Long!
possibly incoherent rambling...
Several months ago, I had Stasis': Ohlins coilovers and Alcon 370mm BBK installed. Now that I have had a chance to track the setup as well as run it a bit on the street, I thought I'd share a review of their performance effects/characteristics on street and track versus the stock sport suspension and brakes. If you are interested, read on...
The suspension and brakes were installed in my 2009 A4 Avant S-Line. Current performance mods from Stasis' lineup include the ECU tune, exhaust. I have enjoyed tracking this Avant for the past couple of years. Unfortunately, each track event left me with brake issues from bothersome boiled brake fluid to more serious, master cylinder failure, not to mention heat cracked stock rotors front and rear... the list goes on. NikZag and I communicated about our similar braking issue for some time. While we were both looking for solutions that would solve our problems while using the stock brakes, I think we both agree that we push our A4's harder than most and that to err on the side of “bigger being better” could never hurt.
For brakes, I considered the Brembo, StopTech, and Stasis' Alcon setup. I initially balked at the Alcons since the smallest setup uses 370mm discs and I had 2 sets of 18” wheels as well as the heavy OE 19” “peelers”. I have used Brembo in the past and have a set on another car in the garage so I began leaning in that direction. I liked the idea of lightweight stealthy silver calipers so I started looking at the higher end offerings. The Brembo GTR's are quite pricey to justify installing on an A4 so I looked at StopTech's Trophy brakes which were more affordable. After a lot of comparing, I came to the conclusion that the Stasis/Alcon 370mm BBK was the route I wanted to go because it would offer everything the GTR and Trophy sets would and also have the benefit of dealership support/service. There was one downside to the Stasis 370mm BBK. Both of my 18” wheels wouldn't clear the caliper by more than 1-2mm so I had to go back on the original 19” peelers while I hunted for a new wheel.
The outcome of which was documented here.
I wouldn't say that there was anything wrong with the factory sport suspension. It was a pretty good compromise. With progressive spring rates, the factory sport suspension took a moment to take a set when cornering. When cornering, there was a moment of delay followed by body lean as the initial portion of the progressive springs compressed before engaging the stiffer part of the coil. Once the stiffer portion of the springs were in play, the cornering performance was consistent. It was safe and predictable with predictable understeer (mitigated somewhat by a Stasis ARB) at the limit. It of course lacked the edge and adjustability that I wanted but overall cornering grip was good for a relatively stock car. I had held off from ordering the Ohlins Challenge coilovers when we bought the car because I was hoping that Stasis would develop the Ohlins Motorsports setup with the remote reservoirs. The planets failed to align properly and that never happened so the Ohlins Challenge setup went in instead.
The install process was as straightforward as it has been for the rest of my Stasis mods. I dropped it off at Pacific Audi and they set me up in a nice loaner (new Q7 with Supercharged V6) for the few days that the install would take. When I picked up the Avant after the install, my initial impression was that
she looked too low and would probably scrape on speed bumps. I was sure that I would end up raising it a bit. Left the dealership and had no problem entering the street. With that first turn, I noticed something unexpected. With over 10+lbs/front corner shaved, turn-in was improved and steering effort reduced. I was gentle with the brakes until they were bedded (more on that later) but I noticed an immediately firmer pedal.
I was able to bed them the day before we left for Nationals. They have performed great on street and track. What is “great”? What does that mean?...
According to data from my Traqmate, that means that on-track the Alcons were consistently delivering 0.995-g from 1st to last lap every session and I'm sure there was more braking available. I don't have data from the stock setup but according to Stasis' website, they are showing 0.91-g for the stock brakes. That doesn't seem bad for stock brakes, except that they aren't able to perform that way lap after lap. After 3 hot laps of most tracks, the factory brakes start to progressively fade to the point that engaging ABS is impossible, when everything is working as it should.
When it's not working as it should, the factory brakes provide a range of opportunities to practice your “pucker” as you watch your normal braking zone fly by at a seemingly faster pace than expected... Entering the braking zone of T2 at Laguna Seca at 125 mph only to find that your brake pedal, like the accelerator, is willing to go all the way to the carpet... Well, let's just say that you've been lied to...moments like that, do not grow hair on your chest... Entering the braking zone for T14 at Thunderhill while traveling 120mph is great fun until you press the brake pedal and feel the pedal slowly drop to the floor as your master cylinder quits. I wasn't so worried about me or the car but I was wondering how I was going to avoid the photographer in the grass ahead of me. ...Personally, I think there were some guardian angels, track fairies, or something out that day. The real bitch about blowing the line/saving the car/photog at that corner is that it put me out of line to make the pits, forcing another lap with no MC granted that at least that lap I was aware of the issue and was able to baby it back. Still, not something I wish to repeat...
Back to the suspension... How does the Stasis/Ohlins Challenge coilover setup compare to the stock sport suspension? The ride is smoother than the sport suspension and yet when the road gets windy, the suspension is always able to keep pace with immediate response. Mullholland and the surrounding canyons are filled with off-camber turns filled with dips/bumps. Cars that are lowered excessively will very quickly find their lack of suspension travel interfering with fast forward progress. No problems here. In fact, my concerns about speed bumps was unnecessary. I actually ended up going a bit lower when I took the Avant in to have her corner balanced.
I made these composites (not sure which is easier to see) to give an idea of the difference in the Avant's composure before and after the suspension upgrade.
This shows the attitude of the OEM sport suspension in outline versus the attitude of the car (solid image) after installation of the Ohlins coilovers.
and here it is reversed so that the outline is the improvement and the solid image is the before photo.
They are merely representative of the difference in cornering attitude pre/post Ohlins coilovers.
My suspension specs currently are as follows:
Front Left Right
Camber: -2.0' -2.0'
Caster: 8.75' 8.7'
Toe in: 0.10”
Rear Left Right
Camber: -1.4' -1.4'
Toe in: 0.12”
I didn't measure the car prior to the installation of the Ohlins coilovers but after lowering it a second time while corner balancing, it now sits as follows:
Fender Heights (with driver)
Left Front: 25 13/16” Right Front: 25 15/16”
Left Rear: 25 15/16” Right Rear: 26 1/16”
Weight distribution:
Left Front: 1102 Right Front: 1031
Left Rear: 986 Right Rear: 908
Front weight: 2133 (52.9%)
Rear weight: 1894 (47.1%)
At Audi Club Nationals, I did some data logging with a Traqmate. I can't say how the cornering grip changed since I hadn't run the Traqmate before the swap. It recorded 1.58 g's max right load and 1.2 g's max left load. These are not skidpad numbers. The 1.58g max right load occurs at the apex of T3. Turn 3 at Infineon is a sharp uphill left leading to a blind right. Still, an Avant at 1.58g on street tires, even with the benefit of the uphill compression is impressive, imo.
As I mentioned before, I didn't have the Traqmate before the suspension/brake upgrade but I can say that the change in lap times is DRAMATIC! On the stock sport suspension/brakes/wheels, my best lap at Infineon was 2:13.849. I ran a best 2:10.451 lap post STaSIS suspension and brake upgrades!...not too shabby for a 3857 lb. wagon with a four banger. Both of those times were set on the same 19” peelers shod with 255/35/19 Continental ContiSportContact 3's. I bet that the Stasis center diff would cut times even more unfortunately it's for MT's only and so us Avant owners here in the States miss out on that.
This 2.0 Avant has become a stock B8 S4's worst nightmare thanks to STaSIS. The most noticeable difference being that where a stock B8 S4 is hard on the brakes, I'm still full throttle for the next 50 -100' before I need to consider braking and that just becomes amplified as the laps pile on.
FWIW, I discovered that the carpeting in the B8 Avant does NOT hold velcro. But the carpet on the Avant rear tray does. Just in case you are ever trying to affix something to the floor...
I know this is really long but I sincerely hope it helps someone without boring you to death. Please excuse any disorganization or rambling as I'm on post-op meds. I think I covered everything. Feel free to shoot me questions.
I'm looking forward to Laguna Seca in a few weeks as I haven't had a chance to run LS since prior to the brake and suspension upgrades. The Andretti hairpin is always a great brake test after coming down the straight. I'm sure I'll be
not 
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Neuspeed exhaust, Eurocode bits
Originally Posted by Info@EuroCode
Those composites were a PITA for me since my Photoshop skills are pretty close to non-existent as Blake was so apt to note in the "random Pic" thread. I'm a very 'visual' person, so the composites really helped me see how much of a change had taken place. Data is all well and good but seeing the outcome is priceless.
) It's nice to know that it might actually be useful/helpful.
I most likely would have saved money by upgrading to the Alcon 370mm Mono 6 sooner. This is not my first BBK so I was prepared for the costs. For me, the benefit of safe,consistent, and repeatable deceleration at the track or during canyon runs is well worth the price of admission. 
Damn alarm, gotta run
Well said.
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