[Scott-AhlmanPerformance]

Thanks for the input everyone. Sounds like the BIlsteins are comparable to the Ohlins, which is what it had seemed to me, from what I could find. I had forgotten about KW, but that's another one that seems to be an upper tier. Good stuff.

I can tell you the stock Bilstein dampers (un-adjustable) on a 2017 RWS are tuned well for the base spring rates (Driving it on the road and running some mountain twisties). I have not tried these or looked at the curves and spring rates, but there are some notable differences to our Ohlins TTX's and the description for these in your original post has a noticeable contradiction. The picture for the ones you included show remote/external reservoirs. But the description says, "The 2-way adjustable suspension system, complete with an integrated reservoir, provides a significant weight advantage for racing and clubsport use compared to systems with external reservoirs with what I assume is compression adjustment on the reservoir and rebound on the shaft. Do your Bilsteins look like what is pictured?

 

[Scott-AhlmanPerformance]

Hi @torqueit, Understood. I have reviewed the TUV/Manual you posted. It is great you like them as the overall Audi R8 chassis is such a good foundation.

The Bilstein manual doesn't seem to show spring part numbers (Eibach's) that tell us the rates. One of the front pictures may show the front rate of 120 N/mm, but not positive - this seems low for the ride height range. I am surprised these were TUV approved without specific damper adjuster settings specified, though the compression adjuster on the remote reservoir doesn't change the behavior to any significant degree and not sure on the rebound adjuster actual curve adjustment. @torqueit have you tried adjusting these Bilstein Clubsport damper adjusters?


Quality/Reliability - Öhlins TTX and Bilstein Clubsports are Similar
Bilstein's Clubsport quality/reliability I would say is on par with Öhlins TTX's based on reputation and lack of knowledge of otherwise.

I believe Bilstein uses a dry shaft seal for these Clubsports like Öhlins does (for durability and eliminating constant service) while maintaining low friction. Many "racing" dampers use wet shaft seals intended to reduce friction, but they lose a little fluid with every stroke. This is not an issue in racing due to constant valving changes/rebuilds. But the wet seal requires rebuilds every season for passenger cars that are driven a few thousand miles plus.


The following highlights some significant differences for others to consider when looking at suspension options.


Advantages for Öhlins TTX's and Ahlman Performance

Settings/Setup Specified by Öhlins and Ahlman Performance
Whether the Öhlins developed TTX Pro Advanced Trackday (smooth road track biased) or our Ahlman Performance developed Stage II (balance of road and track - from smooth to rough roads and tracks) the adjuster settings are specified for the road (more toward ride) and the track - biased toward handling and response. We focus on connecting our customer's better to their cars (and engaged more in the experience) with more direct/linear steering response and feel, more grip with more consistent balance throughout the corner and improved ride and control. The R8's reponse becomes more engaging and predictable.

A lot of analysis and development time and effort has been put into getting these right to provide safe performance for our customers. We do not believe this complicated process should be left to the customer to tune on the street or otherwise.


Adjustability
The Öhlins TTX's for the R8 are two-way adjustable, like the Bilsteins, but the Öhlins have 20 clicks for the low speed compression and 20 clicks for the low speed rebound adjustment. The Bilstein list 10 clicks for each, where-as noted their compression adjuster range is very limited due to acting on the remote reservoir. This limited range is due to the only fluid going to the canister is from the rod displacement and not the piston.

The Öhlins TTX adjusters have the entire fluid volume going through them 100% of the time due to a different design with a solid piston and the valving and orifices all at the adjusters.

This means the Öhlins TTX adjustments can actually be felt and change the car in 1-2 click adjustments

The Öhlins TTX design can also readily be changed to 4-way adjusters at any time

The Öhlins TTX adjusters for the R8 can easily be seen and accessed at the tire fender opening with the wheel/tire at full rebound (the car jacked up and used of short jack stands for safety.

It appears the Bilstein Clubsport compression adjuster is through a small access hole in the fender liner and it is unclear if one can reach the rebound adjuster at the top mount without fender liner removal or modification, but it doesn't look like it.


Clean Package
The Öhlins TTX's for the R8 do not have a remote reservoir to package

Technical Support
Rarely needed, but my 27 year chassis/vehicle dynamics design and development background, while developing what we sell on our Audi R8 V10, results in unmatched technical support of our aspect of what we sell. Our detailed chassis/vehicle dynamics experience, as well as the R8 specifically, helps our customers get the most out of our systems.

 

[Scott-AhlmanPerformance]

I do have to confess the only R8 I've driven is mine, so for all I know, the setup is terrible, but just better than anything else I've driven because it did start life as an R8. I haven't tried adjusting the dampers yet. I have driven it less than a thousand miles, so I feel like I'm still jelling with the car and figuring out what my current baseline is like. Schedules were such I didn't meet the prior owner, but the dealer involved knew him and the car fairly well, and commented that he personally would soften it up a little. It hasn't struck me as too firm, and I like the fact it does feel very solid. I haven't had any sensation that a lack of compliance has caused grip issues, but I also have been on pretty decent roads. So I haven't tweaked yet, but it's been in the back of my mind.

Good catch on the Eibach spring in the manual! I had to go back and poke around to see where you had picked that up. My springs are actually branded as Bilstein, and the part numbers match the manual. I must be a car nut, because I just happened to take some pictures of them while scoping out ball joint sizes last February. I was hoping to see a number that would ID rates, but I think all I am finding is a manufacture date and the part number that I can't find any detail on. Picture of a rear one attached.

I must say I like the accessibility of the adjustment dials of the Ohlins, and if I was at ground zero, I'd have to be looking at them pretty hard. As it is, from all I know of Bilstein and can scope out on their Clubsport line, I should be in pretty good shape, and I'm pretty happy the owner went this route when the mag ride decided to leak. Definitely considered them a "plus," as I was comparing this car to others on the market at the time.

Thanks for all the feedback on this stuff. I really appreciate your track and design experience and time to engage in delving deeper into chat here on items like this. I got bit by the car bug about 50 years ago as a little guy handing my dad wrenches while he worked on prepping his Formula Vee. I think some of this car stuff must be in the DNA.



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If you like the steering, ride and handling of them on your roads then you are in good shape. Especially if you are not losing traction/grip. They are a quality coilover, as I note.

Unfortunately the part number does not appear to tell us the rate, but the 04/16 tells me there is a good chance the front springs are 16 Kgf/mm which is very close to 160 N/mm. This makes sense to me based on lowering ability stated with the kit. If this is the case the rears are likely close to that rate. And if you had rough roads then to us this would be too aggressive for the street and you would lose grip often as well as hear additional creaks in the car at times. So I am not positive on that rate, but it makes sense to me and if so I am glad the suspension works well for your normal driving.

Understood on adjustability. I get it. If it is working for you then that is what matters. But id you decide you want to see where the adjusters are set and adjust them I am glad to help and you can send me a PM or phone call. We don't sell or support Bilstein, but it is a good brand and I am curious to understand their adjustability. I agree with your assessment as these being a "plus" versus many options for the R8.

Absolutely, glad to give it. I am fortunate I was born on the chassis/vehicle dynamics and speed path and knew it very young. That is awesome you had the car bug and exposure at a very young age and get to enjoy it on such a great car.

 

[Scott-AhlmanPerformance]

That is actually a rear spring I posted above. Below is the front, and as you can see, it's marked 34/15. Does this make more sense as to position (on the car) and spring rates?

Thanks again. Really appreciate your offer to help dial these in (and may take you up on that in a bit.) If I could figure out how to send a cold one via PM, it would be next to your mouse right now.



View attachment 268934

Ah yes, my mistake...should have seen the first pic coilover going to the knuckle...rear.
yes 150 front and 160 rear is quite possible. Others are 160 front and rear. The little higher rear is decent for ride with the weight distribution, but there are tradeoffs for power down and grip in general. The stock Gen 1 R8 is very noticeably softer front and rear - more so the rear. If the damping matches the spring rates, as I suspect they do here, then that is good.

You are most welcome. All good. Any time.