Coilovers thoughts / experiences

[Sammo 2544]

So, not being satisfied with my new lowering springs and shocks (height not where I want it / still a bit soft) means I'm looking to go for Coilovers.

I want to get my car sitting exactly where I want it (although not going particularly low) and make the car a bit more go-kart like without wrecking the ride quality - don't mind it being stiffer and firmer but prefer not to be crashy and noisy.

The fact I need to certify my cars manual swap anyway helps the 'justification'.

Options I'm looking at are:

BC Racing BR - $1600 -  ubiquitous in NZ / support / value / can get supplied, installed, aligned and certed in one hit @Hyper which is very attractive if there are any issues. Also like their threaded shock body design which retains suspension travel at various heights (or just marketing, I'm not sure). Reservation is their image is more JDM drifter boi and heard the pillowball mounts can get a bit rough / noisy. 

XYZ - $1550 -  Local source (Speedfactor) although would need to get end-links and install myself - not sure if they are meaningfully different quality-wise to BC either? They have a rubber base pillowball that apparently helps NVH.

Or look at importing some German ones (better quality / damping and ride??) via DC Performance in the UK and try installing myself, using my existing new OEM shock / strut mounts:

ST X - $1650 landed - no top mounts / no damping adjustment - these all appear to lower via compressing the spring (impacts ride quality as you go lower?)

ST XA - $1950 landed - no top mounts but with adjustable dampers (potential happy middle ground)

KW V1 - $2000 landed - ST X but better build quality

KW V2 - $2550 landed - ST XA but better build quality

Eibach Street Pro / Bilstein B14 - around $2000 landed but no damping adjustment and less reviews around

The BC Racing and XYZ come with Camber pillowball mounts which I'm unsure I actually need to obtain cert (cert requires camber to be within 0.5 of factory specs?) but sound like they transmit a fair bit of NVH as well.

Keen to hear your thoughts on what you've used and any experiences you've had.

At this point I'm planning on owning the car a long time so spending a bit more on quality isn't an issue - only if it brings a real world benefit of course.

 

 

 

[///M 22]

I've currently got ST X coilovers on my 130i and I have nothing but good things to say. They're quiet, comfortable and provide noticable handling improvements. I have no regrets and would purchase them again. It's worth noting that the ride comfort (with these coilovers) is depedent on how much you lower your car. If you want it slammed, it's going to feel terrible. My car's about ~340mm hub centre to arch and it's perfect imo. 

Eibach pro street s coilovers are very similar to the ST-X/KW V1 (same basic damper) but sprung and valved to be slightly more comfortable. They're also SS.

Edited August 20, 2020 by ///M

[Sammo 2544]

@///M Thanks mate - awesome, cheers for that.

Yeah, it looks like most of the German coilovers have that design , compressing the spring. I'm not looking to slam, just have tyre just above the arch (probably 30mm from stock Msport height) so hopefully in the middle of the designed lowering range.

Did you import the ST-X yourself? Any issues with certification without camber plates / ability to dial out the natural negative camber from lowering?

[///M 22]

That would probably be in the middle of the designed lowering range, however I'd ceck out the TuV data sheet to confirm. Some of the coilovers you listed might get you lower without having to compress the spring too much.

I purchased the coilovers from demontweeks in the UK. Shipping relatively quick. No issues with cert- the alignment settings were near enough stock (due to the height). I added M3 camber arms which put me close to the e92 M3 settings.

[Matth5 471]

I have KWV2 in the 335i, and honestly I think their existence is entirely pointless between V1 and V3. I couldn't see the point in adjusting rebound on it's own because pretty much any setting besides the recommended default was bad, so I may as well have had V1s.

It was the last owner that had them installed anyway though. Besides that, they're excellent, that car has awesome handling while still being decently comfy. 

[Herbmiester 925]

I had Ohlins Road & Track on my E46 and they were excellent. 

[Sammo 2544]

@Herbmiester I bet they were ?

$5k though ?

 

[Sammo 2544]

@Matth5 Good feedback, and interesting point.

I definitely like the 'idea' of damping adjustment but understand on the KW V1 its set up out of the box from chassis specific testing by much smarter people than me, so likely better than a lower quality kit with lots of things to adjust (i.e. mess up!).

[Sammo 2544]

Jeez, looks like 8 weeks lead times from KW at the minute...

Although to be fair, even 'local' option BC was going to be 6 weeks...

[Gaz 1061]

I've got BC Golds in the e36 and Yellowspeeds in the e30 and like them both. Tyre size I found makes a massive difference to how the they ride/crashing etc

[Herbmiester 925]

I would go KW, Boytie had a set on his E60 and the ride handling compromise was very good. He did find raising the ride height from Flat Peak slammed to lowish made a huge difference to how it rode with no effect on handling. I will say setting my E46 330ci super low was a disaster. 

[Sammo 2544]

@Gaz How is the ride and NVH on the BCs?

I'm running 235/40/18 so have a little bit of sidewall.

[leichtbau 525]

1 hour ago, Sammo said:

Jeez, looks like 8 weeks lead times from KW at the minute...

Yep! I've had KW Classics in E30 M3 spec on order for a few weeks now, but I'm in no rush.

Regardless of my choice of KW's for the above, I'd go with KW anyway, purely because you can ask them to set them up how you'd like(spring rates) before they ship. It's well known that our main state highways are goat tracks compared to most developed nations, so some softer spring rates is not a bad thing to ask for. Bilstein coilover systems are bloody awful in NZ conditions.

5 hours ago, Matth5 said:

I have KWV2 in the 335i, and honestly I think their existence is entirely pointless between V1 and V3.

Not entirely pointless - you can set a certain amount of pitch and roll using the damping adjustment.

 

As a general note, I'd avoid any coilover system that doesn't utilise a tender spring unless you like your fillings removed.

[Sammo 2544]

@leichtbau tender spring being that little 'helper' spring?

I did see the KW V1's offer 2 types for the front axle - 2 piece race spring (helper and linear?) or one piece (progressive?) 

[leichtbau 525]

35 minutes ago, Sammo said:

@leichtbau tender spring being that little 'helper' spring?

I did see the KW V1's offer 2 types for the front axle - 2 piece race spring (helper and linear?) or one piece (progressive?) 

That's it yep. Using my suspension on order as an example... The tender is rated for 20Nm/mm and binds first, before becoming a solid section of the suspension under higher loads where the 70Nm/mm linear spring takes over. The advantage is that during your shopping run, the tender is absorbing all the bumps. This is all fine and dandy for a McPherson strut up front like every BMW since the 70's has, but in the rear it's a whole other kettle of fish, and that's when you'll see beehive springs used as a progressive spring compared to a linear one.

Jump onto the KW website and have a chat with their consultants about what you want - they know their sh*t.

Edited August 20, 2020 by leichtbau

[Gaz 1061]

28 minutes ago, Sammo said:

@Gaz How is the ride and NVH on the BCs?

I'm running 235/40/18 so have a little bit of sidewall.

I've got no problem with it, if it's a rough shitty road then you'll know about it and youll learn where the pot holes and bumps are quickly, i am rather low however. Swapping between 215/35/18 to 215/45/17 made a massive difference in harshness. 

See if you can go for a ride with someone who has them installed, on the roads you are used then go from there. Just make sure they have been set up correctly as that can make a massive difference in ride quality

[Bandit 194]

Check the Demon Tweeks website for best global pricing in $NZ dollars to your door in double quick time. Recommend them over DC Performance based on experience with global shopping.

And Evan Pittman and his guys are a good team Evan is well thought of in the various Renn Sport race series, they would supply links etc I'm sure if asked. Should you choose to go down this track may I suggest Speedfactor do the fitting too.

KW branded product has stainless moving parts, the ST has innox, so susceptible  to corrosion, no real deal breaker here in NZ firstly because of our climate, secondly we are putting good bits on our "toy" or hobby cars that rarely (in my garage anyway) see rain.

In Auckland you chaps are lucky to have Ray at Hell BM on your doorstep, he has vast experience in all facets of suspension and mechanical, in fact his knowledge bank is greater than than the sum of the contributors to your post combined.☺️

Personally our M cars mostly have ST X /XA  and Koni / Eibach Pro, and years ago Ray did influence my thinking here.

Edited August 20, 2020 by Bandit

[Sammo 2544]

@Bandit Thanks mate!

I had a bad experience earlier this year with Demon Tweeks (Parcel Force delayed, then lost package and Demon Tweeks support throughout was really poor) having said that, most of the issue was their carrier, Parcel Froce and to be fair, it was right in the middle of Covid's first wave.

I've not used DC Performance, but they have been very responsive to email questions to date at least - prices seem comparable (product dependent).

Definitely leaning towards either KW V1 or ST XA at this point (similar price - basically brand appeal vs rebound adjustment...) 

Car is driven in rain about 7000km a year  but no salted roads up here so I imagine ST would be totally fine.

[Sammo 2544]

@leichtbau Cheers, that makes sense - essentially a dual rate spring system.

The likes of BC, appears you are straight into the 8kg linear spring with a monotube damper which sounds harsh.

I'll have a chat to KW support, I've found them helpful in the past and they seem more than happy to discuss both KW and ST products impartially

[JohnM575 112]

To throw another local option in the works, have you thought about giving George Stock (Koni) a call to discuss a suitable coilover kit? I know they have made a coilover for the BMW Race Series E46's at the moment. I'm sure they could valve the shocks for road application and would pair with appropriate spring rates. Russell at Koni looks after my shocks in my race car, and supplied me with adjustable Koni Sport shocks for my E46 Touring. Good guy to deal with. 

 Images pulled from the George Stock & Company FB page below:

Edited August 20, 2020 by JohnM575

[Matth5 471]

11 hours ago, leichtbau said:

Not entirely pointless - you can set a certain amount of pitch and roll using the damping adjustment.

Everytime I veered off the default settings they just felt awful. Any softer and the car would bounce. Any stiffer and it felt very harsh and just not very settled. I'm sure that would have been fixable if compression could be adjusted to suit. And I only adjusted by one or two clicks.

Maybe one click on front or rear to adjust balance would work well. But not worth the extra cost of the V2s.

Default felt absolutely perfect like it was designed for the car, and I imagine V1s would be locked to the same setting. 

[///M 22]

Agree with Matthew, if you want the V2s you may as well spend a bit extra and get the V3s. The KW V1/ST-X are at KWs recommended settings and if you set the ride height appropriately they’re a great dd/’fast road’ coilover.

MCA coilovers are also worth a look. They’re good quality and made in Aus so the shipping should be reasonable.

For me, bang for buck, the ST line can’t be beat.

Edited August 20, 2020 by ///M

[Sammo 2544]

@///M Cheers - how long have you had your STs and presume they are holding up without any corrosion?

Need to get my car on a flat surface and get my wheel to hub measurements and ensure my goals are comfortably within the range on the TUV / install guide.

My wheels are 18x8.5 ET30, so would imagine I will have no clearance issues.

 

[///M 22]

Not too long- they've only been on for a few months and look great. As others have said, we shouldn't any major corrosion issues with our climate. I can live with some surface rust if it ever gets to that stage.

Also, it's worth keeping in mind that coilovers are a wear item and you'll eventually need to rebuild them or purchase a new set. If the surface coating can last till this stage is it worth spending more for the shiny stuff?

I'm only planning to keep my little 130i for another 3 years or so before moving to something else so I'm pretty confident the ST coilovers will be able to see me over with no issues 

Edited August 20, 2020 by ///M

[Sammo 2544]

@///M The lure of shiny stuff is real haha