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ARB Choices

Discussion in 'A3/S3 Forum (8L Chassis)' started by jimbobery, Aug 5, 2009.

  1. jimbobery
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    jimbobery S3

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    [Aug 5, 2009]
    I need some new ARBs for my S3, so reading through all the useful info on here 22mm front and 19mm rear is the way to go. That setup can only mean Neuspeed ARBs.

    I was wondering, if this is a good setup, why then are there not more ARBs of this size by different manufacturers. All the ARBs sold by other manufacturers are much bigger, like the ones from DPM:
    http://www.dpmperformance.co.uk/audi-s3-8l-99-03-c-2462_2463_2468.html

    Do manufacturers like H&R actually do and research and development? If they did surely they'd find that their kit of 25mm front and 21mm rear would be creating understeer on the car?

    Or have things moved on and have H&R found a better setup?

    Very confused about what to go for?
    #1
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  3. RmcMills
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    RmcMills Member

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    [Aug 5, 2009]
    Hi,
    I've got the neuspeed 25mm front and 22mm rear on my car and that handles fantastically. very neutral but can induce slight power oversteer on exiting bends.
    #2
  4. IIIadidasboy
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    IIIadidasboy Member

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    [Aug 6, 2009]
    Most A&S3s have 19/15 or 19/14 F-R ARB setups.

    Lots of people have fitted Neuspeed 22mm Front, 19mm Rear ARBs and have spoken very highly of that set-up, which equates to 3mm thicker at the front whilst 4mm/5mm thicker at the rear - and they have been able to reduce the understeer - by proportionally increasing the rear Vs the front.

    Going with 25mm front and 22mm rear, by my calculations means:

    At best you're increasing the front by 6mm (19mm - 25mm) and the rear by 8mm (14mm - 22mm).

    At worst you're increasing the front by 6mm (19mm - 25mm) and the rear by 7mm (15mm - 22mm).

    But either way, you're still proportionally increasing the rear Vs the front = less understeer.
    #3
  5. DPM
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    DPM Site Sponsor Site Sponsor

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    [Aug 6, 2009]
    Got to say we ran the H&R's on our S3 and thought they suited the chassis fantastically.

    Damian @ DPM Performance
    #4
  6. mattyboy199
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    mattyboy199 Active Member

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    [Aug 6, 2009]
    consider R32 ARB's i havent got em but i ve heard / read good things
    #5
  7. S3 Nattie
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    S3 Nattie Quattro ist für sissies

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    [Aug 7, 2009]
    At first I wanted R32 ARB which will keep the standard balance of the S3 but without the roll. Even though H & R will give the S3 a better balance , not to sure if they are worth the extra price. Be good to see peoples suggestion are .
    #6
  8. Olly P
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    Olly P My other cars a mk2 Golf GTi

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  9. DPM
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    DPM Site Sponsor Site Sponsor

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    [Aug 7, 2009]
    #8
  10. WaBBiT
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    WaBBiT New Member

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    [Aug 9, 2009]
    I don't get why 22mm/19mm is the recommended choice? I have 22mm/22mm and if anything, I would want 22mm/23mm or 21mm/22mm, but overall I'm very happy about my setup. :) I thought FWD cars used to have a super stiff rear ARB to prevent understeer/provoke oversteer, now what is the A3/S3 quattro? It is a FWD car with some help in the back, when traction is lost at the front wheels... I believe 22/25 would be a better choice than the 22/19 to go around corners quick, but then, I'm no expert.. I just know that I liked my S3 very much with only the 22mm ARB in the rear and stock ARB in the front (except that the front was to soft of course :p). It had very nice balance and would really push the car around corners, now with the 22mm/22mm it is just a tad less push around the corner, but it feels much more planted than with the stock front ARB.

    Another thing I don't get, why do we compare 1mm increase in the front with 1mm increase in the rear ? This theory would then indicate that a car with 10mm/1mm ARBs would understeer excactly the same as a car with 110mm/101mm ARBs, but isn't there a relationship between increased thickness and stiffness? Like doubling the thickness makes it 4 times stiffer? Increasing 2mm from 2mm (=4mm) would double the thickness and correct me if I'm wrong, but that would make it 4 times stiffer ? So by using this theory a setup of 10/2 to 12/4 would make it less prone to understeer, even though everyone here says it shouldn't change the balance of the car...

    Front: 10^2 = 100 stiffness :)p)
    Rear: 2^2 = 4 stiffness
    Ratio: 100:4 = 25:1

    2mm thicker ARBs:

    Front: 12^2 = 144 stiffness
    Rear: 4^2 = 16 stiffness
    Ratio: 144:16 = 9:1

    So this would mean that 25/9=2,7778:

    So the first setup (10/2) is 2,7778 times more understeered (or something :p) than the second setup...

    And again, I'm no expert, nor do I know what I'm talking about, I'm just trying to figure things out ;)

    (I know that there are other factors to under/oversteer, but now we are only looking at the ARBs :)

    I hope someone can explain the relationship between front and rear ARB, and how 1mm increase in the front and 1mm increase in the rear can be used as a reference to how it increases or decreases understeer, without thinking about the initial setup and the relationship between the two.. (Maybe I'm over complicating things? :p Maybe 1mm is used that way to simplify it?)
    #9
  11. IIIadidasboy
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    IIIadidasboy Member

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    [Aug 9, 2009]
    I'm not an expert either - my ARB knowledge is made up from reading posts on here (and other forums), playing later versions of the PS Gran Turismo series, all sprinkled with a little real-life experience.

    FWD cars are actually set-up to understeer - as car manufacturers do not know the driving ability of everyone purchasing their cars, this is assumed to be the safest option.

    Have you read the "teting" thread written by Glen - it's in the 'stickies' section at the top of this forum - as that was a great write-up which has a nice ARB explanation, where he certainly took into consideration the original set-up of his car and the other suspension mods, as well as comparing them to other cars. An IT contracting guy that once worked on my site had one of the first ever TTs in the country - which I was lucky enough to have 20/30 mins in - so I can totally relate to what Glen says and describes.

    Unfortunately, 99.9999% of people on these forums don't have the budget of an F1 racing team (probably 100% - didn't want to offend anyone! ) - and so unlimited testing of ARB sizes just isn't an option - and so when someone (whos opinion you can trust) finds a good set-up, most people rightly follow it. Having said that, I'm going to try the weitec kit (25/22) together with the Weitec coilovers - just to have a look - but trust me, if I don't like it then I wont trial anything else, it'll be the tried and tested "Ess set-up" going on ;)
    #10

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