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.
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 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 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.
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 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.
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.
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.
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 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.
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.
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.