub axel and then use the hub also?

    ie 17 and 3 and im guessing also you`ll need the ABS ring from it too so 18 aswell?

    [​IMG]

    Would definitely have to find a breakers with one in. Genuine prices are crazy!! Hub is over £100 and the stub axel is over £200!!
    Last edited: Nov 16, 2011
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  8. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator VCDS Map User

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    [Nov 16, 2011]
    3 is the same on both cars as is the abs ring, so you only need the hub.
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  9. Jason.s
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    Jason.s Active Member

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    [Nov 16, 2011]
    Ah right ok that makes things easier..

    Interesting the way they have the ARB like that and also the panhard rod. Shame we cant adapt those to fit on the back of the fwd A4`s..
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  10. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator VCDS Map User

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    [Nov 16, 2011]
    It looks pretty weird.

    The A4 uses a twist-beam rear axle, where the actual beam itself acts as an antiroll bar, whereas that A6/100 rear axle looks more like a solid beam axle with trailing arms, hence the panhard rod and external ARB. The A4 setup is most likely the better of the two.
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  11. Jason.s
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    Jason.s Active Member

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    [Nov 16, 2011]
    Aye just be nice to some how use those as a brace on the existing beam, eliminate some of that twist which is what the Obar and Shine bar in America does.
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  12. tonya4
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    tonya4 TDi Powerrrr

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    [Nov 16, 2011]
    I know of a K reg Audi 100 2.5 that maybe being broken due to a front end shunt.Is this car likely to be the right one to get the parts from?I could mock it up on my breaker avant and see how it lines up

    tony
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  13. Jason.s
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    Jason.s Active Member

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    [Nov 17, 2011]
    Looking on ETKA its the same setup yeah so could be trialed if you were willing to!
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  14. ScottD3
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    ScottD3 I want your faulty electronics

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    [Mar 25, 2012]
    Bit of a bump and just out of simple old curiosity.
    What ever happened to this idea?
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  15. Jason.s
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    Jason.s Active Member

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    [Mar 27, 2012]
    I didnt do anything with it from lack of cash to throw around on a hunch and couldnt be arsed to try and find the right parts to do it. If i knew it`d work perfectly and knew all the right parts to find to swap the bearings and do a brake upgrade at the same time i`d slowly order/search parts for it. Need someone with the time and more money than me to try it then can follow suit :p
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  16. ScottD3
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    ScottD3 I want your faulty electronics

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    [Mar 27, 2012]
    I got the time but not the money.

    I need a Sugar mummy I think.
    #15
  17. Jason.s
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    Jason.s Active Member

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    [Mar 27, 2012]
    Dont we all!
    #16
  18. Bradderz_1988
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    Bradderz_1988 Dont replace it, Upgrade it !!

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    [Jul 23, 2012]
    Ive just found a possible solution its from a passat so not sure but it might be worth a look into but may be costly. It uses 312mm front disc, S4 rear calipers and custom brackets and S4 rear caliper hoses.

    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]

    dont no if he had problems with it or what but it looks to me as though he needs some bigger pads and the disc grooves the right way lol
    Last edited: Jul 23, 2012
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  19. Jason.s
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    Jason.s Active Member

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    [Jul 24, 2012]
    Looks good, just doesnt solve the issue of whether changing to the 100/a6 stubaxel and using a normal disc works.
    #18
  20. Bradderz_1988
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    Bradderz_1988 Dont replace it, Upgrade it !!

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    [Jul 24, 2012]
    I kinda realised that after i posted it remembering that the passat has the a6 rear setup :( my bad .. sorry lol
    #19
  21. ScottD3
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    ScottD3 I want your faulty electronics

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    [Jul 24, 2012]
    We need to get some free/damage but useable 100/A6 stub axles?
    #20

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