[HighlandPete]

A thought...

Has anyone actually asked BMW Technical Department (not BMW UK CS) the question... can an alternative lowered spring be fitted to xDrive?

The answer may be no, but there may be some reasoned answers given.

HighlandPete

[Tengocity]

Originally Posted by Waitey

I won't lower an adaptive system on an X drive, without fitting the adaptive dampers from a S drive.

Any evidence as to why this would make a difference? I can see why that might be an option, but what if the xdrive damper has other characteristics which are more relevant to the car than the sdrive ones, outside just the ride height?

[Waitey]

Originally Posted by Tengocity

Any evidence as to why this would make a difference? I can see why that might be an option, but what if the xdrive damper has other characteristics which are more relevant to the car than the sdrive ones, outside just the ride height?

I was just speaking as per the ride height side of things.

An X drive Adaptive with lowering spring would be out of range.

An S drive wouldn't be as far out.

* Assuming S drive = 15mm lower than X drive.

[Tengocity]

Originally Posted by Waitey

I was just speaking as per the ride height side of things.

An X drive Adaptive with lowering spring would be out of range.

An S drive wouldn't be as far out.

* Assuming S drive = 15mm lower than X drive.

I'm no expert on damper units, but wouldn't the rate of damping not be consistent throughout the range, on any damper? And if so then as long as you are in the working range of the damper it shouldn't have any effect...

I can see how a spring could be made progressive, but even on adjustable dampers you are adjust the rebound and/or compression, but that would still be a fixed rate throughout the working range surely?

[Waitey]

Originally Posted by Tengocity

I'm no expert on damper units, but wouldn't the rate of damping not be consistent throughout the range, on any damper? And if so then as long as you are in the working range of the damper it shouldn't have any effect...

I can see how a spring could be made progressive, but even on adjustable dampers you are adjust the rebound and/or compression, but that would still be a fixed rate throughout the working range surely?

Damping rates should be constant but its hard to get a perfectly efficient system.

Move them out side of their designed range and you open up lots of random problems, even such things like heat evacuation start to be an issue.

[Tengocity]

Originally Posted by Waitey

Damping rates should be constant but its hard to get a perfectly efficient system.

Move them out side of their designed range and you open up lots of random problems, even such things like heat evacuation start to be an issue.

So I guess this is why a proper coilover set can be so expensive?

[Waitey]

Originally Posted by Tengocity

So I guess this is why a proper coilover set can be so expensive?

Especially when you move into the world of remote reservoirs etc.

[dopper99]

Originally Posted by HighlandPete

A thought...

Has anyone actually asked BMW Technical Department (not BMW UK CS) the question... can an alternative lowered spring be fitted to xDrive?

The answer may be no, but there may be some reasoned answers given.

HighlandPete

I’m not sure how you contact the BMW technical department but I emailed the question to BMW before I got my car. I was told to contact my local dealership for information on this as I was told they are “fully trained in all technical aspects of BMWs”. I never bothered contacting them as they probably wouldn’t have a clue.

[Happy Williams]

Hi guys, whilst I do really appreciate all the constructive and technical feedback, the way I see it is a bit more simple. It's my car I own and I'll do with it what I want, I'll take advice from people I trust and give it a go, if it doesn't work out I must accept the problem and deal with it, change it back, keep it whatever?! I believe from my non technical, simple minded view it will run and corner as good as it does now which will be fine for me!

I've been into birds bmw today and explained what I'm after and Kevin knew exactly what he was talking about and we compared my car to several other models he has and it really does sit to high, looking to drop around 30mm front and 25mm approx rear.

I'm just waiting for him to get back to me with a firm solution which he believes he has sorted then get booked in!

I'll keep you all posted!!

Dan.

[Tengocity]

Originally Posted by Happy Williams

Hi guys, whilst I do really appreciate all the constructive and technical feedback, the way I see it is a bit more simple. It's my car I own and I'll do with it what I want, I'll take advice from people I trust and give it a go, if it doesn't work out I must accept the problem and deal with it, change it back, keep it whatever?! I believe from my non technical, simple minded view it will run and corner as good as it does now which will be fine for me!

I've been into birds bmw today and explained what I'm after and Kevin knew exactly what he was talking about and we compared my car to several other models he has and it really does sit to high, looking to drop around 30mm front and 25mm approx rear.

I'm just waiting for him to get back to me with a firm solution which he believes he has sorted then get booked in!

I'll keep you all posted!!

Dan.

I like the attitude Dan! I can see why you're happy!

[Happy Williams]

Don't worry be happy now!!!

[Happy Williams]

Originally Posted by Tengocity

I like the attitude Dan! I can see why you're happy!

Hi all, just to keep you posted. Ok the solution is sorted, drop the car 20mm on eibach springs, spring rate, ride etc is maintained - there is a restriction on the suspension that is way to complex for me to understand is 20mm enough, a question for me?

Solution 2 is to use a much harder h&r spring, will drop 40mm, probably too much anyway but ride quality will be severe and probably hit the stops.


Anyway there you go. 645+vat. Now it's make up my mind time!!


Dan.

[MarkG_M5Comp]

Originally Posted by Happy Williams

Hi all, just to keep you posted. Ok the solution is sorted, drop the car 20mm on eibach springs, spring rate, ride etc is maintained - there is a restriction on the suspension that is way to complex for me to understand is 20mm enough, a question for me?

Solution 2 is to use a much harder h&r spring, will drop 40mm, probably too much anyway but ride quality will be severe and probably hit the stops.


Anyway there you go. 645+vat. Now it's make up my mind time!!


Dan.

Details and pics please!! (you know you'll do it). 20mm is just fine considering everything else stays the same.

[dopper99]

Yep, fair play to you Dan for pioneering this (in the UK anyway). Will be interesting to see what you go for and how it looks.

You know you'll have LOTS of envious xdrive owners drooling at them pics....

[Tengocity]

Originally Posted by Happy Williams

Hi all, just to keep you posted. Ok the solution is sorted, drop the car 20mm on eibach springs, spring rate, ride etc is maintained - there is a restriction on the suspension that is way to complex for me to understand is 20mm enough, a question for me?

Solution 2 is to use a much harder h&r spring, will drop 40mm, probably too much anyway but ride quality will be severe and probably hit the stops.


Anyway there you go. 645+vat. Now it's make up my mind time!!


Dan.

2 cm sounds good to me.. just enough to make a difference visually. Any idea if they will be much stiffer than the stock ones?

[Dave_3]

Originally Posted by Happy Williams

there is a restriction on the suspension that is way to complex for me to understand.....

Where did this explanation come from, any chance you could tell us what you were told ?

D.

[Happy Williams]

Originally Posted by Dave_3

Where did this explanation come from, any chance you could tell us what you were told ?

D.

Something to do with the length of the strut and a standardised design across the range which gives the height limits on all the F30,s, even the sdrive are noticeably higher. This is the best you can do without either going into major modification work or using a harder spring which will effect ride quality. I.e h&r 40mm.

Hope that helps a little.

[Happy Williams]

Originally Posted by Tengocity

2 cm sounds good to me.. just enough to make a difference visually. Any idea if they will be much stiffer than the stock ones?

Hi, I'm being told that the ride will be very similar to stock, but there will be a little less body role, that's good with me!!

[Cootie]

20mm sounds good to me - a little lower than an M-sport s-drive, which actually keeps it quite discreet, whilst maintaining the ride quality. If it reduces body roll as well then it would get my vote

[dopper99]

Originally Posted by Happy Williams

Hi, I'm being told that the ride will be very similar to stock, but there will be a little less body role, that's good with me!!

Are you going to change the ARB to the one as fitted to the 330d? That will also improve body roll of course.

[Tengocity]

Originally Posted by dopper99

Are you going to change the ARB to the one as fitted to the 330d? That will also improve body roll of course.

It will save labour costs if all done at the same time too. The ARBs need the subframes dropped to be done, so not a simple job!

[Cootie]

Birds offer their own anti-roll bar kit - supposedly £865+vat fitted