Bilstein B16

[Pat]

Originally Posted by Racecomp Engineering

The drawback to the Bilsteins is the progressive rear spring isn't ideal for everyone.

- Andrew

That was my main concern before buying the B16s from you guys. But after driving them that concern was almost entirely eliminated. What about the progressive rear springs of the B16s on an 86 (specifically) makes them not ideal for someone? I have some thoughts of my own, but would especially like to hear your detailed opinion.
TIA, Andrew.

[gravitylover]

Originally Posted by Racecomp Engineering

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

What is it about the progressive rear spring that makes the Bilsteins less than ideal? I figure it won't be long before my car needs some new suspension bits, it's at ~135k miles (but obviously not seeing much use at the moment).

[strat61caster]

Originally Posted by gravitylover

What is it about the progressive rear spring that makes the Bilsteins less than ideal? I figure it won't be long before my car needs some new suspension bits, it's at ~135k miles (but obviously not seeing much use at the moment).

Non-linear spring means you get a different stiffness at different suspension loadings, that can make the car hard to predict in various scenarios, it may act wildly differently when you hit a bump at 1.5g lateral vs. 0.7g lateral while a linear spring will largely act the same when it comes to suspension response, which is good for racecars (driver understands how car will respond and can anticipate needed correction), but probably not great for street cars (fuck I spilled my boba even though I was going slow af).

That being said, anything that uses a long bump stop in the rear will have some level of progressive spring, especially stock. Bilstein has you re-use stock bump stop so in addition to the coil spring progression you have the bump stop progression as well. If you look at the RCE T2's they have a very small bump stop that exists (mostly I believe) as a safety measure to prevent harmful bottoming. If you look at KW V3 kits they spec a softer spring and more bumpstop, even though the spring is linear their bump stop introduces progressive behavior not so different from the B14/B16.

The stock setup is pretty progressive due to some long bumpstops, if you don't hate the stock progressive spring odds are the Bilsteins or KW's wouldn't bother you. Tuned well everything works in harmony, as an average amateur odds are if you're slow on course a linear rate spring isn't going to magically make you faster, however with experience you can pinpoint areas where the suspension may not act as desired and tweaking spring rates and damping profiles can yield benefits to you as a driver.

I am interested in giving my B14's another shot, I wonder if I can get them converted to the B16 adjuster without breaking the bank...

[solidONE]

Originally Posted by strat61caster

I am interested in giving my B14's another shot, I wonder if I can get them converted to the B16 adjuster without breaking the bank...

I've not read one good thing about the Bilstein single adjustable shaft. They are not very consistent. If anything, you should be able to adapt a better 14mm adjustable shaft and bleed mechanism for less money. (taiwan) Or if its the same diameter OD shaft and stud mount for the pistons (8 or 12mm) on your megans, you can transplant. The guy that built your shocks can probably do this one hand tied behind his back.

They are 'shit' is what I've heard.

[Pat]

Originally Posted by solidONE

I've not read one good thing about the Bilstein single adjustable shaft. They are not very consistent. If anything, you should be able to adapt a better 14mm adjustable shaft and bleed mechanism for less money. (taiwan) Or if its the same diameter OD shaft and stud mount for the pistons (8 or 12mm) on your megans, you can transplant. The guy that built your shocks can probably do this one hand tied behind his back.

They are 'shit' is what I've heard.

Interesting. I've read just the opposite. When they came out with the new adjustment mechanism a few years ago they got all kinds of praise for it, and how linear it was relative to the competition. I wish I remembered where I read that, but it's out there somewhere. You may know more about this than I do, solidONE, but I have no complaints with them.

[strat61caster]

Originally Posted by solidONE

I've not read one good thing about the Bilstein single adjustable shaft. They are not very consistent. If anything, you should be able to adapt a better 14mm adjustable shaft and bleed mechanism for less money. (taiwan) Or if its the same diameter OD shaft and stud mount for the pistons (8 or 12mm) on your megans, you can transplant. The guy that built your shocks can probably do this one hand tied behind his back.

They are 'shit' is what I've heard.

Check the dates on your sources for those reviews. DG/Far North for example hasn't been involved in motorsports for about fifteen years which is the only one I can recall trashing the old Bilstein adjuster, as Pat mentions they came out with a new design about 8 years ago iirc.

Edit: and their double adjustable is legit, there was a conversion using their shafts a few years back here.

https://www.ft86club.com/forums/showthread.php?t=100216

[solidONE]

Originally Posted by Pat

Interesting. I've read just the opposite. When they came out with the new adjustment mechanism a few years ago they got all kinds of praise for it, and how linear it was relative to the competition. I wish I remembered where I read that, but it's out there somewhere. You may know more about this than I do, solidONE, but I have no complaints with them.

Is that right? Fatcatmotorsports is pretty on top of all things Bilstein. I recall him mentioning about the bleed mechanism. Was not aware they updated that long ago.

Can you link me to your source?

Take me to your leader?

[solidONE]

Originally Posted by strat61caster

Check the dates on your sources for those reviews. DG/Far North for example hasn't been involved in motorsports for about fifteen years which is the only one I can recall trashing the old Bilstein adjuster, as Pat mentions they came out with a new design about 8 years ago iirc.

Edit: and their double adjustable is legit, there was a conversion using their shafts a few years back here.

https://www.ft86club.com/forums/showthread.php?t=100216

Can you link he post? Cause I see pics of Bilstein's MDS shaft which is pretty badassed and also $500 a piece. Where is the talk about the single adjust?

[strat61caster]

Originally Posted by solidONE

Can you link he post? Cause I see pics of Bilstein's MDS shaft which is pretty badassed and also $500 a piece. Where is the talk about the single adjust?

Here's >600 page catalog from 2010 when they came out with pss10 from what I gather.

https://www.google.com/url?sa=t&sour...1vRsIo4q9fw3U9

When I talked to fcm about 5 years ago he didn't have any experience with the pss10 preferring to stick with revalving the non-adjustables.

Dynos are certainly scarce, here's one;
https://forums.m3cutters.co.uk/threa...r-sale.197264/

The criticism I've heard second hand about the current Bilstein single adjust is that it doesn't offer a wide range of adjustment and is more a fine tuning advice, at the amateur level us hack jobs sometimes need a bigger change in feel to assuage our egos that we've done something different.

[Pat]

Originally Posted by solidONE

Is that right? Fatcatmotorsports is pretty on top of all things Bilstein. I recall him mentioning about the bleed mechanism. Was not aware they updated that long ago.

Can you link me to your source?

Take me to your leader?

I read it years ago while researching my purchase decision. You're probably just as capable of doing a search as I am. Sorry I couldn't be of more help.

[Pat]

Originally Posted by strat61caster

The criticism I've heard second hand about the current Bilstein single adjust is that it doesn't offer a wide range of adjustment and is more a fine tuning advice, at the amateur level us hack jobs sometimes need a bigger change in feel to assuage our egos that we've done something different.

Huh. I don't have much experience with adjustable dampers, but I'm not a novice driver, either. I can tell you the range available with the B16 are as much as I'd ever want with the supplied springs.

[strat61caster]

Originally Posted by Pat

Huh. I don't have much experience with adjustable dampers, but I'm not a novice driver, either. I can tell you the range available with the B16 are as much as I'd ever want with the supplied springs.

Cheers to that, last we talked I don't think you had spent time playing with them yet, glad to hear you like them!

[strat61caster]

@solidONE
https://f87.bimmerpost.com/forums/sh...51&postcount=3
Found another forum post with PSS10 dynos, BMW chassis, whole thread is neat with a couple different dampers dynoed so you see some different philosophies and capabilities. Anyway, I stumbled across some S2ki posts bashing the Bilstein for an 'inconsistent adjuster' which their criticism was one click out of 10 doesn't necessarily create a 10% change in damper stiffness across the range, you get some big changes going between clicks 9 and 10 and it looks like going from say 2-3 isn't going to feel like a change at all.

As long as it's repeatable and predictable that's a decent adjuster imho, it's a damper on a budget for certain and there are sacrifices made but it's a contender.

[solidONE]

Originally Posted by strat61caster

@solidONE
https://f87.bimmerpost.com/forums/sh...51&postcount=3
Found another forum post with PSS10 dynos, BMW chassis, whole thread is neat with a couple different dampers dynoed so you see some different philosophies and capabilities. Anyway, I stumbled across some S2ki posts bashing the Bilstein for an 'inconsistent adjuster' which their criticism was one click out of 10 doesn't necessarily create a 10% change in damper stiffness across the range, you get some big changes going between clicks 9 and 10 and it looks like going from say 2-3 isn't going to feel like a change at all.

As long as it's repeatable and predictable that's a decent adjuster imho, it's a damper on a budget for certain and there are sacrifices made but it's a contender.

Rear adjustment looks a little funky toward the harder end, but the front one looks like a good spread. Maybe the amount of bleed in the shims is effecting the adjustments response, cause I cannot think of a reason why the front and rear adjustment bleed orfice and mechanism would be different. Not nearly as bad as I imagined.