Upgrading to Bilstein B12 + rebushing - ARB upgrade worthwhile?

Newbers · Post by **Newbers** » Thu Mar 30, 2017 12:21 am

Question to those that have fiddled about with their suspension - bearing in mind that whilst I don't track my Coupe, I do drive very 'briskly'.

At 68k miles its on the original suspension (except springs of course!) It is definitely a lot softer and less confidence inspiring in hard/fast corners now than it used to be so I'd liken to tighten that up. It is a daily driver and I live in Hertfordshire where they don't bother to repair the roads...

I'm planning to upgrade to a Bilstein B12 kit shortly. Whilst at it I'll do a few other bits:

I know the bushes at the rear of the wish bones are tired and I have Mehle HD replacements here ready.
The front ARB bushes look knackered so I'll swap them for Powerflex replacements.
The front strut top mounts knock so I'll do them too. (I guess this is an OEM part?)
I'll have a quick look at the other obvious bits before I order anything.

My car originally didn't have sport suspension so I believe it has the 24mm front ARB. Would I be likely to notice an upgrade to a stiffer one? (I don't really want to fork out for the H&R or Eibach 27mm ones but I know the M-Sport suspension came with a 25mm front ARB). I presume I'd have to change the rear too.

Should I think about a strut brace? I'm not really into anything boy racerish for the sake of it but some seem to report an improvement and also there are quite a few stories about damage to the strut towers which these would appear to help with.

Anything else obvious that I'm missing (while I'm down there....)?

Steve84N · Post by **Steve84N** » Thu Mar 30, 2017 8:26 am

Do it all and go for the H&R ARBs as the M Sport one isn't worth it.

Limiters on Meyle HD RTABs in the rear is another thing you could do.

Go for Lemforder front top mounts, same as what's there now.

Strut brace I've got a Weicher one, although it says 3.2 it fits the 3.0 fine and I bought that version as it bends around where the oil filler is rather than going over it. Can definitely feel an improvement in steering control and feel. http://www.wiechers-sport.de/en/shop/do ... ben-detail

aquarianone · Post by **aquarianone** » Thu Mar 30, 2017 10:01 am

I've actually just had my B12 kit fitted earlier this week and while it's only been a few day, it's def been worth it so far.

Mine is a 3.0si Coupe on around 82K.

I upgraded -

Lower control arms and bushes with the Meyle set from Ebay (around £210)
Meyle HD mounts for the rears (£12)
Lemfoder for the fronts (approx £40)
B12 Kit £675

It's early days but i'm def liking it, it hasn't dropped as much as I expected, which may not be a bad thing

it might settle a bit as I put the miles on - but from what i've read recently the new shocks will raise it up (back to std height I guess, versus tired suspension), so if you're looking for more slam...maybe go with Koni and H&R springs or coilovers.

That being said, it def feels much more tighter on turn in, more stable, less jittery...still firm..but it doesn't bounce you around..and is much more planted at speed.

So far so good and i'm trying no to think about going to 19's

(must resist!)

Next up, a trip oop north this w'end for the forums fabled exhaust mod

Newbers · Post by **Newbers** » Thu Mar 30, 2017 11:38 am

Thanks guys
aquarianone: I'm on the same page. I'm a bit 'mature' and practical for that slammed to the floor look. I replaced the standard springs with OEM sports springs when they broke. If the B12's end up similar or <> 10mm lower I will be happy.

Steve84N: Sounds great. You're a couple of steps ahead of me. I suppose it makes sense to commit to the ARB's from the outset and save myself £40 on Powerflex bushes (for the front). That said I didn't really want to commit more than a day to this. I'm guessing B12's + a couple of bushes (+ CDV which I haven't done yet

is going to take the best part of a day. I think I read the rear ARB is a bit of a pain and perhaps not one to start at 5pm Sunday afternoon?

On that basis I think I'll do: B12s + mounts, lower control arm bushes, strut brace, ARB bushes & CDV. Drive it for a bit and pay attention to handling characteristics.
Then phase 2: Limiters on Meyle HD RTABs + anything else that looks obviously tired back there.
Than phase 3: Upgrade ARB's.

Hopefully I can time this to when the wife is in Paris for the weekend and get the hall painted so she doesn't know what I've been doing....

Steve84N · Post by **Steve84N** » Thu Mar 30, 2017 12:22 pm

I also used Meyle HD rear top mounts after initially fitting Turner Motorsport ones that were a bag of bones.

adam1985 · Post by **adam1985** » Thu Mar 30, 2017 12:57 pm

If your changing anti roll bars and not just the bushes then might as well get new drop links front and rear as well for the small cost.
I used the meyle HD rear mounts when first changing to the B12 kit but got some knocking from the rear. I changed to the powerflex rear mounts and it went away but they are quite a bit more expensive. I also went with powerflex RTAB instead of the Meyle limiting type

Newbers · Post by **Newbers** » Fri Mar 31, 2017 11:24 am

I've been looking in to the RTAB limiters a bit more - amazing how much chat there is on the the internet and also how many options there are. I'm guessing it's probably worth doing these while the springs and shocks are out so I'll do that. The US companies all want a hefty fee for shipping. Unless anyone knows better I think I'll get the Condor Speed Shop RTAB Limiter Kit from Hack Eng. http://www.hackengineering.co.uk/produc ... 6-inc-m3/ I think £50 is my limit for four washers (even if they are precision engineered...)

BTW is there a consistently competitive supplier of the Lemforder / Meyle HD bits and pieces of is it a question of ringing/surfing around? I quite often get stuff from Euro Car Parts when they offer me 56% off but they don't list all these bits.

Steve84N · Post by **Steve84N** » Fri Mar 31, 2017 12:52 pm

Go on eBay for the mounts and also limiters. Search for 'psb Z4 bush limiters' as they're £18.85 delivered. It's not a complex part so will be fine.

Newbers · Post by **Newbers** » Fri Mar 31, 2017 7:36 pm

Purchased! Thanks great tip. I am happier with poly over aluminium (like Turner) for this application. Seems like a more appropriate combination of materials given the contact/repeated loading.

Killiestu · Post by **Killiestu** » Fri Apr 14, 2017 8:38 pm

Steve84N wrote: ↑Fri Mar 31, 2017 12:52 pm Go on eBay for the mounts and also limiters. Search for 'psb Z4 bush limiters' as they're £18.85 delivered. It's not a complex part so will be fine.

Hi Steve, those bush limiters your talking about , I can only find them for the 3 series not the z unless there the same part?

Cheers
Stuart

Worcester_spoon · Post by **Worcester_spoon** » Fri Apr 14, 2017 8:44 pm

M3 front arb fits - can pick one up on eBay. Either coupe of convertible one is a bit thicker (can't remember which) so do some research.

I also fitted Turner RTAB limiters - defo a hotly debated mod, but I'd say it's the best mod I've done for car feel. Well worth it.

Killiestu · Post by **Killiestu** » Fri Apr 14, 2017 8:48 pm

I like the idea of small improvements over standard as "large improvements " usually come at a cost of comfort!

So the B12 kit along with the other things sounds great, mine is the 3.0si coupe "56" and I'm not doing big miles but I am doing the odd trackday locally at knockhill so I was also thinking about a strut brace if you could recommend a good quality 1 that fits without to much hassle

Steve84N · Post by **Steve84N** » Fri Apr 14, 2017 9:37 pm

It's the same as the e46 for the RTABs.

I also have a 56 3.0si Coupe and have already linked my strut brace above...

Z4-forum.com

Z4-forum.com