Looking for suspension and handling setup advice for a dual duty car

Hey all, first post here. Looking for advice on modifications for my car. Some background info - I drove an unmodified (other than brakes) Focus RS at the track for a few years - 4 weekends, 8 days total. I traded it in for a 2023 Audi RS3. I have 3 days on it so far. I am running much faster on it compared to the Focus RS now. The Focus was super stiff, and if anything I wanted to get coilovers to soften the suspension up. The RS3 has 3 damper settings, and all 3 are softer than the Focus' two settings.

The Audi RS3 has a staggered stock tire setup. 265/30/19s front and 245/35/19s rear. There are almost no track tires available in 265/35/19, so I decided to go with a square 265/35/18 setup. This means I'll have some more sidewall on the tires, and a slightly smaller (.5 inch) rear tire diameter.

I have been considering a few mods. More camber is better. I don't commute, so most of my tire wear is from track use. I need to replace my stock Bridgestone Potenza tires after 3 track days. I am going to try out Kumho V730s. The Potenza's wore at a very sharp angle on all the tread blocks, so I think more camber would be great. I'm trying to avoid excess NVH as well.

To increase camber, I'm considering 034 Camster Mounts and 034 Rear Control Arms. This will give me a fixed amount of Camber and Caster at the front, but I can adjust the rear.

Stock setup is 1.5 degrees of camber an almost 8 degrees of caster on the front, and 1.75 degrees of camber on the rear. This should put me at about 3 degrees of camber and 9 degrees of caster on the front, and I can adjust the rear to balance with the fixed front.

Another thing I'm considering is springs. I don't want to lower the car a lot. I think a 1 cm drop is fine, as well as a bit more stiffness. For that, I'm considering height adjustable springs. There are two options available for the 8Y RS3 - KW HAS and MSS. MSS offers a street and track version. The stock damping is really good IMO, so I don't think I need to go for coilovers right now.

Anti-roll bars are one more options, but I'm probably going to wait on that for now. I definitely think camber would be the biggest benefit. I'm not sure how much effect the springs will have, but some more stiffness and slight lowering would be welcome. I do lose traction going over a small hill (The Launch) at MSR Houston, which didn't happen in my Focus RS. I can just let off the gas though. Currently running fairly consistent 1:52s and 1:53s there completely stock on the Potenza Sport tires.

Any thoughts or advice? Thanks!

Sounds like a good plan. If you go to stiffer springs, those will make a bigger difference to body roll (and thus the need for negative camber) than sway bars would.

If you like the stock damping you don't want to go changing the spring rates very much. Though I'm assuming it's a semi active system, so it might have enough range to account for slightly increased spring rates. Depends on the tuning and the operating range of the dampers though. In any case I'd suggest to start with sway bars if you're generally happy with the suspension but just want a little bit less body roll. With the bonus that if one or both are adjustable that makes it super easy to tune the handling balance, which you can't do with springs and takes much more effort and possibly some compromise to do with alignment. More camber is certainly good and will probably improve tire wear. But the tires will always wear with a bit of a taper on the tread blocks, and trying to avoid increased nvh with high performance tires that get used to their limit is pretty much impossible.

Thanks! There is some body roll but it doesn't seem like a ton to me. I've read posts from people with the prior gen RS3 who actually went back to the stock swaybars after putting on springs, so I figured I would go with springs first. The softest damper setting is a bit softer than my preference for daily driving, so some more firmness wont hurt, especially with me switching to 18" wheels. 

I will keep my 19" wheels and probably put some good daily tires on them. I know the camber plates will likely increase NVH, but I'm not sure by how much. I am also not certain the springs will work with the camber plates, but I think they should.

Unfortunately neither MSS or KW publish their spring rates. I know ground control allows you to choose spring rates, but they haven't been able to confirm whether the kit they produced for the 8V works for the 8Y RS3.

Those camber plates shouldn't be too bad for NVH. The plates that have hard mounted pillow balls can be pretty bad though.

Have you talked to 034 about their springs?

https://www.034motorsport.com/dynamic-spring-set-8v5-audi-rs3-quattro-performance-lowering-springs.html

Is there a forum for RS3 owners? I'd start there.

My first thought is: does the RS3 share a chassis with a more common model from VW? If so, maybe you can find some suspension options from the VW world that could work for you.

My second thought is: isn't the suspension one of the few things that differentiates an RS3 from a regular S3? If so, then I'd be tempted to stick with the stock suspension for a while and see if I could optimize it with alignment and wheel/tire choice before starting to modify it significantly. In my experience, a simple alignment can make a big difference in handling. 

I did ask 034 about springs, but they don't have anything available yet. Plus, they usually just do fixed springs, so the drop would probably mean I am scraping on my driveway.

The RS3 does use the common MQB chassis, and a lot of aftermarket parts work, but most still need to be test fitted. A lot of RS3 are built for drag racing too, which is not what I am doing. The new Golf R is very similar other than the engine. Unfortunately both the new Golf R and RS3 are pretty recent releases, so there isn't of ton of info or parts to work off of. 

I do think I'll stick with the stock springs for a while. I got a 3 month shipping quote for the MSS springs anyway, so I might as well just test things out with just camber changes. I'm thinking -3 degrees of camber up front (as well as +1 degree of caster) and -2 degrees of camber in the rear. Tire calculators show my wheel switch will reduce the rear tire size a half inch, which should translate to a quarter inch drop in rear ride height, and of course a change in rake. I'm not sure if that really affects anything though.

First off, welcome to fun.

Second, I don't think I have the know-how to answer your questions directly, but here are some reference materials that I hope can prove useful:

• What Is Camber, Caster and Toe? | Handling Basics
• What Is An Anti-Roll Bar and How Does It Work? | Handling Basics
• Tilt! | How To Get Faster Lap Times by Adding Negative Camber
• How to pick the right anti-roll bar for your needs
• 10 Common Suspension Problems and How to Cure Them

I'm with you on the square tire setup and the camber mods.  Think hard about stiffer springs and whether you really need them.  Everybody thinks that a soft suspension is slow, but unless the car has trouble transferring weight or you're riding hard on the bumpstops in sustained corners, a soft suspension doesn't cost you anything and has some real advantages from a performance standpoint.  Once you start going to firmer springs you have to reconsider every other part of the suspension package- shock valving, roll bars, bushings, etc.  It all works together and the OEM engineers aren't as dumb as everyone seems to think.  Changing only one component of your suspension is like pulling the string on your sweater; next thing you know you're sitting naked in a pile of yarn.  Or something like that.

^ What he said. I went down the rabbit hole on my GTI. I gained about 2 seconds on a 110 second lap by doing camber plates, springs, sway bars. 

On my Cayman I installed adjustable front lower control arms, got a performance alignment and I'm calling it good.

Thanks again for all the advice and info. I've only read a couple of those articles, so I'll definitely go through the rest. I was originally considering the springs because I do have some spring softness and ride height to spare, and the wheels I'm switching to are a slight change in size. 034 and MSS seem pretty well regarding in terms of track use and making things work with stock suspension. But I do think I'll test the camber and wheels out first and see how it drives at the track before making further changes.

The RS3 is a great daily, so I am trying to not ruin that. My Focus RS wasn't great in that regard. My goal is definitely having a as good of a track car as possible, without sacrificing ride quality. I already dropped 6 seconds from my previous best in my Focus RS in just 3 days, so I really think my only need right now is more camber for more grip and less tire wear. And figuring out my alignment.