Front + Rear Sways or Just a Rear Sway

[Gberg888]

Hey everyone,

Should I be getting both sways done front and rear or just got with a rear sway bar?

Daily/Street Driven, may see a track day or two a year, but thats all.

[XLR8 Erik]

Good Afternoon! As you may have seen on another thread, we recently installed the APR front & rear stabilizer bars on their A3 (along with APR end links) and they are extremely happy with the upgrade. This is his first mod on the vehicle and it is a night and day difference. Currently, they are set in the softer setting and APR gives you the ability to change how soft or stiff the bars are. Feel free to PM me if you are interested in either one or both, and I would be more than happy to help! All APR products are in stock at our facility and we can get these sent out to you, or stop by for install, as soon as you would like!

[MikTip]

Both

Why?

The car is equipped from the factory with both.

Only doing the rear will off-set the OE balance of the front factory bar.

Replacing both bars with upgraded/stiffer bars will retain the "balance" of the OE setup, but be much stiffer. The car will track flat in corners. Much less body "roll"

https://axleaddict.com/auto-repair/A...r-for-your-car

[Oneill_1952]

Both,

I went with Eurocode bars, primarily for price & reviews.

Also I would suggest install either the 034 or Tyrolsport deadset kit in your front subframe while its removed.

I'm a street/daily highway driver and I have them on the soft setting and its corners like a mini cooper in the on/off ramps.

[Spinnetti]

Both

Why?

The car is equipped from the factory with both.

Only doing the rear will off-set the OE balance of the front factory bar.

Replacing both bars with upgraded/stiffer bars will retain the "balance" of the OE setup, but be much stiffer. The car will track flat in corners. Much less body "roll"

https://axleaddict.com/auto-repair/A...r-for-your-car

Yeah, but the factory balance sucks - understeers to death and won't rotate for sheet. I did just the rear on full stiff, added camber up front and put on 255's up front and it still doesn't corner for crap. Adding a front bar makes it flatter but doesn't contribute to fixing the understeer does it?

[MikTip]

Yeah, but the factory balance sucks - understeers to death and won't rotate for sheet. I did just the rear on full stiff, added camber up front and put on 255's up front and it still doesn't corner for crap. Adding a front bar makes it flatter but doesn't contribute to fixing the understeer does it?

VWOA does that for safety reasons...and its a mass produced vehicle for millions...where the vast majority dont want a stiff handling car!

The understeer is inherent to the caster and camber of the front suspension geometry.

[Chaoscreature]

I find it odd that the OP has 3 Porsches in his garage and is asking this question... if anyone knows about oversteer it's the owner of a pre-ESC 911

OP, are you looking to decrease oversteer or just flatten the car out around corners?
If you post a little bit more about what you want to change (and not change) in your vehicle dynamics we can help push you in the right direction.

[MikTip]

Yeah, but the factory balance sucks - understeers to death and won't rotate for sheet. I did just the rear on full stiff, added camber up front and put on 255's up front and it still doesn't corner for crap. Adding a front bar makes it flatter but doesn't contribute to fixing the understeer does it?

Have you looked into this:



Up to 2.0 ° extra dynamic positive caster
Supertrac anti-lift geometry for more traction!
Additional ~0.5° of negative camber

Or this:



https://www.ecstuning.com/b-superpro.../spf4178k~spr/

For camber:



Offering an additional .8° of fixed camber adjustment both negative and positive depending on your goals. Improve your vehicles handling balance while reducing the dreaded understeer

[Spinnetti]

Thanks.. I've got camber plates and fear if I go any more I'll have terrible tire wear. This platform is definitely the worst handling Audi I've had (6 so far) but could be down to a simple alignment. I might just need less toe-in out back. Last place I took it for alignment wouldn't do it to my specs so I need to find a different shop. Even my old GLI handled much better oddly. Just feels like the front end is overwhelmed. Its great in day to day driving and I love it in general just not at the limit. Maybe I'm asking too much of it.

Chaos - lols on the 911 - there's something that'll get your attention faster than a Mustang leaving a cars and coffee!

[Chaoscreature]

Those Supalloy arms certainly look like a nice bit of kit :)

I don't think the car needs any more caster though, in fact it could probably do with less unless you are running super high speeds.
IMO one of the big issues is there is just too much compliance in a lot of the suspension bushings. The front control arm, rear position bushing design is garbage. SuperPro and Powerflex both have interesting takes on a Urethane Monoball but I question the durability of that solution.
It's odd that the steering feel is so numb. Even though the rack is electric, it is still a mechanical device. It's solidly mounted, no rubber in the Tie Rods. I'm wondering if there is a rag-joint or something absorbing vibration into the steering wheel. I can't "feel" the road with my hands and need the tires and my butt to do all the communication.

Spinetti,
I am surprised your shop wouldn't set the alignment where you wanted it. The place I went to set my front toe right where I wanted it. Zero toe in front and +.05deg per side in the rear. I just had them match the camber in the rear to the front.
Funny you said that your GLI handled better. I moved into the A3 from a MK6 Jetta and with a few suspension/chassis tweaks the Jetta was very tossable!
What shocks are you running?

[rex_racer]

Hey everyone,

Should I be getting both sways done front and rear or just got with a rear sway bar?

Daily/Street Driven, may see a track day or two a year, but thats all.

What are the other mods on the car? If you just want the car to be fun, then get a rear bar. if you're looking to set consistent and fast lap times, Big Front Bar and the correct alignment to match. It won't be fun, but it'll be fast.

[Chaoscreature]

Rex-Racer,
I think you got that backwards, and what kind of "correct" alignment would you recommend?

[TheContrarian]

Don't forget the impact of tires, what are you using?

As far as the platform, it did just win one lap of america (Audi TT RS).

[Gberg888]

Yes I have 3 porsches and I mostly track the boxster. The S3 isnt in my garage yet but by the end of the month it will most likely be there provided i can find the right one.

As for what I want, a fun daily is the answer that can handle a track day or 2 a year. Not looking to set lap times, just get better at driving and have some fun while Im at it!

[rex_racer]

Rex-Racer,
I think you got that backwards, and what kind of "correct" alignment would you recommend?

Not backwards at all. With all setups alignment must match the setup of the car. If you can't maintain the contact patch on the front tire, you'll simply overload the tire and do nothing to increase front end grip. An oversized rear bar can and will overload the outside front. The 8V chassis has a highly adjustable rear end. It doesn't take much to get the rear end to rotate. Simple camber and toe adjustments go a long ways.

[Chaoscreature]

Gberg888,

For your first track session with a new car, just take it to the track stock. Toss it around and see what you think. After a day at the track you should have a better idea of what you like/dislike about the chassis and can make educated decisions about what to improve.

Rex_racer,
Are you talking about a drag racing setup?
If you are talking about an AX or DE type of setup, please let me know what alignment values you used to make an otherwise stock S3 rotate, let alone one with an upgraded front sway bar only.

[Gberg888]

Gberg888,

For your first track session with a new car, just take it to the track stock. Toss it around and see what you think. After a day at the track you should have a better idea of what you like/dislike about the chassis and can make educated decisions about what to improve.

Yes! I will do exactly that!

[rex_racer]

Are you talking about a drag racing setup?
If you are talking about an AX or DE type of setup, please let me know what alignment values you used to make an otherwise stock S3 rotate, let alone one with an upgraded front sway bar only.

This is specifically for AX and DE. I should have clarified that driving style will also need to be adjusted to suit the chassis change. On a stock chassis, simply bringing the toe to 0 and reducing camber to -1 or less will already let the car start to rotate. At this point the front end is still rolling over and getting out of its ideal camber range. A front sway maintains the front end composure and keeps the tire upright and gripping. Further adjustment to the rear toe, -1/16 on up to -3/16 depending on use and driver ability will retain turn in and allow rotation to continue.
Oversizing the rear bar will actually overload the front outer tire, taking you out of the ideal camber range and contributing to steady state understeer.

This chassis is really not as bad as everyone makes it out to be. With proper setup work the chassis is quite decent, really only needs a large front bar and alignment.

[Spinnetti]

This is specifically for AX and DE. I should have clarified that driving style will also need to be adjusted to suit the chassis change. On a stock chassis, simply bringing the toe to 0 and reducing camber to -1 or less will already let the car start to rotate. At this point the front end is still rolling over and getting out of its ideal camber range. A front sway maintains the front end composure and keeps the tire upright and gripping. Further adjustment to the rear toe, -1/16 on up to -3/16 depending on use and driver ability will retain turn in and allow rotation to continue.
Oversizing the rear bar will actually overload the front outer tire, taking you out of the ideal camber range and contributing to steady state understeer.

This chassis is really not as bad as everyone makes it out to be. With proper setup work the chassis is quite decent, really only needs a large front bar and alignment.

Hmm... this doesn't jibe as a front bar increases understeer all else held constant, and there isn't enough roll to overwhelm the camber. Rear toe will def. help and that's up next for me, but I'm getting zero roll over up front and reduced rear camber to less than stock in the rear, with -3 or so up front and running the 255/235 stagger, and still no bueno.

[Chaoscreature]

Yup, gotta agree with Spinnetti. This isn't jiving.

Camber in the front is not adjustable on a stock car, so reducing camber isn't possible. From the factory front camber is about -1.2 degrees. At best you can shift the subframe to try and balance out the camber left/right.
Even if you could reduce the camber in the front, that's the opposite of what you want for track use. 1.2 degrees of camber is not enough to prevent the tires from rolling over on themselves and shredding the outside shoulder of the tire.

Every driver is different and if this setup works well for rex_racer that's great, but it's not the direction I went or would recommend to others.

What hasn't been discussed yet is tire pressure. With stock suspension geometry you can run the rear tires a few (or more than a few) psi higher than the front tires to reduce the traction in the rear which will allow the back end to step out more willingly.

[rex_racer]

You've misunderstood me, front camber would be maxed out on the stock suspension, ie equalized. Rear camber is what gets reduced. For a modified car, I come from the big rear bar camp, have setup many autox/track cars this way. The fastest BRB setup always seemed to be on the ragged edge. I also started seeing through data and feel that the front was just not right, even with plenty of camber. Tested with multiple rear bars and saw what the oversized rear bar was doing, overloading the outer front. Looking at other championship winning setups I opted to try their way, a big front bar and associated adjustments. The drive itself was boring, but the car put down better times and was much easier to drive. Reviewed my findings with other champs utilizing the same suspension setup and they all said the same. Started setting up cars with the same suspension design and the result was always the same, boring to drive, consistent, more grip and lower lap times.

As other chassis designers and setup engineers have said, you should focus on maximizing the front end grip before trying to loosen up the rear. If the front end is standing on one outer tire it has less grip than if both tires are contributing. Whether by spring or bar, the front needs more roll control.

[TheContrarian]

I just autocrossed my stock RS3 yesterday and the car rotates just fine. In a slalom I can get the rear end coming around nicely even when the course is tight. This has been the experience of other RS3 owners and those experienced autocrossers also thought a front bar with a stock rear would be the way to go.

[Spinnetti]

Hmm.

My front camber is maxxed out at -3 (as far as I'm going) and rear camber is reduced, plus wide tires, wide wheels, reverse stagger and the front tires are not rolling over....... Car & Driver said of the RS3 the same thing I'm seeing. Maybe its just alignment.

[Chaoscreature]

A stock RS3 is a different animal than a stock S3.
The reverse staggered wheels alone will have a huge impact on vehicle neutrality. The extra power and more aggressive haldex tuning should also make it easier to rotate the RS3 around a corner with on-throttle oversteer.

Of course for me this is all conjecture. I have only driven my A3, so it's completely plausible that the S3 is an oversteering drift monster from the factory and I am completely out of line here :)

[stevwang]

Yeah, but the factory balance sucks - understeers to death and won't rotate for sheet. I did just the rear on full stiff, added camber up front and put on 255's up front and it still doesn't corner for crap. Adding a front bar makes it flatter but doesn't contribute to fixing the understeer does it?

Agree with this 100%

Sent from my LM-G710 using Tapatalk

[diztek]

i like it with just the rear sway upgrade. more over steer.

[R.Cade]

In what conditions are you guys seeing all this under steer? I've only got 3 hours of track time on the S3 so far, but thought the turn in was excellent. I'm running PS4S 255's all four corners.

[Spinnetti]

In what conditions are you guys seeing all this under steer? I've only got 3 hours of track time on the S3 so far, but thought the turn in was excellent. I'm running PS4S 255's all four corners.

One thing to clarify is at the limit handling on the track, street driving and autocross all require different setups. My focus for this car is the street as I have a dedicated race car. On the street, I like to toss the car into a turn while trail braking, the rear drifts out then you nail the gas pulling the car in a nice gentle drift. All of my cars are modified. My Lexus will do it, my R8 will do it my (3) A4's would do it, the Bug would do it, my GLI would do it etc. (all except the R8 and Lexus have stiffer rear bars).. the S3 stubbornly refuses. It just understeers. I'll get it figured out eventually but its just been highly resistant to anything but understeer except in the rain - at race track speeds, I'm sure its a different story. Its not the total grip I care about, its the balance between front and rear. Tempted to put the battery in the trunk too, but feeling lazy. All my previous Audi's handled great with a bit of tuning. Its not just me saying this - read any review ever; I never understood the feedback about Audi handling, but now I get it - at least on this platform.