Upgrade the rear ARB

[Jason Burchell]

Hi all, I have a stage 3 S4, suspension wise it has H&R springs, and bilstein dampers.
It can understeer at times and I think that a thicker rear ARB would cure it.
I asked someone to measure the thickness of the bars fitted the other day.
He told me I have 30mm front and 15mm rear.
I have a 1998 S4
I'm thinking I would need a 18-22 mm rear sway bar. However I'm not sure and I'm also unsure of what gets fitted on a similar year rs4 and what thickness they are.
Audi, although helpful are not helping with sourcing part numbers because I don't have the reg or vin of an RS4.
Does anyone have any advice to help or maybe know of a good after market solution. I have no intention to replace the front one. Just stiffer rear but not so stiff that it faces the wrong way on me.

 

[aragorn]

RS4 also had a 15mm, though there was a rare "Clubsport" option that was 17mm.

Nuespeed i think do a decent 19mm rear bar with subframe reinforcement brackets.

 

[Jason Burchell]

Neuspeed. Any idea who in the U.K. Retails them?

 

[Bradderz_1988]

Awesome gti

 

[Bradderz_1988]

https://www.awesomegti.com/shop-by-brand/neuspeed/neuspeed-rear-anti-roll-bar-a4-s4-b5-4wd-19mm/

 

[Bradderz_1988]

Or they do the thicker 034 one

https://www.awesomegti.com/shop-by-...solid-rear-sway-bar-25-4mm-audi-a4-s4-rs4-b5/

 

[adamss24]

Best would be to get the Hotchis rear ARB as it comes with subframe strenghtening brackets- mandatory as the subframe breaks without them...

 

[Bradderz_1988]

The 034 one does if you select the option.

 

[Jason Burchell]

Oh! So many choices. What one does the job the way I want it. Hmm. Do they come with a 30mm front as standard?

 

[Bradderz_1988]

Oh! So many choices. What one does the job the way I want it. Hmm. Do they come with a 30mm front as standard?

Don't touch the front roll bar the stock one is fine coupled with an upgraded rear bar.

 

[Jason Burchell]

I don't plan to do the front one.
Information on the sizes used across the range front and rear would help make an educated guess.

 

[VAG-Slag]

Will be keen to see if a rear ARB does solve your under-steer issues...

I've just bought a stage 3 S4, currently on completely standard suspension... Although rather wallowy and boat like, I was actually surprised at the lack of under-steer! . . I have some Koni coilovers waiting to go on though, however I wonder whether the stiffer set up might actually induce more under-steer in poor conditions?

 

[Jason Burchell]

There's a thought. If mine had old knackered suspension I would go for Sachs springs and shocks all round.
Did it on my TT and put a golf 4motion rARB on and it's lovely. Holds a much better line and never skips or bounces.

 

[S4_dan]

Have you had a 4 wheel alignment check?

I had my B6 quattro done and it made a big improvement on the whole handling.

 

[Jason Burchell]

Have you had a 4 wheel alignment check?

I had my B6 quattro done and it made a big improvement on the whole handling.

Hmm. I will have to get it out on a hunter tracker.

 

[VAG-Slag]

There's a thought. If mine had old knackered suspension I would go for Sachs springs and shocks all round.
Did it on my TT and put a golf 4motion rARB on and it's lovely. Holds a much better line and never skips or bounces.

Well the Koni's I have are not only height adjustable but damper adjustable too, so I'm hoping they should be fairly versatile!..

And if you've not had your wheel alignment checked since fitting the lowering spring it'll almost certainly need adjustment...

 

[Ali_cat]

Hi guys.

Although I didn't have an S4 I had a tqs I ran front and rear h&r roll bars. Made a massive difference IMO. Much stiffer and more compliant round the corners.

I have a pair of front and rear for sale, but I'll split *cough cough* Also I had neuspeed brackets on the frame which are necessary for fitting. Drop me a PM if you're interested in buying.

 

[aragorn]

the neuspeed bar is big enough, and comes with the brackets. 19mm is more than twice as stiff as the stock 15mm bar.

Remember, ARB's reduce mechanical grip. So in effect, your reducing rear end grip by fitting a larger rear bar, but in the process giving the car a more neutral handling characteristic.

I think anything larger than 19mm would need a larger front as well to keep the balance right, but fitting larger front and a matching huge rear isnt a good idea IMO for a road car.

 

[Broken Byzan]

17mm makes a great difference, I can only imagine the 19mm is fantastic

 

[Kingfisher]

Never did this on the B5 but did on my B6 S Line Quattro. I put on the B6 S4 rear bar ( think it was 18mms ?? instead of the 16mms it came with )
Very worth while so I reckon it is well worth doing on the B5.
Loads of evidence that the sub frame will crack if not reinforced.