It is hard to argue out of the box handling performance on a B7 S4 (or any Audi Quattro for that matter), even with All-Season Nokian tires, factory suspension that is 11 years old, and no other real upgrades or modifications, she sticks. However, when we were last with Project B7 S4, upgrading her brake components with units from Zimmerman and Akebono, we noticed that our factory OE red shocks were showing some serious age and could do good being replaced. One sign of this I noticed while the vehicle was down on the ground, was the stance. Awkwardly, our project vehicle was sitting lower than most similar models I have seen. About an inch off the tire, though appealing, did not jive well with me. This is usually a good sign that you may have a blown shock.
Enter Bilstein, and their B8 Performance Plus shock replacements. As aforementioned, project B7 S4 does not belong to us, so we can't get too crazy with things we can do to it, however, that does not mean we can't keep a factory stance while still considerably enhancing the ride quality and overall handling performance. Along with these Bilstein units, we got some goodies from our friends at 034 Motorsport, who have recently stopped by and toured our facility and expressed interest in helping out with our project. They were kind enough to provide us their HD front strut mounts to compliment the Bilstein shocks.
Some benefits of running the Bilstein B8 package I have also put together for Audi B7 S4’s: - Monotube gas pressure construction - High-performance shock absorbers and struts designed specifically for lowering springs and production sport vehicles - Sport-tuned with a high level of comfort - Precision handling and optimized vehicle control - Road-tested and fine-tuned by Bilstein Originally intended to be paired with lowering springs (which may not be out of the question for project B7 later in life), these shocks are still fully capable of supporting Project B7 S4 with the factory springs and will provide exceptional ride quality. Audis of this vintage, and for a span of almost 20 years, have featured a multi-link front suspension where there are four control arms supporting the front spindles. Each upper front arm bolts to a hat that supports the shock from up front, and bolts to the lower arm in turn linking it to the bottom of the spindle. The reason for this is the engine sits up front, as does the steering rack, and Audi more frequently offers these models in FWD trim, requiring a more durable and efficient front multi-link. In disassembling our front suspension, we first begin by unbolting the front upper arms from the spindle as well as the tie rod. These spindles are aluminum and are known for their frailty, I highly recommend for anyone pursuing a similar repair to first soak these in PB Blaster in order to aid in their removal. Once they were removed and the hat unbolted from the strut tower, we removed the lower shock bolt and slid the assembly out of the wheel well, and mounted it in our vise. In doing so we spotted another problem lurking with Project B7 S4.
Now, when we first took the car out for our initial review, I noticed a popping sound going over obstructions in the road that did not sound like an issue with the shock or with a lower ball joint. It turns out that with the shock removed and set on our workbench, we could see our upper control arm bushings were completely shot, allowing for them to turn in the locating bolt in the housing. This turned out to be the source of our noise and is a common problem on these multi-links. As we weren't going to overlook a faulty part while replacing another, we took to opportunity to replace the arms while we serviced the shocks with replacement units from TRW, an OE manufacturer for Audi suspension components and a suitable match to the Bilsteins we were looking to install. Another complementing addition to this repair was the installation of the 034 Motorsport HD strut mounts. I would recommend to anyone working on a project like this never replace the shocks without also tackling the strut mounts. 034 Motorsport came through in the clutch by providing us with their HD units that are far more durable and best suited for an aftermarket shock like the Bilstein units.
Upon reassembly of the new shock, HD mount, and aluminum hat using the new OE TRW arms, we went ahead and brought the trio into place under our B7’s wheel well. The process of which was fairly tedious to do but none of which impossible for one person to tackle over a weekend. Installation of the rear shock was all too easy, as the rear is a coil off shock design. It was as simple as bolting the rear shock mount and lower shock bolt and installing the new unit from Bilstein.
Upon completion of the installation, we took Project B7 out for a spin, first to test our work and second for me to get impressions on the new hardware. The difference was night and day, handling was exceptional, turn in was sharper and crisper, ride quality was less floaty and more refined. I took my sweet time enjoying the new feel of our S4, and I have to be honest, the car felt completely different. While this package does not include springs, our package can be had for a fraction of the cost of a complete coilover setup, all while still giving the end user the capability of using lowering springs in the future.
Mike is a former ASE Certified Technician and has over 10 years experience working on various European makes and models. This FCP veteran has been with us for almost 8 years and has worked very closely with our customers helping with technical advise and service. Mike is our Audi & VW catalog manager and is heading up the build out and restructuring the Audi & VW segments of the FCP Catalog. He can be reached at firstname.lastname@example.org