[JackG]

Hi all,

I have been lurking around the forums for about a year now as I was waiting to pick up my LCI f31 335d X-Drive, and now feel it is time to come out of the shadows.

I, like many, am not overly thrilled with the standard springs although the adaptive definitely helps firm things up a bit. However, I would like to improve handling, lower the ride height and reduce body roll.

After reading through many threads it seems that the ACS springs are very highly regarded as a relatively cheap upgrade which improves all of the above. However, I have a few questions that I hope ACS users could help me with.

1) Have you had any issues with premature damper failure? Some seem to have no issues, whereas others have issues at the ~40k mark. I am not sure if this is just the dampers being poor by design or if this is an ACS spring issue. I am currently at 18k miles.

2) Some have complained about the reverse rake, but I have also read that this has been improved in the newer springs. Is this the case?

3) The garage that has been recommended to me has said that the headlights do not need to be adjusted as the LED headlights are self adjusting due to the chassis sensor, is this true?

4) Can anyone recommend where to purchase these from in the UK?

[cfm56d7b]

@jackg, what's your budget for the suspension upgrade project?

[JackG]

I don't have a set budget to be honest with you. My main concern is insurance, as with the ACS springs there is a very slight increase in premium. However, with further mods such as dampers or coil overs, this increases my premium by ~£1,000 which is ridiculous!

[Watsey]

From my extensive experience with my F31 330d over many years, the suspension is one of those things that you either a) substantially upgrade if you are interested in getting it 'right' first time (and avoid spending twice, or three times, etc), or, b) leave standard.

The first suspension upgrade to my car was exactly what you, and many others, think will provide enough of an improvement => OEM dampers + ACS springs. However, in my onion the ACS spring rates are too low (especialy for the rear) plus, and this is the biggest issue, BMW OEM dampers (especially adaptive) are shit (this is a universally accepted fact :-) ).

My advice to you is to strongly consider aftermarket suspension. If you want to retain switchable damper functionality then KW DDC is worth a look (I don't have direct experience, but a more performance-orientated damper which integrates with the OEM suspension selectability could be attractive in principle). If you are willing to consider passive dampers there's a wide range for the F31 including Ohlins, Bilstein, KW (non-EDC), etc.

If you are dead-set on ACS springs as the only modification then call Lorcan Parnell at Rossiters (01485 542000‬) or email him at acschnitzer@rossiters.co.uk. He's an official Forum sponsor and and an all-round good guy who will help you with specific advice regarding ACS, correct part numbers, recommended installers, sensible workshop installation costs (Rossiters also has its own workshop), etc.

[casualDIYer]

Originally Posted by Watsey

From my extensive experience with my F31 330d over many years, the suspension is one of those things that you either a) substantially upgrade if you are interested in getting it 'right' first time (and avoid spending twice, or three times, etc), or, b) leave standard.

My experience mirrors what Watsey is saying here. If you love your car as both a hobby and practical means of personal transport you likely won't mind the time it takes to make modifications and test. Often owners in this category have enough experience to make changes on their own, or are willing to learn, enhancing the hobbyist experience. Nothing will teach you more about your car than successfully disassembling and re-assembling parts of it. Even if you skip the DIYer part of car modification and have a shop do the work, that doesn't mean you can't enjoy modding your car, but it will cost more. In fact, multiple modifications could end up costing so much you may realise you've spent as much on a starter upgrade as you would have spent on something more advanced doing a swap only once. The cost of swapping a spring vs swapping a spring, damper, gaskets, rubber bushing, etc isn't going to be significantly different since many of these parts all need to come out to replace the spring anyway. The shop need only swap in the new parts for the old they are already removing from the car to get out the spring.

As for the ACS springs, they are very good. AC Schnitzer does sell a matching damper set but you can only buy them as a set (spring + damper). The downside to this is, what happens of you need a replacement damper? AC Schnitzer seems to make it impossible to buy the dampers individually. That being said, the ACS springs alone would be a noticeable improvement but if you're on Bimmerpost I doubt you'll be able to help yourself from modding the car further. Given that Christmas is not far off, the likelihood is even higher.

[JackG]

Thank you Watsey and casualDIYer for the responses!

I did consider a more complete suspension setup with dampers and springs. However, as mentioned prior I am a little reluctant due to the thievery that the insurance companies will commit.

That's one of the main reasons I decided to look at the ACS springs as they don't impact my insurance too much.

I will contact Lorcan to get some answers to my other questions.

Thanks!

[Lorcan]

Originally Posted by casualDIYer

As for the ACS springs, they are very good. AC Schnitzer does sell a matching damper set but you can only buy them as a set (spring + damper). The downside to this is, what happens of you need a replacement damper? AC Schnitzer seems to make it impossible to buy the dampers individually. That being said, the ACS springs alone would be a noticeable improvement but if you're on Bimmerpost I doubt you'll be able to help yourself from modding the car further. Given that Christmas is not far off, the likelihood is even higher.

We've always listed the dampers (as a kit) separately, for people that already have the springs. However, AC Schnitzer sports dampers for xDrive are now discontinued, so only RWD dampers are currently listed:

https://shop.rossiters.co.uk/ac-schn...rom-8106-p.asp

Individual replacement dampers are available, just not listed on our shop as I can't be arsed

And when they are gone, we can get existing ACS dampers rebuilt by Bilstein, as long as you're not in a hurry (which inevitably you will be, but at least we're not abandoning you completely).