Size difference between Rear Sway Bar between Sport and Non-Sport Suspension?

[GetBoosted84]

I was searching around but couldn't find any info on this... does anyone know if the rear sway bar is different between the sport and non-sport A4's? I know the front ones are but I cannot find any details on the rear ones.

Any input would be greatly appreciated.

[JW Spencer]

The A4 wiki above is very informative, although it is not entirely clear between sport and non sport of later years.

[GetBoosted84]

Yeah, I was trying to find something concrete but came up with nothing.

Here's the wiki page (checked there too) for future searches: http://www.audizine.com/wiki/index.p..._A4#Suspension

[gmx]

I'm not sure about stock.
But sport swaybars are the same as S4 units.

[GetBoosted84]

I'm not sure about stock.
But sport swaybars are the same as S4 units.

Good to know... thanks!

Anyone else know some details about the stock non-sport versus sport rear sway bar?

[FNK]

Stock rear 12.5 mm
Stock sport/S4 rear 15 mm

I am currently sanding to repaint S4 Swaybars, I'll let you know if theres a difference... because on paper it's only 10%

[GetBoosted84]

Awesome thanks very much for the info!

[somebody5788]

I wouldn't waste my money on the sport rear. Neuspeed rear/ sport front. Not too harsh but gives the car balance accompanied with some good shocks/springs or coilovers.

However since I want to upgrade anyone can buy my sport rear sway.

[FNK]

I wouldn't waste my money on the sport rear. Neuspeed rear/ sport front. Not too harsh but gives the car balance accompanied with some good shocks/springs or coilovers.

However since I want to upgrade anyone can buy my sport rear sway.

Any difference between STD vs Sport? Less understeerrrrr?

[GetBoosted84]

I wouldn't waste my money on the sport rear. Neuspeed rear/ sport front. Not too harsh but gives the car balance accompanied with some good shocks/springs or coilovers.

However since I want to upgrade anyone can buy my sport rear sway.

Neuspeed is the next step. I just got a set of sport sways for free so I figured it would be a good upgrade until I find a deal on a neuspeed or hotchkis setup.

[FNK]

Off topic : I upgraded my summer tires from Michelin Hydroedge to Bridgestone Poleposition S-03, and the typical understeer is gone! The tires dont give up no mater what, Insane! Received H&R sport spring... long winter ahead, kick ass car next summer! Add to this, Sport swaybar... understeer will be as eliminated as possible!

[gmx]

Off topic : I upgraded my summer tires from Michelin Hydroedge to Bridgestone Poleposition S-03, and the typical understeer is gone! The tires dont give up no mater what, Insane! Received H&R sport spring... long winter ahead, kick ass car next summer! Add to this, Sport swaybar... understeer will be as eliminated as possible!

What do they do at the limit?
What pressures are you running?

[FNK]

IIRC it was 15mm non and 17mm for the sport.

Nope, just measued the S4 swaybar, 15mm +0 -0.2mm
I remember measuring the A4 non-sport and it was quite small, 12mm in fact. maybe smaller, the tolerance seems to be quite high on this part.

[somebody5788]

Any difference between STD vs Sport? Less understeerrrrr?

I have always had a sport one so I wouldnt know. However it's just not good enough.

[FNK]

Ok thanks

[GetBoosted84]

Non-sport sways are not helping understeer. I have those on my car currently. Hopefully the sport ones will yield some help with that.

[biketsai]

Nope, just measued the S4 swaybar, 15mm +0 -0.2mm
I remember measuring the A4 non-sport and it was quite small, 12mm in fact. maybe smaller, the tolerance seems to be quite high on this part.

Gotcha, glad you were able to clear that up.

[Kronic Budz]

What is the best size rear bar on a 2.8 with a stock non sport front bar? I was thinking 19mm for rear and the 22mm for rear if running sport front bar?

I'm going for less understeer and more stiffness in chassis but don't want oversteer

[GetBoosted84]

What is the best size rear bar on a 2.8 with a stock non sport front bar? I was thinking 19mm for rear and the 22mm for rear if running sport front bar?

I'm going for less understeer and more stiffness in chassis but don't want oversteer

They put them as a set for a reason. If you don't use a matched set then you can run into a problem of either too much oversteer or understeer depending on which one you leave stock and which one you upgrade.

Also what do you mean by, "19mm for rear and the 22mm for rear"... there is only one sway bar in the rear.

[Kronic Budz]

They put them as a set for a reason. If you don't use a matched set then you can run into a problem of either too much oversteer or understeer depending on which one you leave stock and which one you upgrade.

Also what do you mean by, "19mm for rear and the 22mm for rear"... there is only one sway bar in the rear.

I mean that if I were to leave my stock non sport front bar in, that I would get a 19mm nothing bigger to not let the rear bar be dominate over the front bar and produce oversteer. BUT, if I could find a s4/a4 front sport bar I could go with a 21-22 mm rear bar and be somewhat balanced out because from what I hear the sport/s4 front bar is pretty firm compared to non sport front bar.

I don't want to get the kit really because 35mm front bar is just overkill for a dd. A 29mm stock bar is already quite large, the rear bars are just pinner...

[FNK]

Some report REAR bar over 19mm have a tendency to crack the subframe. RS4 use 19mm

[Shhmaudi]

Who loves their 19mm neuspeed rear sway?

[Kronic Budz]

Some report REAR bar over 19mm have a tendency to crack the subframe. RS4 use 19mm

That's why it's recommended to get the subframe reinforcement brackets so that doesn't happen.

[FNK]

Rear S4 sway bar, with Adjustable Sway Bar End Links to shorten the leverage, thus increasing in the stiffness
http://www.audizine.com/forum/showth...hipped-Special

[treitzboost]

the s4 sway bar makes a big difference in the back. The front doesnt do much. I love mine.

[Kronic Budz]

Since a sport/s4 rear bar is 20% larger in diameter. 15mm vs 12.5mm.
Does that mean the sport bar is at least 30-40% stiffer?

^^^ this guy is saying it made a big difference

[FNK]

Shear stress,
I don't have the Inertia formula here, but a partial equation give me 20% stiffer swaybar on the S4

[034Motorsport]

I wouldn't bother upgrading to the S4/Sport bar if you don't already have it. Just man up and grab a Neuspeed rear or an H-Sport rear (and stay away from the fronts), along with some upgraded end links. Drastic handling difference, far less understeer, and the swaybar end links will sharpen up response time even more.

I run the H-sport 22mm, in the neutral position (closer to the front of the sway bar) on my S4. Much of this depends on your driving style and suspension setup, but we run the stock front swaybar on our A4 Time Attack race car (one of the fastest B5's in the world) just to give you an idea. A front bar might help you at 120mph, but honestly, who goes that fast very often? The rear bar will help your sweet spot, from low to medium-high speeds.

[GetBoosted84]

What will probably make more of a difference in terms of cornering speeds would be changing over to a 4:1 center diff IMO. I have a Stassis unit that I'm thinking about selling if you are interested.