B5 RS4 Bilstein PSS9 Review

[don]

I have now had PSS9s installed for about two weeks, though some of my impressions are based on a drive immediately after install so I will update again later once the springs have fully settled and I have lowered the car to the correct height.

Prior Set up
I previously installed the H&R fat antiroll bar with both front and rear bars set to maximum stiffness, did not affect ride quality. The bars a lone made a significant difference, particularly at low speeds and turn in, but was still very floaty at high speeds and unsettled in corners and undulations.

I was concerned that the ride quality with the PSS9s would become significantly harsher but I don't notice any great difference in the compliance between the PSS9s and the standard. Roads are also very bumpy over here with pot holes, old concrete slab types and old bitumen.

My original suspension had done approx. 20 000 miles so was still much like new.

Spring height and firmness
The PSS9 progressive rate springs are certainly firmer. I am no fatty but pushing down on the fenders there is little give whereas before there was considerably more.

The mechanic set the ride height to maximum until the springs settle and it was about 1 cm higher on install.

After two weeks it looks like it is probably sitting a tad higher though the measurements now seem very close to stock @ ~ 66 cm rear & 65 cm front. Ride quality still feels the same.

I will probably lower the car by about 2-3 cm when I get around to it and on spirited drives maybe more, but I look forward to the experimentation.

Damper Settings
The Bilstein monotube dampers are gas pressurized types with 9 combined compression and rebound settings. The manual states 1 is firm and 9 is soft.

I had them set to 4 which is about mid way.

Turning the front wheels on full lock the adjuster knob is easily accessible and visible. For the back wheels you have to lie down and reach under the back of the car over the rear wish bone. The dial is then easily accessible by hand but not visible. Car ramps would probably be handy for this part.

Compared to the KW V3s I have heard that the Bilsteins are more responsive but as a result can be a little skittish and provide less give in the first few mm. I believe the extra responsiveness is due to the high gas pressurized system, valving and piston size in the Bilsteins. It seems to be down to personal preference whether one wants their dampers to be more or less responsive.

The KW V3s also have independent and greater rebound and compression adjustability but the rear shocks must be removed to adjust.

I liked the idea of being able to easily adjust the Bilsteins to a firmer setting in a matter of minutes for spirited drive days.

Impressions
Immediately after install I went for a spirited drive through a number of sign posted 35 km/hr to 45 km/hr twisties on a variety of smooth to rough road surfaces. Car was a little high but handling was definitely better.

I took the Misses who is usually having kittens during drives but she also felt the car was much more stable and safer and no complaints were heard which is unusual.

Despite the springs having not settled in, body roll was noticeably improved and car feels much more balanced through turns. Turning in felt much more neutral and directed. I notice a slight roll and change of weight and then the springs appear to firm up nicely.

The car is now much better damped and no longer feels unsafe or out of control. Is much less bouncy but no real noticeable loss of ride quality.

I will probably set the dampers firmer to the number 3 setting as I still believe the car is a little under damped. Though I will lower the car first by about 1 inch to see what difference that makes.

I am yet to test the car on any high speed cornering but I expect the firmer springs and stronger damping will help.

Conclusions and comparisons
Obviously Bilsteins are a very reputable brand and they perform very well with easy adjustability. There is also no noticeable loss in ride quality/comfort and if necessary the ride height can be set as stock or slightly higher.

Competitors include KW Variant 3s and Stasis Track Sport and all are within a similar price range with KW followed by Stasis being slightly more expensive. Both the Bilsteins and KW V3s have rebound and compression adjustability, though the KWs has independent rebound and compression. The Stasis is rebound only but comes with a 90 day spring exchange program, Koni adj shocks are used with Stasis digressive valving.

Bilstein is gas pressurized and is said to be more responsive than KW.

Bilstein has a digressive piston head design and deflective valving, whereas Stasis talks about digressive valving.

KW make an RS4 specific set up where as Stasis and Bilstein use the same setup for the S4.

My main reason for gong with Bilstein over KW was the ease of damper adjustability. I would have gone with Stasis but my driving style did not justify the added expense that I was quoted.

[Jarv]

Excellent write-up don, look forward to more feedback once you've lowered the ride and lived with it for a bit. I'm toying with the idea of replacing my standard setup, and defo leaning towards the PSS9's.

[Virdee Autos]

Thanks for the top write-up/impressions.

Look forward to your final views.

I'm also leaning towards the PSS9's at the moment. And after hearing there is no detrimental effect to the ride quality, it sounds even more enticing!

Edited to say, did you just put the kit on how it was setup out of the box, or is it still the case where you have to build up the kit?

Either way have you gone for the recommended settings in the manual or your own?

[grizz]

The pss9's work very well on the rs6 as well , they are simple to fit and set up . As for setting up get the ride height set & then set them on 4 or 5 , this is the mid setting and TBH I've found it works well .

[ZeroK66]

Fantastic... having mine fitted as we speak, MRC have my car and I am having the complete front arms/bushes etc replaced, so I expect the car will be great, I cannot wait.

Doug described taking a corner at 40MPH LESS in my car than what he did in his regularly and my car felt unstable... needless to say my old H&R coilovers were totally knackered.

What have you got your ARB's set to now? Mine are both currently on maximum stiffness... not sure if I should be softening the front to help with turn in?

[don]

I've changed springs and shocks before in my old E30 BM but this time I didn't do the install. However, I don't think the PSS9 install would be difficult.

To remove the OEM kit renting a good set of spring compressors would be essential particularly for the rear. The Bilstein struts will then go straight in and simply a matter of loosening off the rear before install.

I didn't notice any recommended settings in the manual though most mechanics/people seem to recommend setting the dampers to somewhere midway, 4 or 5. Though easy to adjust later on if need.

My mechanic set the spring height to maximum which has now settled to approx standard height. Personally, I would have started with at least 10 cm lower. I suggest before install you adjust the spring sleeves down from max height to your desired height from standard unless you are worried about not getting back into your drive way.

My ARB settings are both on maximum and turn in is better again with the Bisteins.

You might want to set the front ARB to middle or min setting to further reduce understeer/increase oversteer but I think the car is perfectly balanced with both bars set on maximum. I think this is more personal preference depending on how much you like to get your car to drift.

Look forward to hearing how you all go and what people find are the best settings.

[zeke]

Don,

Nice to know you still have your RS4, I just bought my coil over from stasis (after 50,000 kms. of the original susp.) B5 MS Suspension with 700 lbs springs on front and 900 lbs on the rear, they work excellent in the track and you can adjust the bound and rebound pretty easy too, with around 30 clicks.

http://www.stasisengineering.com/Catego ... =50&PID=88

The best height for the suspension to work for the B5, is to measure from the middle of the wheel to the beginning of the fender to be 13 inches and because in our suspension you can’t adjust the front camber, at this high the caster will go to 1.75 negative in the front and at the rear you can adjust it to around 1.50 negative camber. Stasis says you have to adjust it between 13 and 13.5 inches for the suspension to work well.


Saludos

[don]

Zeke, this is very useful information.

At the 13 inch mark that gives me about 2 cm below standard or the current max height set on the Bilsteins which I expect will work very nicely at that height.