Your experiences of aftermarket suspension on the Z4 MC

[Beedub]

TBH, unless the suspension can be adjusted electronically from inside the car, then all adjustable suspension is a bit of a pain to adjust. A torch and a pair of plastic caravan ramps are useful at the track so that you can lift the car a little so that you can see what you're doing when making the adjustments at the bottom of the dampers see: http://www.ebay.co.uk/sch/i.html?_t...van+ramp&_nkw=caravan+ramp&_sacat=0&_from=R40

yeah i agree its all a royal pain in the ass..... i wish i could do it via the iphone like some setups allow!!

 

[BMWZ4MC]

I was planning to uprate the front ARB at the same time as fitting coilovers and then start thinking about the brakes!

The best price I had for Clubsports when I was looking last year, was £2.3k including camber/caster plates.

Since you are trying to make a highly focussed track car, you should definitely fit the caster/camber plates, but instead of increasing negative camber, I would suggest that you should increase caster, because this gives an increase in negative camber in the dynamic situation when the steering is turned and better straight line stability and self-centring. To see a demonstration of caster in operation, just watch the movement of the front wheels of any modern Mercedes saloon when it is parking, and you'll observe the considerable change in camber created by turning the steering.

Uprating the front ARB, only, might be the answer with the very soft OEM front springs, but If you're going to redress the gross imbalance of the OEM spring rates with those of KW Clubsports, if you uprate the front ARB, you should also uprate the rear ARB too, to preserve the suspension balance that you'l have with the Clubsports.

Thanks for the advice John, your wisdom is always welcome Do you think polybushes would be a good idea at this stage too?
Can you remind me, what did you use when you uprated the front ARB on your Z4M? I think you said you modified something intended for the E46 M3...

 

[exdos]

Thanks for the advice John, your wisdom is always welcome Do you think polybushes would be a good idea at this stage too?
Can you remind me, what did you use when you uprated the front ARB on your Z4M? I think you said you modified something intended for the E46 M3...

Richard, you'll be pleased to know it's probably as hot here at present as it is where you are

Here's a link to my bit about fitting the front ARBs: http://www.z4-forum.com/forum/viewtopic.php?f=9&t=38918&hilit=ARB&start=90#p565636 I think you're referring to fitting some shims between the ARB brackets and the chassis. In the end, I fitted a pair which are about 6mm thick which work well. I'll make you a pair before you fit H&R ARBs.

Personally, I haven't felt any need to replace any of the OEM bushes except for fitting Turner Motorsport RTAB limiters, which effectively restricts the lateral movement of the trailing arms, thus preserving rear toe angles, and likewise, the Vibra-Technics Engine Mounts restricts horizontal movement of the engine. So, altogether with better spring balance and excellent damping (i.e. adjustable suspension) and reduced lateral bodyroll (H&R ARBs) the suspension and handling is transformed. You will be truly amazed at the difference! 8)

 

[BMWZ4MC]

Well, I've just ordered KW Clubsport coilovers as well as front and rear H&R ARBs. They should be delivered this week although I'll have to wait six months beofre I even see them. It might sound ridiculous having parts sitting around in boxes 12,000 miles away but, since I'm planning to buy a BBK before hopefully supercharging my ///M when I go home next year, I need to spread the cost over several months. I just can't bring myself to spend that much money in one go next February!

 

[exdos]

Well, I've just ordered KW Clubsport coilovers as well as front and rear H&R ARBs. They should be delivered this week although I'll have to wait six months beofre I even see them. It might sound ridiculous having parts sitting around in boxes 12,000 miles away but, since I'm planning to buy a BBK before hopefully supercharging my ///M when I go home next year, I need to spread the cost over several months. I just can't bring myself to spend that much money in one go next February!

You should've arranged to have them delivered to me along with your car. I could then have fitted it all for you, taken the car on a few trackdays, at your expense, and then it would all be ready for you as soon as you returned.

 

[BMWZ4MC]

Richard, you'll be pleased to know it's probably as hot here at present as it is where you are

Here's a link to my bit about fitting the front ARBs: http://www.z4-forum.com/forum/viewtopic.php?f=9&t=38918&hilit=ARB&start=90#p565636 I think you're referring to fitting some shims between the ARB brackets and the chassis. In the end, I fitted a pair which are about 6mm thick which work well. I'll make you a pair before you fit H&R ARBs.

Personally, I haven't felt any need to replace any of the OEM bushes except for fitting Turner Motorsport RTAB limiters, which effectively restricts the lateral movement of the trailing arms, thus preserving rear toe angles, and likewise, the Vibra-Technics Engine Mounts restricts horizontal movement of the engine. So, altogether with better spring balance and excellent damping (i.e. adjustable suspension) and reduced lateral bodyroll (H&R ARBs) the suspension and handling is transformed. You will be truly amazed at the difference! 8)

John, the weather in the UK sounds like it has been consistently hotter than for several years. I can't say I'm jealous as working in London is almost unbearable with temperatures so high.

Following the advice in your link, I've bought both front and rear ARBs, I just hope the rear will fit too as I don't think you have tried to fit yours yet I'd very much like to take up your kind offer of shims for the front when I come home - I'll send you my parents' new address nearer the time if that would be ok with you. Cheers

I think I'll buy the Vibra-Tech engine mounts when I come to fit a supercharger as I think the engine needs to be dropped (IIRC from Beedub's description) so it would be an ideal time to do this.

I'm looking forward to coming home now, I'm not sure how I am going to survive another six months of sunshine and having fun

 

[BMWZ4MC]

Well, I've just ordered KW Clubsport coilovers as well as front and rear H&R ARBs. They should be delivered this week although I'll have to wait six months beofre I even see them. It might sound ridiculous having parts sitting around in boxes 12,000 miles away but, since I'm planning to buy a BBK before hopefully supercharging my ///M when I go home next year, I need to spread the cost over several months. I just can't bring myself to spend that much money in one go next February!

You should've arranged to have them delivered to me along with your car. I could then have fitted it all for you, taken the car on a few trackdays, at your expense, and then it would all be ready for you as soon as you returned.

Well, if you don't mind buying and fitting AP brakes and a SC for me, the car's yours until Feb

 

[BMWZ4MC]

Cheers. So it looks like I can get Clubsports together with the adjustable top mounts from Larkspeed https://www.larkspeed.com/index.pl?p=L35220834&a=i for the same amount as the best price I'd seen elsewhere for the Clubsports alone. Does 2k sound reasonable to you Beedub? Or do you think I should keep shopping around?

thats a good price!!! they usually retail at 2500 with the top mounts... dont forget to order new rear top mounts.... i went with the R.E units.. fabulous pieces!!
At least at this point you can rebuild the dampers too.. 125 quid is expensive but much cheaper than new units....

Beedub, I haven't ordered rear top mounts as yet as I'm not sure of the diameter of the shocks with the Clubsport setup - the RE information describes 10mm washers for OEM and some aftermarket shocks, but states that some shocks need "optional 12mm washers". Do you remember which washers you used with your RE top mounts / clubsport setup? Cheers.

 

[exdos]

Following the advice in your link, I've bought both front and rear ARBs, I just hope the rear will fit too as I don't think you have tried to fit yours yet I'd very much like to take up your kind offer of shims for the front when I come home - I'll send you my parents' new address nearer the time if that would be ok with you. Cheers

I fitted the rear ARBs just a couple of weeks after fitting the front H&R ARB, because it didn't feel balanced without the rear being uprated. No problem fitting it at all.

Well, if you don't mind buying and fitting AP brakes and a SC for me, the car's yours until Feb

Not at all. Just give me your credit card details in a PM and consider it sorted.

 

[BMWZ4MC]

By all means, just so long as you set up a direct debit to pay off the credit card bill

 

[BMWZ4MC]

Following the advice in your link, I've bought both front and rear ARBs, I just hope the rear will fit too as I don't think you have tried to fit yours yet I'd very much like to take up your kind offer of shims for the front when I come home - I'll send you my parents' new address nearer the time if that would be ok with you. Cheers

I fitted the rear ARBs just a couple of weeks after fitting the front H&R ARB, because it didn't feel balanced without the rear being uprated. No problem fitting it at all.

Good to hear

 

[ChawenHalo]

The Bilstein PSS10's have very easy adjustment knobs i believe. Check out the pictures in this post: http://www.zpost.com/forums/showpost.php?p=11665817&postcount=1

Yep I can confirm they are dead easy to adjust:

Stopped the car with my girlfriend on the way to the beach the other day as she said the front was bouncier than before. Imagine her surprise as I got my arse on the ground, and my arm behind the front wheel, asked her to be quiet for for sec, felt for the knobby thing (carfull not to oput my paw on the hot brake disck), heard a couple of clicks, got back in the car and drove off. 5 cmins later she proclaimed it was better.

 

[ChawenHalo]

Following the advice in your link, I've bought both front and rear ARBs, I just hope the rear will fit too as I don't think you have tried to fit yours yet I'd very much like to take up your kind offer of shims for the front when I come home - I'll send you my parents' new address nearer the time if that would be ok with you. Cheers

I fitted the rear ARBs just a couple of weeks after fitting the front H&R ARB, because it didn't feel balanced without the rear being uprated. No problem fitting it at all.

Good to hear

No nopoise from either the front or rear H&R ARBs. They're a good fit.

 

[ChawenHalo]

Update on the Bilsteins/ Delage Sport set up aftyer a couple of track days

BIzzarely after a few months things seem to be softer on the road and I suspect its 2 things: A/ I'm getting used to it and B/ it needs a certain amount of time to settle in. its still 15% less comfy in town though and we have lots of paved roads over here . On the road, it really is brilliant. The steering has way more feel, and precision, the rear is far more planted and efficient even on roads where it would skip about. It still does but in a more controlled manner and you can put the power down. car is much more lively and direct though.

On track: One hot day and one cold and slightly wet days. Tyres heat up much faster and so had to let plenty of air out (0.8 bar for the rear 0.4 at a time! in over just two 20 mins sessions). The drive train is definitely working a lot harder as mates following in an Exige commented. Front end grip is improved with no understeer unless way above entry speed into a corner. Braking is much more stable as is of course acceleration. All in all its much more communicative and precise but what has really amazed me is just how adjustable it has become. On long sweeper it very stable and you can really trim you line between delicate throttle and steering inputs. Tight technical corners with a long opening after its always been an agile car, I enter with either trail braking or downshift to 2nd, steer it on the throttle and bang fast out of the corner. After this particular "parabolic corner there is a long straight with large hump and a blind decent after it with a slight turn and a bit of a straight to brake before a tight corner. I used to chicken on that hump and just get off the gas. Now I keep some gas on and brake way latter ( that's the mud when I cocked up the braking by 10 mph) I've got to say none is different to the OEM character of the car but its just less waving your arms about steering and countersteering. Last bit, the chassis just gives you way more confidence at the limit, even though it feels lively and "nervous" its smooth precise and progressive, its does try to kill you and that makes the whole difference when your pushing it and at times getting it wrong.

I rekon these changes suit the car. It has not altered its character and puts in more in the Sports direction than GT. It feels safe and competent.

Little pic:

 

[ga41]

Sounds like an overall great modification then! Will keep this in mind for the future.

 

[Vanne]

Anyone have any ride reports from fitting Bilstein HD shocks and H&R springs? Interested in your setup and ride quality. Also how hard was/traps while installing?

I guess I should edit this a little.

My car has coming up to 120k miles on it and in the last 6 months have refurbed the whole underside, including new rubbers everywhere, rebuilt the diff and carrier. Though still on stock struts and suspension.

As an early Chrissy pressie I ordered from turner motorsports a full set of Bilstein HD struts and picked up some z4m H&R 29119-1 springs. Kinda figured it was time as 120k miles is a bit for stock suspension. (Picked up the springs on quite a few recommendations from the guys on this forum

Now I also still have to install (already hoarded) new transmission mounts and engine mounts, (stock are still fine, but want to complete the full refurb and have some really nice mounts )and was wondering if it would be good to do it at the same time as the suspension or do one before the other?

I also have new rear shock mounts to go in and I also have the spacer for the rear springs in case the car slams too low..

So where would you guys start?

 

[Vanne]

kay, (update) i finally got around to getting my new shocks/struts/springs installed. went to my friends shop and did it on the lift. watched a guy do it pretty much as i would have done it, but was nice chatting to him while watching him do it all. it makes for a quite easy job if you have all the tools/equipment..


H&R 29119-1/Bilstein HD

All installed without a drama, and was quite pleased at the ride height. not too low, not too high, just right.

so now comes the question of alignment/setup.

(repeating here to keep it easy for people to find for this setup)

so at the moment i will be driving around for around 500 miles to bed in the suspension and then looking to get an alignment. currently looking at:

front negitive camber??
zero toe

rear -1.2 negative camber
zero-ish toe in/out

this will be a street setup, with the every so often track day thrown in. 7 mill spacers (i have 10 atm, but i think it sits out a little too far for my linking with my front tires) in the front and 3 mill spacers in the back. fronts 235/40/r18 rear 265/35/r18

so far ive driven about 150 miles and the setup is smooth as silk, and not alligned, and would love some more input on toe in/out and camber settings for the front. thx guys...

 

[abar121]

Vanne,
Many thanks for your feedback on the Bilstien HD kit.

How is the ride quality compared to stock?

Cheers, Alan.

 

[Vanne]

I can't really comment yet, still bedding the new springs in, about 350 miles to go and then a alignment. So until then, I can't say too much.

 

[ChawenHalo]

I can't really comment yet, still bedding the new springs in, about 350 miles to go and then a alignment. So until then, I can't say too much.

Nice! not sure how much you can change the geo without specific mounts and plates fella... I'd go to some racing outfit and get them to do a street set up (you got sandy roads out there?) :lol: