I got that CR-15 bar from AZ for $130 + shipping IIRC
Didn’t think it would help much, but decided to try, since it’s fairly inexpensive
Was surprised with the results. It’s not night and day of course, but it definitely brings more improvement than Alu Kreuz.
AK from EuroCode is a joke for the money it costs, but I’m a cheapskate so I picked up a used one (because what seriously could possibly happen to a chunk of aluminum?). For the price of the used one it’s okay-ish
After 25k miles my spherical bearings need replacement. I also need a new right side lower control arm because the boot on the end is torn and it’s not replaceable. I’m going to do spherical inserts in the upper control arms as well while the suspension is being pulled apart.
The guys at the shop were shocked the parts lasted that long.
WTF the LCA needs replacement due to a torn boot? Which boot are you referring to? The ball joint?
You are scaring me with the LCA news 
I am also shocked your spherical bearing lasted a whopping 25k miles (without developing play till recently??).
The UCA bearings will help dramatically. Or you can get the whiteline offset bushings. Firmer than stock and up to -.75 more camber adjustment.
Oh I thought I should update this thread, since the topic is “suspension”.
I recently switched to RS5 springs and shocks. They work well on the S4. Ride height is reduced, and despite the RS5 having a big v8 on the nose, the springs are actually shorter than stock, and the engine weight difference isn’t enough to raise the front end or anything. So the car doesn’t look funny either.
A quick blurb from my musings on the blog on this topic: The ride quality of the car has firmed up dramatically - this is much firmer than when it was stock. Firmness is similar to an E92 M3 without EDC. Steering response has improved. And for the short period that I did drive the new setup on summer tires, the turn in was sharper. The car now has a new found level of adjustability that it never had when stock. On the street, it also feels more adjustable than the kw’s. Going hard on offramps, the back end will rotate ever so slightly as the brakes are lightly brushed, while keeping a poised balance and stability. The body motions are more controlled and slower, yielding a much finer level of adjustability that it did not have previously. Hitting left turns harder while trail braking into them also yields minor rotation on the street. Release the brakes slowly, and the front end bites as the car turns in. Roll into the throttle and the sports differential steers that rear end even more for more rotation. Be more judicious with the gas and be ready to counter steer on the street!
'course, the RS5 has a V8 up front, so naturally the front springs will be firmer than the OE S4 springs by quite a margin–lets also remember that the entire engine is slung ahead of the front axle. Naturally, you are going to need more spring and shock to control this. In the end, this is actually what I was looking for, as the increased bump stiffness will improve the car’s turn in. The firmed up RS5 springs and shocks coupled with a front bar set to max stiff however makes the front end break loose before the rears–if I try to be abrupt and force this to happen. Note though that this is on winter tires, so the suspension will not be loaded up as much and the limits are lower. Behaviour may differ on summers. Readers note: I still have my sways set to full stiff all around. If more trailing throttle rotation is desired, loosening up the front bar will fix that. More on this after a shakedown run at Mosport. From what I can tell on the street though, the balance is there and the car can be made to rotate with little effort. It does not behave like a stock s4 in any way. Totally different animal. Ultimately, having the front tires break loose before the rears make for a confidence inspiring drive. This coupled with the level of fine adjustability the car now has gives it a very entertaining character. Making the S4 go sideways on this setup is no problem.
Pix below. FTG is 26.5 f 26.25 r. It isn’t reverse rake as we all know, the rear fender height is lower than the front.
http://i65.tinypic.com/x5dulu.jpg
I am pretty certain it’s this rip on the right side of the photo, from April 2014. Hasn’t been an issue since I garage the car, don’t drive it often, and it hasn’t rained in California in years. It’s best we address it now because eventually water will get in there. The new control arm is $400 Audi OEM or $200 aftermarket - aftermarket is ok because we just need the cast and are replacing the other bushings with sphericals anyway.
Two of the bearings need to be replaced at a parts cost of $45. Unfortunately the total job will be over $1k.
Great write up. I think this is a better option than the low end coilover kits. You might want to experiment with a slightly stiffer rear spring, as long as you don’t mind trading off some rear passenger comfort for performance. I do believe the front bars set to stiff is the right setup for having safe fun in this car. It’s very easy to correct high speed corner entry mistakes by just opening the wheel - no BMW tank slapper fails and off track excursions. As I mentioned previously I’m running a 600 rear spring so my rear bar is set to soft. I think the torque vectoring technology works better with no rear sway.
http://images.tapatalk-cdn.com/15/12/30/247708405d8486c7eff48c3d60f65fd2.jpg
http://images.tapatalk-cdn.com/15/12/30/16b3498265a5f7670f3d5ef8faa15ebb.jpg
This is the old bearing that was replaced. Check out the scoring. There is what feels like a small amount of play to me, but there is a lot of play according to the mechanics.
http://images.tapatalk-cdn.com/16/01/07/d005539828dc3be9f9ff0387188212e3.jpg
http://images.tapatalk-cdn.com/16/01/07/135c0aa3d0e0e86c9a5fb0c9b21128b9.jpg
http://images.tapatalk-cdn.com/16/01/07/9160c12153ebff378db5b7c31d5a2492.jpg
http://images.tapatalk-cdn.com/16/01/07/22d555452d5b13c35473029509479d5c.jpg
http://images.tapatalk-cdn.com/16/01/07/0ccb42e1f168534a1a19c928b09e1291.jpg
http://images.tapatalk-cdn.com/16/01/07/3b5fe880fe3f8651bad25588c67fe394.jpg
http://images.tapatalk-cdn.com/16/01/07/9feb7dcf11d4f03081add3b9a3e70f9b.jpg
http://images.tapatalk-cdn.com/16/01/07/9b6daf0b29bd5eb31d45fb5816c283b9.jpg
http://images.tapatalk-cdn.com/16/01/07/025fb1bb8084efa1676fc2e9e892bcbe.jpg
http://images.tapatalk-cdn.com/16/01/07/a0c15c6ace1a6d4c465df9ad915c61da.jpg
http://images.tapatalk-cdn.com/16/01/07/5122bb0d152cd84eb10fc52194d830c4.jpg
http://images.tapatalk-cdn.com/16/01/07/caf7cc8beba142d600765612512623df.jpg
http://images.tapatalk-cdn.com/16/01/07/441747f21da8ebbd1e0b5a8c026fa8b8.jpg
http://images.tapatalk-cdn.com/16/01/07/9a67c228b3157fe34cf2ee7c4d21a820.jpg
Very cool.
Just wondering, what were you trying to show in the picture of the sports rear diff? Looks too low to see the bushing inserts.
West - which upper arms are those, and are they near or at max camber? If so, what are the camber #'s?
For SPC, when I was about 25.75 FTG, I was -3.0 camber. Topped out. Now at 26.5FTG, it’s topped out at about -2.6. I’m hunting for arms with more adjustment range if they exist.
We’re trying for -3.1 camber today. Will report back.
Shared a picture of the pumpkin just because I thought it was cool. The only real change in those photos is the new control arm with the blue tape/sealant around the boot. And the sphericals in the 034 Upper Arms. Man it rides firm.
Will you re-list what you have done at this point?
Regarding the suspension, this is my set up:
- eurocode swaybars
- firm 2/2 setting front
- soft 1/2 setting rear
- eurocode endlinks
- JRZ RS1 one-way (rebound+compression) coilovers
- softest click 1/24 front
- soft click 4/24 rear
- 500 pound front spring (8" with helper spring)
- 650 pound rear spring (8" with helper spring)
- 034 upper control arms with spherical bearings (4 bearings in total)
- 034 aurora bearings in lower control arms (6 bearings in total)
- eurocode drivetrain stabilizer
- AZ dude firewall tower brace
Will post an alignment sheet tomorrow night.
West, what are your tire temps like?
I would think you don’t need -3 degrees on a double wishbone car that has no more rubber bushes.
I ran -3 because of the compliance, and my temps were in check with rubber bushes. You can probably get away with something like -2 at this point–and get more grip under braking.
Just curious how your temps look?
Thanks for posts (both West and Boro). Good info for us to have. I thought the text would help with the pics, and at least for me, makes a lot more sense.
Point taken. I consider -3 to be an OK range for a dedicated track car. I consider -4 to be extreme. I’m not worried about tire wear as I have a predictable 12 month 3500 mile replacement cycle. I have started rotating at your suggestion.
Tire temps are pretty even across the range as long as I’m not purposefully trying to destroy tires for laughs. Like 150 / 155 / 150. Obviously it varies by which course and by which turn I’m working on mastering that day (a left hander or right hander).
150/155/150. Interesting. What were your camber #'s again?
I see a similar spread on my setup – but I do not have sphericals and I ran -3. I would expect to see a better spread on your car with solid bearings all around. Either that or you may not be trail braking as often as I am. If one gets on the power before the apex, you’re going to put more heat on the outside edge of the tire.
Toe is 1/16 each side so 1/8 total. Last time I had 1/32 each side, 1/16 total.
http://images.tapatalk-cdn.com/16/01/08/b9a752f2b4b48197af3ddc6ce2d45ed8.jpg
With driver and half tank
http://images.tapatalk-cdn.com/16/01/08/e19f02acd1415fee55885241dab7f263.jpg
Here is last year’s sheet (12/2014) for reference
http://images.tapatalk-cdn.com/16/01/08/3acd191844e6c1cd9430c919934a2bbb.jpg
Interesting numbers!
I would have thought you would run more rear toe with the spring rate you’ve got on the car.
Did you re-do the corner balance after the seats? Looks like your old toe #s were all out of whack. I suspect bc the corner heights were changed if you re-did the balancing.
Regarding the tire temps, I’m told it’s okay or even desirable to run the inside of the tire a bit hot. On the right side of the car (in a track with mostly left turns) I’m seeing even temps about 135F ±4. The outside is getting used a lot. On the left tire I’m seeing 140F inside, 135+ middle, 120 outside.