S8 Anti-roll bar
 

Random thought.

The S8 runs a larger Anti-roll bar that my TDI and possibly other A8s.

Has anyone fitted a S8 Anti-roll bar to their A8?

Its on my to-do-list, but not done yet.

I think Sport and S have the same antiroll bars, non Sport have smaller, at least that's how it usually is on Audis. And RS models usually only have rear antiroll bar stiffer than S/Sport models but the same on front.

It changes through the model years and engines, but as for the 2006 model:

PR-codes:

PR-1BK+T15, T41,T81, T82, T14, T8T, T44 Anti-roll bar size 30,3X3,4 mm. Part number 4E0411305AA.

PR-1BK+T42, T1H, TB1 Anti-roll bar size 30,8X3,5 mm. Par number 4E0411305AB.

PR-2MA+T15, T41, T81, T82, T14, T8T, T44 Anti-roll bar size 30,8X3,5 mm. Part number 4E0411305AB.

PR-2MA+T42, T1H, TB1 Anti-roll bar size 31X4,7 mm. Part number 4E0411305AC

PR-2MB+T8E Anti-roll bar size 31X4,7 mm. Part number 4E0411305AC.


Out of this, we see that the 4.0TDI, 4.2TDI and W12 with sport suspension has the same size anti-roll bar as the S8.

1BK -> normal/standard suspension.
2MA -> sport suspension.
2MB -> sport suspension S8.

This was only for the front, and for the rear:

Here I don't have the size, but I can compare the part numbers.
PR- and engine-codes:

PR-1BK+BFM, BFL, BAR, BPK, BVJ, BHT, BSB, BSM, ASN, BNG, ASB has part number 4E0511407D

PR-1BK+ ASE, BHT, BTE, BVN, BMC has part number 4E0511407J

PR-2MA+ BFM, BFL, BBJ, ASN, BAR, BPK, BFM, BGK, ASB has part number 4E0511407J

PR-2MA+ ASE, BHT, BTE has part number 3D0511407B

PR-2MB+T8E has part number 3D0511407B

Here we see that the 4.0TDI and the W12, both with sport suspension, has the same rear anti-roll bar as the S8.



Not so complicated after all? +++

There's also a 31X5,5 mm roll bar, 4E0411305R, PR-2MA+T42 which is from the 8-cylinder diesel engine 4.0 L Unit 057.B

True. But for my understanding its not for 2006 model, although I'm pretty sure it will fit.

Edit; actually the 4.0TDI was discontinued in 2005, so it shouldn't been in my list at all.

Not a massive difference.

Not as big as I was expecting.

Be interested to see what difference it makes though.

Going by Tdum's level of motion sickness I would say not a lot :ROFL:

I guess it depends what you are after.

Personally I think it could be interesting to see how much better cornering the S8 anti-roll bars will give with the smaller, lighter engine, as its designed to fight the weight of V10, W12 or the heavier diesel engines. Less under-steer, and less tire wear would be welcome to me, driving mostly winding country roads.

The front is a simple pick-of and bolt-on operation, while the rear is a bit more challenging as you need to remove the trailing link on both sides, which also has an eccentric washer... :)

Stiffer at the front will give you more understeer, stiffer at the back will give more oversteer (or less understeer)