[Bee Pee]

Originally Posted by Watsey

Cheers Terry

Using the OEM top mounts the front end has -0.48/-0.52 L/R respectively.

Center Gravity is suggesting -1.25 -1.50 as a sensible range for road use, and talk it through with them again when the camber plates are fitted.

Watsey,

If trying to achieve -1.25 to -1.5 deg front camber, camber plates can be noisy.

To minimise NVH, you could always consider a combo of upgrading F31 LCA's with S'pro camber adjustable bushes - to match those fitted to yr tension struts - plus swap hub carriers for -30min versions, part #'s L&R 31216854199 & 31216854200

http://www.realoem.com/bmw/enUS/part...&q=31216854199

Just a suggestion.

BP

[Tengocity]

Originally Posted by Watsey

Cheers Terry

Using the OEM top mounts the front end has -0.48/-0.52 L/R respectively.

Center Gravity is suggesting -1.25 -1.50 as a sensible range for road use, and talk it through with them again when the camber plates are fitted.

Ok. I am interested to look further in to this if it really does help with the understeer. I guess it's more at the limit as the issue with McPherson struts over say double wishbones (as I understand it), is maintaining the right camber when more lock is applied, especially as more roll develops (which is does with a 6 pot diesel engine up front).

Having said that, it's not too often an issue on the roads, and I'm hoping not to be using the 335d for track use anymore, so I should leave it as is!

Getting to -1 would be good though, and I was able to get -1.16 with the Boxster on standard top mounts and LCAs. Really helps with the steering response, and will really help the tyre life on track.

[Tengocity]

Originally Posted by Bee Pee

Watsey,

If trying to achieve -1.25 to -1.5 deg front camber, camber plates can be noisy.

To minimise NVH, you could always consider a combo of upgrading F31 LCA's with S'pro camber adjustable bushes - to match those fitted to yr tension struts - plus swap hub carriers for -30min versions, part #'s L&R 31216854199 & 31216854200

http://www.realoem.com/bmw/enUS/part...&q=31216854199

Just a suggestion.

BP

What's the rough cost of this and is doable on an xdrive car?

[Tengocity]

Originally Posted by Watsey

SuperPro caster-adjustable front bushes to replace the very soft rubber compliance bushes presumably required for NVH due to OEM run flats. Given the wear on the inside edges of the front tyres Center Gravity suspected that the soft compliance bushes were allowing the front tyres to toe-out at speed, causing the wear. The fronts (MPSS) have done 30K miles, which includes two track evenings, so they’ve held-up very well.

Vorschlag camber plates - these will be installed in a few week's time to get some more camber into the front end which should help reduce understeer. They aren't fitted yet as Vorschlag shipped them late - I'm not at all happy about that - I wouldn't use them again. I won't be going for an extreme camber, but 1.25-1.5 degrees should help.

Can you tell me more about these bushes? Cost and hassle to fit?

[Bee Pee]

Originally Posted by Tengocity

What's the rough cost of this and is doable on an xdrive car?

Tengo,

Yes Realoem shows -30min correction hubs for 335Xd

L&R part #31216856535 & 31216856536



http://www.realoem.com/bmw/enUS/show...95#31216856535

Cost-wise - cheapest oem parts delaers in Uk are Cotswold Bmw [Phil Ennis] and Harry Fairburn [Scott Murray] - give either of them a call to gauge pricing....

BP

[Bee Pee]

Originally Posted by Tengocity

Can you tell me more about these bushes? Cost and hassle to fit?

Tengo

Powerflex website for F3x

PFF5-1901G - caster adjustable & PFF5-1902G camber adjustable

S'pro website for F3x

SPF4306K - caster adjustable & SPF4303K camber adjustable

BP

[Watsey]

Originally Posted by Bee Pee

Tengo

Powerflex website for F3x

PFF5-1901G - caster adjustable & PFF5-1902G camber adjustable

S'pro website for F3x

SPF4306K - caster adjustable & SPF4303K camber adjustable

BP

Of those options the very strong recommendation to me from Center Gravity was for SuperPro. The helical grooves machined into the metal components, plus the grease provided, is vastly better than Powerflex. They've ever only had one SuperPro bush that's needed re-greasing.

[Watsey]

Originally Posted by Bee Pee

Watsey,

If trying to achieve -1.25 to -1.5 deg front camber, camber plates can be noisy.

To minimise NVH, you could always consider a combo of upgrading F31 LCA's with S'pro camber adjustable bushes - to match those fitted to yr tension struts - plus swap hub carriers for -30min versions, part #'s L&R 31216854199 & 31216854200

http://www.realoem.com/bmw/enUS/part...&q=31216854199

Just a suggestion.

BP

Thanks BP.

Center Gravity discussed this with BMW (I accept that BMW Parts Dept may not be the world authority in terms of knowledge of BMW parts) and was told that the arms wouldn't fit.

This, plus the fact that the resulting camber would be fixed, led us to adjustable camber plates.

One benefit of the caster-adjustable SuperPro bushes is that you get camber for free as lock is applied - I'll be trying to feel whether this makes a real difference as I spend more time in the car.

[Bee Pee]

Originally Posted by Watsey

Thanks BP.

Center Gravity discussed this with BMW (I accept that BMW Parts Dept may not be the world authority in terms of knowledge of BMW parts) and was told that the arms wouldn't fit.

This, plus the fact that the resulting camber would be fixed, led us to adjustable camber plates.

One benefit of the caster-adjustable SuperPro bushes is that you get camber for free as lock is applied - I'll be trying to feel whether this makes a real difference as I spend more time in the car.

Watsey,

Not suggesting new arms, use yr existing F31 LCA's but retrofit S'pro camber adjustable bushes into them. Gives o/a ~ 1 deg of adjustment - cheaper and more NVH friendly than camber plates.

The hubs are oem upgrade part to add more camber to get you into -1.25 to -1.5 deg range w/o noisy camber plates...

BTW - BMW parts guy is talking tosh - I have F8x TS and LCA on my m135i - they fit and work just fine !!!

BP

[NISFAN]

Hey Ian, I have been talking to Bilstein DE technical this week, discussing the various options.

Apparently their PSS10 B16 kit has 100N/mm rear springs. And the comfort version is 70N/mm. I am not sure how they measure that, as of course the Bilstein springs are progressive. From talking to the engineer I think they ignore the progressive first stage, so the first half in could be lower than the above figures.
Seems strange as you are saying stock rear springs are about that level (comfort version), and I feel the Bilsteins definitely feel stiffer. Maybe the damper gives that impression.

But holy hell, your Ohlins are significantly stiffer. How are you finding driving comfort? Do you think they could have been softer?

[Watsey]

Originally Posted by NISFAN

Hey Ian, I have been talking to Bilstein DE technical this week, discussing the various options.

Apparently their PSS10 B16 kit has 100N/mm rear springs. And the comfort version is 70N/mm. I am not sure how they measure that, as of course the Bilstein springs are progressive. From talking to the engineer I think they ignore the progressive first stage, so the first half in could be lower than the above figures.
Seems strange as you are saying stock rear springs are about that level (comfort version), and I feel the Bilsteins definitely feel stiffer. Maybe the damper gives that impression.

But holy hell, your Ohlins are significantly stiffer. How are you finding driving comfort? Do you think they could have been softer?

Hi Gordon.

From what I found online the OEM stock rear springs are 460-480lb/inch. The figures seem to vary.

Also found an online conversion of 5.7x for N/mm to lb/inch. So Ohlins 160N/mm rear springs equate to 912lb/inch. They are linear, which makes that bit easy.

2x OEM might sound like a big jump, and there's no mistaking the increase (it does feel a lot firmer), but compared to the feeling of a very heavy rear on stock springs (especially coming off shallow speed bumps, or along a bumpy B road), it's so much better.

Center Gravity set the dampers at 12 from full stiff (same for front and rear) and reduced the ambient tyre pressures from my normal 2.5 to 2.4 On smooth tarmac 12 was fine but was giving a fidgety ride on uneven roads so I've backed them off to 14 and increased tyre pressures to 2.6 as I didn't want the tyres to make compromises for the suspension. 14 is proving to be a good compromise but I'll be reverting to 2.5 Bar front and rear as I can just feel that the tyres are a tad on the hard side. I'm still running MPSS.

Going from 12 to 14 makes a noticeable difference and I plan to make gradual and subtle changes rather than big jumps in settings. It's too early for me to tell how much of the much firmer ride is from the springs and how much is from the dampers. Given the excellent control over fast undulating roads, certainly far better than I am used to with the OEM adaptive, I suspect that the dampers are still a significant part of the firm ride. If I set them to full soft I expect the car would pogo all over the place with the updated springs.

Two things are clear in my mind.

Firstly, I don't miss the EDC at all - I far prefer the passive setup and getting to know what it can and will do across a variety of road surfaces. Having to adjust EDC settings on the fly was very distracting.

Secondly, the Ohlins dampers hugely more capable than OEM - OK, that may be obvious, but you can really feel them working in compression and rebound, and the car just feels planted all the time.

The ride is very firm (I'm going to have to reduce the sensitivity setting on my ThinkWare dash cam as it keeps thinking I've crashed !) but I have to qualms about that as a compromise compared to the wallow that I was still getting with the hybrid setup.

Combined with the SuperPro bushes I now find that the car will hold a line through bumpy sweeping bends, rather than me having to constantly adjust the steering inputs, making it far easier and more enjoyable to drive.

I thought carefully about a coilover setup with progressive springs but got drawn to the Ohlins after a lot of research and also Center Gravity recommendation when we discussed my driving style and the types of roads I enjoy when my car had its suspension/geometry health check as a preliminary visit.

There's an open door if you want to try/compare.

[NISFAN]

Originally Posted by Watsey

Hi Gordon.

From what I found online the OEM stock rear springs are 460-480lb/inch. The figures seem to vary.

Also found an online conversion of 5.7x for N/mm to lb/inch. So Ohlins 160N/mm rear springs equate to 912lb/inch. They are linear, which makes that bit easy.

2x OEM might sound like a big jump, and there's no mistaking the increase (it does feel a lot firmer), but compared to the feeling of a very heavy rear on stock springs (especially coming off shallow speed bumps, or along a bumpy B road), it's so much better.

Center Gravity set the dampers at 12 from full stiff (same for front and rear) and reduced the ambient tyre pressures from my normal 2.5 to 2.4 On smooth tarmac 12 was fine but was giving a fidgety ride on uneven roads so I've backed them off to 14 and increased tyre pressures to 2.6 as I didn't want the tyres to make compromises for the suspension. 14 is proving to be a good compromise but I'll be reverting to 2.5 Bar front and rear as I can just feel that the tyres are a tad on the hard side. I'm still running MPSS.

Going from 12 to 14 makes a noticeable difference and I plan to make gradual and subtle changes rather than big jumps in settings. It's too early for me to tell how much of the much firmer ride is from the springs and how much is from the dampers. Given the excellent control over fast undulating roads, certainly far better than I am used to with the OEM adaptive, I suspect that the dampers are still a significant part of the firm ride. If I set them to full soft I expect the car would pogo all over the place with the updated springs.

Two things are clear in my mind.

Firstly, I don't miss the EDC at all - I far prefer the passive setup and getting to know what it can and will do across a variety of road surfaces. Having to adjust EDC settings on the fly was very distracting.

Secondly, the Ohlins dampers hugely more capable than OEM - OK, that may be obvious, but you can really feel them working in compression and rebound, and the car just feels planted all the time.

The ride is very firm (I'm going to have to reduce the sensitivity setting on my ThinkWare dash cam as it keeps thinking I've crashed !) but I have to qualms about that as a compromise compared to the wallow that I was still getting with the hybrid setup.

Combined with the SuperPro bushes I now find that the car will hold a line through bumpy sweeping bends, rather than me having to constantly adjust the steering inputs, making it far easier and more enjoyable to drive.

I thought carefully about a coilover setup with progressive springs but got drawn to the Ohlins after a lot of research and also Center Gravity recommendation when we discussed my driving style and the types of roads I enjoy when my car had its suspension/geometry health check as a preliminary visit.

There's an open door if you want to try/compare.

Thanks for the write up Ian, and yes I might take you up on the offer. I am having a bit of a technical hiccup with my Bilstein units, which could mean returning them. I won't say any more about that until I have the resolution from them, but if I am free to look around, I would like to consider the Ohlins R&T.

Your feeling about EDC are exactly as I felt. Worst thing about them is they form a psychological barrier for enthusiasts like ourselves, stopping people from breaking through to the other side. I see so many people hoping that just springs will solve their handling issue, and in the back of their mind thinking...surely adaptive is best?....not many missing adaptive once they are sitting in the bin.

Coming back to the heavy rear spring rate (I see Ohlins use quite a light front spring @60N/mm), I think I understand this concept now when it comes to these cars. I had fitted the rear Bilsteins to my car first of all, and due to said technical issue, the install stopped there. I then got to drive my 2 series with stock front and Bilstein rear, and immediately the rear end felt really tied down. A few days later I had the B16 fronts installed, and although the front end was more solid and controlled, the rear had lost a little of the communication I had with just the rears on. To me that tells me that these cars actually like a significantly stiffer rear spring. It's almost like the front can overpower the rears.
With my F30, I also found that running a stiffer rear damper setting also made me more 'aware' of what the rear of the car was doing.

It has been good to hear your experience. It has made me reflect on my own and has allowed me to consider another set of data, which has just slotted into place. A stiff spring rate and not too heavy a rear ARB is probably what make these cars come alive.

[Solstice1]

Originally Posted by Watsey

Hi Gordon.

From what I found online the OEM stock rear springs are 460-480lb/inch. The figures seem to vary.

Also found an online conversion of 5.7x for N/mm to lb/inch. So Ohlins 160N/mm rear springs equate to 912lb/inch. They are linear, which makes that bit easy.

2x OEM might sound like a big jump, and there's no mistaking the increase (it does feel a lot firmer), but compared to the feeling of a very heavy rear on stock springs (especially coming off shallow speed bumps, or along a bumpy B road), it's so much better.

Center Gravity set the dampers at 12 from full stiff (same for front and rear) and reduced the ambient tyre pressures from my normal 2.5 to 2.4 On smooth tarmac 12 was fine but was giving a fidgety ride on uneven roads so I've backed them off to 14 and increased tyre pressures to 2.6 as I didn't want the tyres to make compromises for the suspension. 14 is proving to be a good compromise but I'll be reverting to 2.5 Bar front and rear as I can just feel that the tyres are a tad on the hard side. I'm still running MPSS.

Going from 12 to 14 makes a noticeable difference and I plan to make gradual and subtle changes rather than big jumps in settings. It's too early for me to tell how much of the much firmer ride is from the springs and how much is from the dampers. Given the excellent control over fast undulating roads, certainly far better than I am used to with the OEM adaptive, I suspect that the dampers are still a significant part of the firm ride. If I set them to full soft I expect the car would pogo all over the place with the updated springs.

Two things are clear in my mind.

Firstly, I don't miss the EDC at all - I far prefer the passive setup and getting to know what it can and will do across a variety of road surfaces. Having to adjust EDC settings on the fly was very distracting.

Secondly, the Ohlins dampers hugely more capable than OEM - OK, that may be obvious, but you can really feel them working in compression and rebound, and the car just feels planted all the time.

The ride is very firm (I'm going to have to reduce the sensitivity setting on my ThinkWare dash cam as it keeps thinking I've crashed !) but I have to qualms about that as a compromise compared to the wallow that I was still getting with the hybrid setup.

Combined with the SuperPro bushes I now find that the car will hold a line through bumpy sweeping bends, rather than me having to constantly adjust the steering inputs, making it far easier and more enjoyable to drive.

I thought carefully about a coilover setup with progressive springs but got drawn to the Ohlins after a lot of research and also Center Gravity recommendation when we discussed my driving style and the types of roads I enjoy when my car had its suspension/geometry health check as a preliminary visit.

There's an open door if you want to try/compare.

Watsey, what size rims are you on? When I fitted KW coilovers to my M3 it was on 19" rims, changing to 18" rims allowed me to run firmer dampers without the car bouncing off the road i(well actually the traction control having a spastic attack!). It gave much better body control and the tyres seemed to iron out the smaller undulations that the dampers weren't reacting to quickly enough.

[HighlandPete]

Originally Posted by Solstice1

Watsey, what size rims are you on? When I fitted KW coilovers to my M3 it was on 19" rims, changing to 18" rims allowed me to run firmer dampers without the car bouncing off the road i(well actually the traction control having a spastic attack!). It gave much better body control and the tyres seemed to iron out the smaller undulations that the dampers weren't reacting to quickly enough.

Interesting what you have added, particularly as we know tyres may be viewed as the number one ride control component.

I'm following this thread, simply out of interest. Surely the grip level (keeping the tyres to the road) with such high spring rates is severely challenged. Reading the comments, seems ride quality is compromised.

Kevin Bird is often mentioned with his UK tuned suspension kits. I understand his approach to BMW suspension tuning has been towards softer springs and stiffer roll bars, dampers tuned to suit the typical UK roads. Certainly was with the E9x models, where he clearly blamed a lot of the poor suspension characteristics on too high a rear spring rate. His suspension guru stating spring rates are typically too high.

I suppose it depends on what we are after and where we are willing to compromise.

Will follow the feedback with further interest.

[Daftasabrush]

Originally Posted by Tengocity

Getting to -1 would be good though, and I was able to get -1.16 with the Boxster on standard top mounts and LCAs. Really helps with the steering response, and will really help the tyre life on track.

Just to butt in here, on my last set of tyres, the outer edges of the fronts were very heavily worn compared to the rest of the tyre. I'm assuming these new pivot bearings would help with that?

[Tengocity]

Originally Posted by Daftasabrush

Just to butt in here, on my last set of tyres, the outer edges of the fronts were very heavily worn compared to the rest of the tyre. I'm assuming these new pivot bearings would help with that?

Perhaps, but depends on what your current alignment is like? I've been able to get even wear on my tyres despite track use, though coilovers reduce roll considerably over standard suspension, and thats key with McPherson struts as when you get a lot of roll the impact on the geometry is impacted more than say with double wishbones.

[Daftasabrush]

Originally Posted by Tengocity

Perhaps, but depends on what your current alignment is like? I've been able to get even wear on my tyres despite track use, though coilovers reduce roll considerably over standard suspension, and thats key with McPherson struts as when you get a lot of roll the impact on the geometry is impacted more than say with double wishbones.

Yeah makes sense. My alignment is as per factory afaik, I've not had it changed that's for sure. No suspension mods either but I do like the sound of OEM improvements.

[Watsey]

Originally Posted by HighlandPete

Interesting what you have added, particularly as we know tyres may be viewed as the number one ride control component.

I'm following this thread, simply out of interest. Surely the grip level (keeping the tyres to the road) with such high spring rates is severely challenged. Reading the comments, seems ride quality is compromised.

Kevin Bird is often mentioned with his UK tuned suspension kits. I understand his approach to BMW suspension tuning has been towards softer springs and stiffer roll bars, dampers tuned to suit the typical UK roads. Certainly was with the E9x models, where he clearly blamed a lot of the poor suspension characteristics on too high a rear spring rate. His suspension guru stating spring rates are typically too high.

I suppose it depends on what we are after and where we are willing to compromise.

Will follow the feedback with further interest.

I did consider the Bird's kit but Kevin was quite clear that customers are not allowed to drive the demonstrator cars : passenger rides only.

Basically, "trust us; we've found the ideal setup". Maybe they have, but although I know Kevin's BMW expertise (Bird's fitted my Quaufe LSD) I wasn't prepared to take the gamble with a non-adjustable passive setup that I couldn't drive myself before buying.

With the R&T I know I've bought top quality damper hardware. Worst case scenario, I change the rear springs if they prove to be too stiff. So far I've no plans to do that.

[Watsey]

Some seemed interested in a follow-up write-up once I'd got some miles under the wheels, so...

With about 1,000 miles travelled since the Ohlins/SuperPro upgrade, now is a good time to let you know how the car is going. Hopefully this will give you a good impression of the difference that the upgrade has made if you are thinking of upgrading your suspension.

SuperPro caster-adjustable bushes :

The steering is noticeably tighter - a lot of the slack has been eliminated from the system and the feeling, especially through fast undulating bends, that the front wheels were moving independently of the steering inputs has been banished. Steering is now much more linear and precise - I really like the result and would definitely recommend it.

Ohlins R&T :

12, from full stiff front & rear, was fine for the journey home and the car felt absolutely planted on the motorway. However, Hertfordshire roads (and especially St Albans) are renowned as poorly surfaced and proved to be too stiff around town.

I have backed-off the dampers to 14 from full stiff, front and rear, which is proving to be a really good compromise. The set-up can still only be described as firm, and around town at say 20-30mph it still feels very firm, but there’s just enough compliance in the dampers to not feel harsh/brittle. At speed the car is still planted.

With 14 clicks 'in reserve' for the track, and feeling the noticeable difference between 12 and 14, I assume that 0-5 would need to be reserved for track only. I haven't bothered trying anything near full stiff because 12 was stiff enough.

I have tried various tyre pressures and have now settled on 2.4Bar ambient.

Damping is superb and feels excellent on the move. There is simply no ‘double bounce’ - whether it’s compression or rebound the dampers stop the movement, firmly but smoothly, at the ride height. It’s vastly better than OEM.

Spring rates. Much better compared to the AC Schnitzer units which has, along with the excellent damping, eliminated the feeling of the ‘heavy rear’. The rear spring rates are possibly just a little too high, but it’s not bothering me. We took the Sorento and the F31 camping last weekend and my car still felt brilliant despite having a boot full of stuff, so the higher spring rate has a benefit.

Driving dynamics :

The kit appears to be working well with the uprated ARBs. There’s still lateral rocking over uneven roads, but I’m happy to make that compromise.

Rear traction is massively improved : axle tramp is now pretty much non-existent in the dry and the car can get the power down so much better. The back end is now much more consistent and controllable when throttle-adjusting the attitude of the car through bends. If the rear tyres start to over-rotate through a corner the feeling is now 'smeary' rather than snap-oversteer.

This all leads to a very nice and improved cornering capability. It’s all very subjective of course, but as a package I’m very happy.

Interestingly, I don’t miss having the adjustability of the adaptive dampers at all. Getting used to the capability and consistency of the R&T builds confidence in the car, and there’s no more requirement to forever switch between Comfort/Sport/Sport+ according to the road conditions and vehicle speed.

Center Gravity :

In terms of service from Centre Gravity, and to pretty much reiterate what I said before, the team was patient, knowledgeable, helpful, attentive, and being able to talk about the car in the workshop as Pete worked on it has greatly increased my understanding of the art of suspension and geometry tuning.

The ride height is spot-on : Pete got it pretty much exactly where I asked for it to be, and the car looks great on the road. Still a Q car, but with a touch of presence. Just my opinion of course.

The car is going back to CG for the camber plates to fitted in a few weeks' time, and to have a ride height & geometry adjustment now that components will have settled as the car has been driven.

Hope that helps chaps

[dizzy619]

Nice write up mate... Definitely need a track visit ASAP to enjoy it to the full.. Tho you will spend more time tinkering than driving..

[Lancelot]

Thanks for the write up much appreciated

What are the specs of your roll bars? Birds / h&r custom made but i?m not sure what diameter that would be front and rear.

I also do subscribe to the opinion these cars like reasonably stiff bars but not too much, and stiffer springs, so as to control roll while keeping suspension independence.

[Watsey]

Originally Posted by Lancelot

Thanks for the write up much appreciated

What are the specs of your roll bars? Birds / h&r custom made but i?m not sure what diameter that would be front and rear.

I also do subscribe to the opinion these cars like reasonably stiff bars but not too much, and stiffer springs, so as to control roll while keeping suspension independence.

Glad you found it useful.

I saw your ARBs table on the main Forum suspension section. I've had the car on jacks this afternoon making some adjustments to the dampers and also fitting new HID bulbs and I could have measured the Bird's/H&R ARBs but only read your reply when I'd finished the job.

I'll try to remember to measure them and reply to your ARB post.