Without a doubt the new Audi B9 S4 is a marvel of engineering. Audi have improved upon the B8 S4 with a new turbocharged V6 replacing the previous supercharged V6, giving the B9 and extra 21 hp and 44 lb-ft of torque for a total of 354 hp and 369 lb-ft of torque. It also over 250lbs lighter than the previous generation so the power is even more noticeable. Furthermore, the all-wheel-drive system has been improved for even better road holding and responsiveness. However, we’re enthusiasts. To us cars are not complete when we get them from the dealership, they are instead a canvas onto which we will impart our personality and our ambitions. We want our cars to look better, corner faster, and accelerate harder because we are not the type to settle for ordinary.
We’d like to preface that this is not a complete article, the B9 S4 is still relatively new and unfortunately does not have a large amount of mods available for it. Instead this will be a living document where we will add new parts and update information as it becomes available.
In this article we will also be going over parts the S4 shares with the B9 A4 as well as some parts unique to the A4. We will be sure to go over what will and won’t fit both models and why so you aren’t left in the dark.
Wheels:
For any enthusiast wheels are a go-to first mod. Factory wheels are generally very heavy, far too thin, and sometimes they’re even offensively ugly. The advantages of getting yourself some aftermarket wheels are a better weight to size ratio, greater width to fit wider tires, and being able to choose the exact style and size you want. Luckily the new B9 S4 has a very similar chassis to the previous B8/B8.5 so your favorite wheel and offset configurations will still fit and look good, although the more precise flush fitments will need to be more carefully measured. Like the previous model you will be looking at wheels between 8.5 and 9.5 inch widths and 19 or 20 inch diameter. Your sweet spot for offsets will be between ET25 and ET45 depending on what width you decide on and how flush you want the fitment (for help choosing you can always call and speak to one of our Mod Experts). Because the B9 A4 wheelbase, track, and body shape are shared (minus aesthetic pieces) all wheels and fitments mentioned will fit both the A4 and the S4.
Please note that some of the wheel photos below will be on the B8/B8.5 because we could not find photos of them on the B9. If you have a B9 with any of the wheels mentioned below we’d love to add it to this article so others can see what they look like on a B9. Please submit your photos to Sales@Modbargains.com with a the subject line being “Photos of Audi B9 with [your wheels brand and model]”.
HRE
HRE is a very well known and respected wheel company who put out very high quality wheels with very classy designs. Our recommendations come from their FlowForm line of wheels which are rotary forged for high strength and low weight. When you buy a set of HRE wheels you know you’re buying a wheel that is going to be light, durable, and look amazing.
FF01
The FF01 is a split seven-spoke design that goes well with the Audi’s European styling. The mesh design has a distinct presence but leaves enough room to see the brakes.
FF04
The FF04 is a wider split five spoke design that looks very aggressive and shows off the large brakes on the S4 quite nicely. If you want a more intimidating look then these would be a great choice.
FF15
The FF15 is a 15 spoke fin style wheel with wide fins so you can still see the big brakes behind the wheel but you also have more substance to the wheel itself.
VMR
VMR is a very well known brand in the Euro market and for good reason given their utilization of flow forming and attractive designs. Their wheel designs work well with the S4 and give it a very aggressive aesthetic.
V710/FF
The V710FF is a split seven-spoke mesh wheel that is light weight and strong due to its flow form construction. Alternatively if you like the design but don’t mind a cast wheel you could also opt for the normal cast V710.
V803
The V803 features a widely spaced split five-spoke design which really shows off the big brakes on the S4. The wheel is flow formed so you won’t be adding too much rotating mass to your vehicle.
V801
The V801 is a flow formed split ten-spoke mesh design which gives a striking look to the S4. It’s a less “Euro” design than the others featured here and definitely has a unique aesthetic to it.
Avant Garde
Avant Garde is a very prestigious and respected brand in the enthusiast community. Avant Garde earned their reputation for quality through their amazing fitments and beautiful finishes. If you want show quality wheels with superb designs then Avant Garde is a great buy!
M590
One of Avant Garde’s most popular designs is the M590. It is a split seven-spoke mesh design with a satin silver finish. They are low pressure cast so they’re lighter and stronger than gravity cast wheels but not quite as strong as a flow formed wheel would be. However if you’re looking for excellent show wheels then these are a great pick.
M610
The M610 is part of Avant Garde’s “Advanced Rim Technology” or A.R.T lineup. It is made using flow forming (generically referred to as “rotary forming”) so the resulting wheel is very strong and lightweight (more so than low pressure casting). The design is reminiscent of the M590 so if you want a similar spoke layout but with a more performance oriented construction then the M610 is a solid buy.
M621
If you’re looking for a very unique design the M621 is a great choice. It’s a ten-spoke directional design that goes very well with Audi body lines and the spokes are widely spaced to show of your big calipers as well.
Forgestar
No list would be complete without mentioning Forgestar. Forgestar wheels are, like many other brands, very strong and light thanks to being flow formed. However, Forgestar allows you to pick your own offsets when you order them, giving you the freedom to pick your perfect fitment (our Mod Experts can always help for those unsure of what fitments they need).
F14
The Forgestar F14, named after the fighter aircraft piloted by Tom Cruise in the hit 1986 action flick “Top Gun” (not really but we like to imagine they are), is a striking split seven-spoke design that compliments the B9’s sporty body lines. The spokes on this wheel are narrower which give it a sharper and more aggressive look than some other split seven-spoke wheels mentioned in this article. They are flow formed and offer a wide variety of colors so they’re the number 1 pick for many enthusiasts for both track days and shows.
CF5V
The CF5V (unfortunately not named after a fighter jet) is a split five-spoke design that is great for showing off those big brakes on the S4. Flow form construction once again means that these wheels are light and strong so you can take them to the track when you’re not turning heads at the shows.
305Forged
305Forged is a wheel manufacturer that has handled the production of wheels for many big brands in the past, but recently they decided to get into designing their own models. Their Flow Tech series is comprised of beautifully designed flow formed wheels that are lightweight, look great, and don’t break the bank.
FT-101
The FT-101 wheels are a split five-spoke design that looks great on Euro vehicles. Its wide spokes show off big brakes well and you can get a great concavity on them if you go wide enough with low offsets.
FT-102
The FT-102 is another split seven-spoke design with interestingly stepped spokes to give a bit of depth to the look and draw focus to the wheels. This design unfortunately does not have quite as much concavity to it so if you’re looking for a deep concave you’ll want to consider other options.
FT-107
The FT-107 is a very unique design that is what could be called a branching split five-spoke. The sharp lines and angles give it a very aggressive look that most people will not have seen the like of before. If you like the design these wheels will really help your car stand out.
Wheels…(Current)
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Tires:
When you buy a high performance sports sedan you should expect it to not just have impressive power delivery, it should also handle well and corner quickly (you didn’t buy a muscle car). The number one component that affects your car’s handling capabilities is your tires. Forget lowering springs or coilovers for a minute (we’ll get to those), your tires are the only component that can directly affect your car’s road holding capabilities because they are the only thing that connects you to the road. The B9 S4 comes standard with Pirelli P Zero (PZ4) tires which admittedly are very good tires, but if you want the absolute best out of your S4 there are better options available. If you own an A4 that came with factory all season tires then upgrading your tires is even more beneficial and you will see a notable difference in handling. We do highly recommend a spring/coilover upgrade with performance tires to reduce body roll and make hard cornering feel more planted.
Summer Performance
Michelin Pilot Sport 4S – (Treadwear: 300 / Traction: AA / Temperature: A)
If you want the absolute best Max Performance Summer Tire then look no further than the Michelin Pilot Sport 4S (PS4S). The PS4S is Michelin’s successor to the Pilot Super Sport (PSS). The PSS was already a legend in the automotive industry and the benchmark by which all other Max Performance Summer Tires have been judged. With the PS4S they wanted to improve upon as many aspects of the PSS as possible, and they succeeded. The PS4S achieved notable improvements in wet braking, wet handling, dry handling, tread life, and even road noise. For more info on the PS4S you can check out our recent blog article where we break down what makes it such a great tire. If you’re more in the mood to sit back and watch a video you can check out our episode of Know Your Mods all about the PS4S.
Nitto – NT555G2 – (Treadwear: 320 / Traction: AA / Temperature: A)
Like the PS4S to the PSS, the NT555G2 is the evolution of Nitto’s NT555 Ultra High Performance Summer Tire. They improved traction, grip, and stability with this new iteration and reestablished themselves as the dominant power in the Ultra High Performance Summer category. If you’re looking for great dry performance but occasionally need to drive in rainy conditions the NT555G2 is an excellent choice.
Hankook – Ventus V12 Evo2 – (Treadwear: 320 / Traction: AA / Temperature: A)
The Ventus V12 Evo2 from Hankook is a great pick if you want a Max Performance Summer tire but you don’t want to break the bank on the PS4S. The V12 Evo2 has excellent grip and responsive handling with its downside being a lack of wet traction and much more noticeable road noise. However, if you plan to drive your S4 in the wet/snow during winter then these tires are a great option because it leaves you a lot more money to spend on winter tires. For instance if you are using the stock wheels with a 245/35-19 tire then getting a set of the Hankooks would save you over $450 vs buying the PS4S.
All Season
Continental – DWS 06 – (Treadwear: 560 / Traction: AA / Temperature: A)
For those of you who live where it rains quite a bit and summer performance tires are a bit of a silly purchase, the Continental DWS 06 is a perfect choice. These tires are All-Season Ultra High Performance so you get impressive dry traction while still being able to handle rain and light snow. As an added bonus these tires will last significantly longer than summer tires because they are made from a harder compound.
Terminology
Understanding UTQG Treadwear, Traction, and Temperature Ratings: (credit Mark D.)
Treadwear – A standardized test of how quickly a tire wears down over 7200 miles (with tire rotations, alignment checks, and pressure checks every 400 miles). The tire is tested against a standardized “Course Monitoring Tire” and its grade is assigned based on the relative wear. 100 would indicate it would last as long as the test tire, while 200 would indicate that it would last twice as long as the Course Monitoring Tire. This still only tells us so much because we don’t know exactly how long the “Course Monitoring Tire” lasts. Also, treadwear is subject to some interpretation as the wear experienced on the tire being tested is open to interpretation by the manufacturer. In general though, the higher the number, the longer it will last.
Traction – UTQG traction tests do not evaluate traction in relation to dry braking, dry cornering, wet cornering, or high speed hydroplaning resistance. The test is simply a representation of the tire’s ability to stop on wet pavement as the tire skids. So this test really only applies to those without ABS in wet conditions.
Temperature – The temperature grades are a scale that indicates a tire’s ability to resist the heat buildup produced by speed. A is good enough for speeds over 115 mph, B is between 100-115 mph, and C is between 85-100 mph.
No matter what tire you decide to buy, we recommend not letting the UTQG Rating have much influence on your purchase (consider that all tires mentioned here have “AA” traction and “A” temp ratings, but have completely different performance).
Tires…(Current)
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Suspension/Chassis:
Suspension and chassis mods are the best way to change the look and feel of your car. A car can be fast and corner well but with factory suspension and bracing you’ll have body flex and roll that really detracts from the experience. If you lower your car and add chassis bracing/bushing upgrades it can drastically improve the feel of your car overall.
Lowering Springs
One of the first mods most enthusiasts look for with a new car is lowering springs. They are always a great purchase because they give you reduced body roll, a more responsive ride, and they get rid of the repulsive factory wheel gap. Furthermore they are very affordable so you don’t have to break the bank to dramatically change look and feel of your car.
H&R – 50357
H&R is one of the most well respected names in aftermarket suspension. They are (at the time of this article) the first to develop springs for the B9 S4. H&R Springs have a reputation for excellent build quality and tuning of their products to their intended application. These lowering springs will give you about .8 inches of lowering front and back from the stock S4 suspension (roughly 1.6 inches from stock A4 w/o sport suspension) so your car will look sleek and sexy. The spring rates are also increased on the H&Rs so you get flatter cornering and a mildly firmer and more responsive ride.
Eibach – Pro-Kit: E10-15-023-02-22 (FWD A4 Only)
Eibach – Sportline Kit: E20-15-023-02-22 (FWD A4 Only)
Eibach currently has a couple sets of lowering springs available for the FWD A4 but states that these will not fit the AWD A4/S4. The Pro-Kit will give you approximately 1.2 inches of lowering front and back from the stock non-sport A4 suspension (meaning roughly .4 inches from the sport suspension). If you’re looking for a bit more lowering the Sportline Kit will give you 1.8″ lowering in the front and 1.6″ lowering in the rear rear (1″ lowering front, .8″ lowering rear from sport suspension). Generally Eibach is pretty quick about developing springs for newer cars so hopefully we’ll see them released for the Quattro and S models soon.
KW H.A.S – 253100xx (FWD A4 Only)
Do you want height adjustability but don’t want to spend the money on coilovers? KW Automotive developed the H.A.S. kit for just that reason. This kit utilizes your factory dampers and comes with four lowering springs, bump stops, and four adjustable perches. What this means is that you can adjust the perches to raise and lower your vehicle without having to buy coilovers or sacrifice your Electronic Dampening if your car came equipped with it.
Coilovers
Coilovers are the next level of suspension upgrades. The benefits of a coilover are that you can finely tune your ride height to exactly what you desire. Furthermore the dampers on the coilovers are built to match the springs so you get the two working together properly instead of worrying about if your lowering spring’s rates are too high for your oem dampers. Additionally, you will often get dampening adjustability on coilovers which allows you to finely tune the ride and responsiveness of the coils.
KW – 352100xx (FWD A4 Only)
Currently the only coilover kit we recommend for the B9 is the KW V3. KW is one of the most trusted brands in the world when it comes to aftermarket suspension so you can trust the KW V3 to be excellent build quality and superb functionality. With the kit you can adjust both your height and your dampening levels to get your car looking and feeling exactly how you want. The kit even comes with EDC cancellation modules so you can safely disable your electronic dampening without causing and annoying check engine lights or other complications. Currently they are only available for the FWD A4 but the AWD version is in development and should be available soon.
BC Racing – In Development
The BC BR coilover line is a bit of a favorite here at ModBargains due to its excellent value and functionality. They have great build quality and a wide selection of features such as dampening adjustment, customizable spring rates, aluminum camber plates, and preload adjustability. Despite having such a wide range of features BC prices their coilover very reasonably (generally between $1000-$1200), so when these coils do come out for the A4/S4 they are sure to be one of the best in terms of value for money.
Sway Bars
Beyond lowering springs and coilovers there are other great ways to improve the feel of your car. Sway bars are one of the most cost effective ways of reducing body roll and improving traction for your inner wheels. A good sway bar can make a huge difference in how your car feels in the corners.
034 Motorsport rear sway bar – 034-402-1010
With the factory sway bars on the A4/S4 the car will be balanced for a bit of understeer. This is done because understeer is safe and easy to correct for the unskilled driver. Understeer is also generally hated by enthusiasts because it is painfully boring and makes your car feel less responsive. To counteract the factory understeer we recommend fitting a thicker rear sway bar. The dynamic+ adjustable rear sway bar from 034 Motorsport is a great option because you get a significantly thicker sway bar with the option of adjusting it even stiffer depending on your personal preference.
Chassis Bracing
Chassis flex is the next thing you’ll want to take care of after ride height and body roll. The little flexing between your strut towers or with your subframe can really compromise the feel of your car.
034 Motorsport Strut Tower Brace – 034-603-0012
One of the first chassis braces to consider is a Strut Tower Brace. The reasoning behind this is that when you are cornering there is a considerable amount of flex in the frame which leads to a disconnected feeling at the steering wheel. The 034 front strut brace not only offers superior strut tower to firewall bracing, it also includes a crossbar connection between the two braces so you get a physical connection between the two strut towers so you’re reducing lateral and longitudinal flex.
034 Motorsport Rear Subframe Inserts – 034-601-0046
The next chassis bracing you should consider is some Rear Subframe Inserts from 034. These little billet aluminum pieces work wonders for sorting out the rear suspension. They are basically little billet pieces that fill the gaps in the rubber subframe mounts so you have a more predictable and connected feel to your rear suspension. They are also a great addition to a rear sway bar as they allow you to feel the effects of the sway bar more clearly.
Suspension…(Current)
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Intake:
An intake is one of the easiest ways to get extra power out of your car. The reason you would install an aftermarket intake on your car is that most factory intake systems are very restrictive and often have a resonator attached to muffle the sound of the intake. Therefore the benefit is twofold, an intake will make your engine sound a lot more aggressive when you’re driving and you get some extra power out of it due to the increased flow.
Available Now
Injen – SP3087 (2.0T A4 Only)
Injen is the absolute go to company for aftermarket intakes. They put so much engineering and testing into every intake they design that you can always count on them to provide a quality product. Their A4 2.0T intake is no exception. Their super nano-web filter technology and dyno tested intake tubes ensure maximum airflow and gives the A4 an extra 14 hp and 12 ft. lbs of torque on average. Multiple color option also give you the option of customizing your engine bay to your liking. If you own an S4 then you’ll have to wait a while until they finish development of their intake for the 3.0T.
Coming soon
AWE and Eventuri
AWE currently has intakes for both the A4 and the S4 in development. AWE intakes are historically very well built and give good power gains so if you aren’t a fan of the Injen intake (or own an S4) then the AWE intakes will definitely be worth waiting for. If you’re looking for a very high end show quality intake then keep an eye on Eventuri. Their intakes are expensive but they are some of the most high quality and visually appealing on the market.
Intake…(Current)
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Exhaust:
In a lot of ways an aftermarket exhaust is the trademark of a modified car. Wheels are of course on of the biggest visual indicators but an exhaust is what makes you look up from whatever you’re doing so you can see what car is driving by. Furthermore you get more than a louder exhaust note, aftermarket cat-backs (and some axle-backs) can net you a decent amount of horsepower and torque, along with visually improving the back of your car.
Available Now
AWE Exhaust for A4/S4
AWE is a great option for anyone who loves having tons of options. AWE makes three main versions of their exhaust: SwitchPath, Touring, and Track. The Track edition is their bare-bones no nonsense version. It features no resonators and no mufflers, you just get two pipes straight out the back which makes it the loudest of the three choices. Touring is the next tier exhaust and it has two resonators and two mufflers. This makes for a much quieter and more refined sound than the Track Edition for those who like attention but not too much. The SwitchPath is the top tier AWE exhaust for good reason. It combines features of both the Track and Touring and gives you the ability to switch between them with a remote controlled valve. In open valve mode it is about as loud as the Track Edition and with the valve closed it is in-between the Track and Touring in terms of volume. For every edition you also get the choice of four different exhaust tips styles (two colors and two sizes) so you can really go to town customizing this exhaust. The A4 has the same options of Switchback, Touring, and Track editions and the same variety of exhaust tips. Below are sound clips from each of the three editions for the B9 S4 so you can hear the differences between them all.
Milltek Exhaust for A4/S4
The Milltek Exhaust may not have the SwitchPath option of the AWE but they make up for it with excellent build quality and exhaust tone. For the S4 exhaust you get a choice between resonated and non-resonated versions as well as versions for vehicles equipped with the sport diff or the standard diff. Their A4 exhaust has options for resonated, half-resonated, and non-resonated. For exhaust tips each version gets about 5 choices in different colors, shapes, and finishes. You can check out the video below to hear what this exhaust sounds like on the S4.
Coming Soon
Remus Exhaust for A4/S4
Remus is a staple in the Euro market so without a doubt they will be developing an exhaust for both the A4 and the S4. From Remus you can expect a great deal of research has gone into their development process so when their A4/S4 exhaust is released it will be among the best in terms of power gains and build quality. Check out the B8 S4 Remus Exhaust to give you an idea of their usual power gains and options.
Exhaust…(Current)
[nextpage title=”Exterior”]
Exterior:
If you’re looking to really stand out then the best way to make your A4/S4 really unique is with some exterior mods. There aren’t that many parts available at the moment but there are always new pieces in development because of their popularity. You will soon be seeing a wide variety of front lips, splitters, side skirts, rear diffusers, wings, etc.
Front Grille
B9 RS4 Style Mesh Grilles – GR-AUA4B90-RSxx
If you’re not a big fan of the horizontal bars on the stock A4/S4 grille then consider one of our RS4 Style Mesh Grilles. These grilles feature a more aggressive honeycomb design reminiscent of the top tier RS4 models. They come in a gloss black finish in either a standard full honeycomb or with a “Quattro” badging in the bottom section. This grille is a quick and simple way of subtly improving the look of your A4/S4 front end.
Body Kits
Morph Auto Design – Coming Soon
Morph Auto Design is a favorite for us because they are the first company to make modular body kits. What this means is that instead of buying a whole new lip or diffuser to change your look, you can just get a different attachment and completely change the look of your car. Morph has already reached out to the B9 community for feedback on their design concepts and are in the final stages of making their full B9 kit. Below you can see how the modular system works on the existing BMW M4 diffuser, as well as the concept photos of the B9 kit (production photos will be added when available).
Morph Auto Design Modular Rear Diffuser
If you have any questions about mods for your A4/S4 that aren’t answered here or just want more details our Mod Experts are always ready to share their expertise and experience. Contact us at: sales@modbargains.com or call 714-582-3330.
Exterior…(Current)