Bilstein B16
 

Some advice if possible,

Looking at Bilstein B16 setup because you have the damper with adjustability and it only lowers from 10mm to 25mm so will look mostly stock, where as my other option in UK is KW V3 lowers from 25mm to 50mm approx which is too much.

Spoke to Bilstein and they told me the springs are 5.4kg/mm 300lb and 6.7kg/mm 375lb does this seem harsh for 95% street driving? Have Bilstein set the rear stiffer to compensate for motion ratio?

I think the springs are progressive (unless they have changed them recently) so would they have taken and average for the spring rate?

Any help with the B16 kit much appreciated.

@Pat

No
Yes
Maybe, likely they account for approximate stiffness at static ride height as the soft portion of the coil gets taken up just by putting the cars weight on it. I found my B14s to be about as comfortable as stock with the improved stiffness for handling being a nice side effect, they have the same springs to my knowledge and the adjustability is the difference.

Here's the spring range that got published stateside but we might have a different spec than euro and your numbers might account for the bump stops as well.

Front: 2.5 - 4.5kg progressive
Rear: 3.0 - 7.0kg progressive

Personally I would definitely go with the KW V3s, 25mm lower looks nice and proportionate on an otherwise stock car. The KWs are essentially the best buy coilovers unless you're going to go all out and get Ohlins...

But to answer your question, the spring rates on the Bilsteins will be fine for daily use, especially since you aren't going very low. The stiffer rear spring rate compared to the front is standard for the GT86 platform-- I suppose to combat understeer.

The B16 kit is good and would work well for you. I'm not a huge fan of the progressive springs but it's not a big deal. They ride well. I wouldn't lower them more than 30mm. I also don't know if there's a difference between the US and UK versions.

KW V3 can definitely go lower. A little more flexible in the handling department with more adjustability and they still ride well, but it's a different feel than the Bilsteins.

- Andrew

I've had b16s for maybe 3 years. A friend of mine is the same. We both really like the setup. I had T2s before the b16s and significantly prefer the b16s. If I remember correctly Vorshlag tested the springs in their shop and found the fronts were nearly linear. The rears were progressive however in a way that made it seem like there was a helper spring that compressed for the first part of the travel (at rest), then had a linear rate the rest of the way. I would not let the advertised progressive spring rate dissuade you. Hopefully Andrew has some insight on this as well. Before I bought them I was hesitant due to the advertised progressive spring characteristic, however after ownership of them it is simply not an issue.
As Andrew said, they feel different than v3s. Monotubes have a certain feel that is different than twin tubes. I significantly prefer monotubes because of this however they are not as comfortable at low speeds (i.e. parking lots). I think they are much better at highway speeds though. I should say this statement is specific to b16 versus v3s.

Thanks for the help all, good to get a range of views

I made a mistake with the spring rate, a small change to the information.

Bilstein B16 UK
4.5kg/mm 252 lb
6.5kg/mm 363 lb

Looking at the image the springs do look more linear at the front as you say.

For me I would likely fit and forget and possibly only turn the adjuster at a track day, and not having to dial in compression and rebound and test is a bonus with the Bilstein one way adjustment. I have had B6 dampers on other cars and don’t mind the ride around town or the improved highway driving knowing its partly a characteristic of monotube.

KW and Ohlins (please correct me if wrong)

KWv3
4kg/mm 224 lb
5kg/mm 280 lb


Ohlins (2020 details)
5kg/mm 285 lb
5kg/mm 285 lb

RCE T2 Clubsport
7kg/mm 400lb
7kg/mm 400lb

I am of the belief that the KW V3 may be softer over small bump with its clever valve twin tube system, but I would need to drop it lower to start with and I really want it as stock looking as possible, (due to the wheels looking very sunk in and even more with the min drop from KW). Spacers are not an ideal option for me as I don’t want to move away too much from factory spec suspension i.e. scrub radius effects etc. KW Looks good but I kind of ruled them out only due to my personal requirements above. The Ohlins R&T would have been considered, if they had some consistency on spring rates, many seem to want to change the springs, and in the UK at least some talk about running out of travel over big bumps. Changing springs on a £2500 kit to get it right is not something I want to look into.

With the 3 options I have been leaning toward the Bilstein due to its 10mm starting drop, and I think you have helped to confirm that it’s not a bad option for my requirements. :thumbsup:

Over Christmas (that seems like a long time ago) I didn't buy anything and with everywhere in lock down I can't see myself doing anything soon.

But while i'm thinking about this.
The standard spring rate on a 2019 car are lower than the 2012 car but with higher sway bars? Is this correct? So the 2019 spring rates might be about 3kg approx?

If this is the case looking at the Ohlins again they would seem like a nice supple upgrade or have I calculated it wrong? Am I right in thinking they are also mono tube like the Bilstein?
If both the bilstein and Ohlins can drop as little as 5-10mm approx, but would you say the Ohlins is a better damper compared to the Bilstein? Is the Bilstein a more robust but harsher damper in comparison?


https://www.ohlins.eu/images/db/high...g-00000608.jpg

Ohlins lowered the rates once with their MP20 R&T product and now they offer again a bit higher rate with the MP21 product. I believe that you have now the option to chose between 4kg/3kg, 4kg/4kg, 5kg/5kg rates. A bit silly for me, since they are supposed to be the experts. Why to leave the customer to choose? This product is not directed for professionals ...

Ohlins and Bilstein are a mono tube design in front. The rears are twin tubes like the OEM ones. The only vendor I am aware that offers mono tube front and rear is the Sachs performance coilovers (not the ones offered in PP and tS cars). However, they have other issues.

I agree I would like them to have tested endlessly for the given set up of R&T.


Interesting that they both have twin tube rear, not a problem for me just curious. Don't know much about the Sachs in comparison to the Ohlins or Bilstein in terms of spring rates or performance, is it a popular set up in Germany perhaps?

Not very popular in Germany. They created them basically for the Japanese market. I tried them because I could find them very cheap, but I sold them afterwards.

Ohlins R&T and Bilstein B16 use monotube rears.

Both are quite good and we have experience with both. The drawback to the ohlins is the softer rates don't work super well with the limited travel. The drawback to the Bilsteins is the progressive rear spring isn't ideal for everyone.

Again both are really good shocks for a fun street car. They have limitations like most other things but do a good job overall.

- Andrew

Yes you are right. Ohlins R&T and Bilstein have both front and rear mono tubes. I wanted to say that only the front are inverted and I was confused.

No worries.

A refresher for everyone:
https://www.instagram.com/p/B7qn-gnn...d=xw2vnir9xxs4

Another advantage of inverted shocks not mentioned in the article I wrote above is a slight reduction in unsprung weight (and thus more spring weight instead). It's almost always a strut that's inverted since they benefit from the increased strength, but you can mount a shock upside down too but that's pretty rare.

- Andrew

*If you had to choose, which one would you be looking at? The fit and forget B16 or Ohlins with uprated springs to ... lbs/Kg?

*If you had a GT86 for occasional fun driving/European road trips 95%, 5% track days.