Coilovers: BC Racing DS DA vs Bilstein B16 PSS9 help me choo

[Jt23]

Opportunity has come up for me to source my coilovers at cost price after delaying purchase last year. I'm down to 2 options - after a final steer to help me choose. Price not really a factor.

Car sees road and track but is a weekend and track day toy only. Looking for reasonable road manners with good track performance. It's an e86 z4 3.0si Coupe 2008.

BC Racing DS DA, 8KG front, 10kg rear (leaning towards these)

Pros:
Digressive piston, pillow ball fronts with rubber mounted rears, and adjustable camber plates as standard

Custom spring rates, flexible for changes later

Generally seems more customisable

Cons:
More budget option option/lower build quality, but I know bcs are still pretty well rated by users

Does 30 clicks of adjustment feel excessive vs 9 on the bilsteins? Wondering if ill end up preferring less clicks and more noticeable adjustments

Bilstein B16 PSS9 (like the quality but have some hangups)

Pros:
Primarily build quality and brand rep

High quality inverted monotube

Cons:
Does not come with adjustable top mounts and solutions will be aftermarket - unclear what will fit

Bilstein don't seem to share their spring rates/seem less customisable

No digressive valving and have heard feedback billies can be very stiff and bouncy on these cars from quite a few users, not so tolerable on road

[danb79]

For what it's worth I ran Bilstein B14s on my previous 130i LE which was built as a fast road car and they were superb. Firmer, but not stupidly and took the very rough unloved local country roads here in Lancashire.

I rated them so much I've just had them fitted to my E39 540i and very much the same feedback - firmer but not teeth rattling, take the roads really well. But smooth & compliant when driving normally

If the B14s are like that I can only see the B16s being better due to their full adjustability

I wouldn't run BCs personally. They're budget coilovers and suit budget builds.

Have you looked at KWs and/or STs?

[Jt23]

Cheers, good to hear that rough b road quality was OK as I like a good b road bash, it's one of the reasons the digressive valving on the bc attracted me.

I started out looking at kw v3 but eventually decided I didn't want two way adjustment for now, rather keep it one way.

Currently I have a deal with a local motorsport store to get warehouse price after helping them with their website, and out of their range these are the two coilovers I'll be choosing from. They have these, ast (out of price range) and kw but already decided against the latter for ease of setup.

I think main headache for me at the moment with the bilsteins is getting adjustable top mounts, if I could get pillowball top mounts with adjustable camber/caster that would probably tip the scale, but I'm unsure what's available for this coil and car combination on that front

[8Tech]

Bilsteins all the way. BC Racing are decent enough but for build quality and development time, Bilsteins.

[Trev450]

Another thumb's up for the Bilsteins.

BC's are a budget coilover and feel like it. The 30 clicks of adjustment is a waste of time because there is very little difference once you get over about 15-20 clicks, KW and Ohlins have around 7 clicks and they do very well with that.

[aeropilot]

Trev450 said:

The 30 clicks of adjustment is a waste of time because there is very little difference once you get over about 15-20 clicks, KW and Ohlins have around 7 clicks and they do very well with that.

Exactly.
More adjustment is just extra fluff, unless full on track use trailer queen, and you've got the time and facilities to make use of that.

As yes, Billy's for me everytime.
Only issue is the spring rates for out of the box Billys, which are not great for UK B roads, usually too stiff.

I had the Birds B1 suspension kit fitted to my E82 135i coupe, which was Billys and custom designed springs for UK roads, and it was better on UK B-roads than the OEM M-Sport setup (which was way too stiff and under damped)
It needed the stiffer anti-roll bar setup from Birds though if taking it on track, but it was a road car not a track weapon.

[danb79]

aeropilot said:

Trev450 said:

The 30 clicks of adjustment is a waste of time because there is very little difference once you get over about 15-20 clicks, KW and Ohlins have around 7 clicks and they do very well with that.

Exactly.
More adjustment is just extra fluff, unless full on track use trailer queen, and you've got the time and facilities to make use of that.

As yes, Billy's for me everytime.
Only issue is the spring rates for out of the box Billys, which are not great for UK B roads, usually too stiff.

I had the Birds B1 suspension kit fitted to my E82 135i coupe, which was Billys and custom designed springs for UK roads, and it was better on UK B-roads than the OEM M-Sport setup (which was way too stiff and under damped)
It needed the stiffer anti-roll bar setup from Birds though if taking it on track, but it was a road car not a track weapon.

Haven't found the B14s on either my previous 130i or current 540i to be of any issues at all... Yes, firmer, but not jarring or filling-loosening etc

I'm surrounded by unloved / untreated country roads and single track lanes here in Lancashire

I've been nothing but impressed with them and from my cars; I want comfort as well as handling