Not happy with my ///M ride....solutions..??

That makes perfect sense, I was under the impression H&R made a 27mm specific ARB for the Z4 and the m3 one was 30mm but it also fits the z4.

My thoughts were that with it being adjustable even at 27mm it could be marginally stiffer by decreasing the leverage point.

I was just basing this on this website however so could be completely incorrect

ee258ca2ad585a577a751c373e775452_zps3dc3807d.jpg
 
I should've specifically pointed out that I was referring to the H&R ARBs for the E46 M3, which I've found is a direct swap for the Z4M ARBs provided that you put a shim under the front brackets to give slightly better clearance of the chassis as well as to reinforce the mounting points.
 
meditek said:
Dammit another of these threads where the original poster disappears into the boondocks so we never find out the result.

Sorry to disappoint you but I m actually still here and I ain't done nothing yet...as and when I do you'll be the first to know

:)
 
I guess what would be handy to know would be how much stiffer the H&R 27mm ARBs are on the shortest setting...
 
exdos, ruling out the difference between your m and my non-m, have you experimented with larger/stiffer rear ARB's to neutralise a little of the understeer?

If so, cost/benefit deemed worth it?
 
NeilP said:
exdos, ruling out the difference between your m and my non-m, have you experimented with larger/stiffer rear ARB's to neutralise a little of the understeer?

If so, cost/benefit deemed worth it?

IMO the best way of reducing/removing perceived understeer is with the geometry. Zero front toe will help considerably. That's where I'd start. :thumbsup:
 
Suspension changes are quite critical to the behaviour of the car as I found out to my cost in my last Z,,,some of you will know all about that,,,I certainly will not be fitting any trailing arm limiters or polly bushes that dial out any flex in the chassis,,,this is not conducive to good road manners...ok on a silky smooth track though... :wink:
 
exdos said:
NeilP said:
exdos, ruling out the difference between your m and my non-m, have you experimented with larger/stiffer rear ARB's to neutralise a little of the understeer?

If so, cost/benefit deemed worth it?

IMO the best way of reducing/removing perceived understeer is with the geometry. Zero front toe will help considerably. That's where I'd start. :thumbsup:

Spot on, I now run marginal toe out on the front but for a DD I would suggest zero toe.
 
I too have pulled the plunge and ordered kw v3s after reading all the info supplied by exdos. Thank you for providing so much information on the matter. My car is a DD and I just can't live with the bumpy ride on the bad roads we have In Malta.

Is there anything else I need to update whilst installing the new suspension?
Exdos I tried looking up your alignment settings and from what I gathered you are running 0 toe front and back, -1.3 camber front and -1.0 camber rear. Can you confirm these settings and are they adaptable for daily driving?

Dondp, since the kws have so many settings can you maybe suggest where I should start from.

Thanks

Kerstien
 
DONDP said:
exdos said:
DONDP said:
I guess what would be handy to know would be how much stiffer the H&R 27mm ARBs are on the shortest setting...

I'll do a calculation tomorrow. :thumbsup:

Excellent, thank you. :thumbsup:

I've now measured the relevant dimensions of the Z4M's OEM front ARB , which is 27mm diameter. If the drop links were attached to the ARB arms making the lever length 0.75" shorter, this would effectively make the ARB 18.2% stiffer. In comparison, as I've previously said, fitting a 30mm ARB and using the same lever length makes the ARB 52.4% stiffer. But, if the lever length of a 30mm ARB is also shortened by 0.75" (as is possible with the E46 M3 H&R ARBs), then this would effectively make the ARB 80% stiffer than the 27mm Z4M OEM ARB.
 
kerstien said:
I too have pulled the plunge and ordered kw v3s after reading all the info supplied by exdos. Thank you for providing so much information on the matter. My car is a DD and I just can't live with the bumpy ride on the bad roads we have In Malta.

Is there anything else I need to update whilst installing the new suspension?
Exdos I tried looking up your alignment settings and from what I gathered you are running 0 toe front and back, -1.3 camber front and -1.0 camber rear. Can you confirm these settings and are they adaptable for daily driving?

Dondp, since the kws have so many settings can you maybe suggest where I should start from.

Thanks

Kerstien

I would recommend that you either fit Rogue rear top mounts or fabricate your own rear top mounts (as I've previously described elsewhere) that are inverted, so that you can remove/install the dampers from the underside in the wheel arch.

You've correctly listed my geometry and that's what I run on both public roads and at The Ring. With my suspension this works great.

With regard to initially setting up your KWV3s (essentially the same as my AC Schnitzer Racing suspension), if your use is primarily for a DD and road use, I would set the front up at quarter of the range from full soft and the rear at full soft and then progressively increase the settings until you feel that the suspension becomes too stiff at either end of the car, and then back-off that end by one adjustment. You will find that the rear suspension settings essentially determines your perception of the ride of the car and softish settings are best on the roads. At the front, you will find you can go stiffer than at the rear, and the front will feel too stiff when too much of the bumpiness of the road is being transmitted to the steering wheel; when you get to that stage, back off the front settings by one adjustment. Once you feel that the car is both comfortable and handles well, drive the car for a while so that you can experience the car on as many different roads surfaces as possible, and then you can decide if it's necessary to fine tune the settings. I have KWV3 on my Z3MC, but this variant has separate rebound and bump/compression adjustment: for road use I have the front at 50% from full soft and the rear at around 20% from full soft, but on track I have both the front and rear at around 90-95% from full soft. You don't want to be a "hero"with stiff suspension settings on public roads, because your car will handle badly and the ride will be dreadful.
 
exdos said:
NeilP said:
exdos, ruling out the difference between your m and my non-m, have you experimented with larger/stiffer rear ARB's to neutralise a little of the understeer?

If so, cost/benefit deemed worth it?

IMO the best way of reducing/removing perceived understeer is with the geometry. Zero front toe will help considerably. That's where I'd start. :thumbsup:

The second best way is better front tyres! I found an incremental reduction in understeer with the various mods I made to my suspension. However, the single biggest improvement came from ditching the OEM Contis in favour of PS2s
 
Has anybody tried the Tein S tech springs? It lowers the car less than the Eibachs and H&R which might give better ride comfort over bumps. I am not happy with the ride either even after changing to non run flat tyres and I have stock springs.
 
BMWZ4MC said:
The second best way is better front tyres! I found an incremental reduction in understeer with the various mods I made to my suspension. However, the single biggest improvement came from ditching the OEM Contis in favour of PS2s

I'm still on the OEM Contis and thought they performed admirably at The Ring. I'm in for a big treat when I eventually ditch them :D 8)
 
BMWZ4MC said:
The second best way is better front tyres! I found an incremental reduction in understeer with the various mods I made to my suspension. However, the single biggest improvement came from ditching the OEM Contis in favour of PS2s
Did you really mean PS2, or was that a typo and you meant the PSS?
 
I meant PS2 - I haven't tried PSS yet as they weren't available when I last changed the tyres on my track wheels. I haven't chewed through as many sets of tyres as normal in the last year as the car has been stationary most of the time since February :D

exdos said:
I'm still on the OEM Contis and thought they performed admirably at The Ring. I'm in for a big treat when I eventually ditch them :D 8)

Yep! Although I like having OEM Contis on the back as it makes the rear of the car more lively under power :D
 
exdos said:
BMWZ4MC said:
I already have a front strut brace, and I'm considering one for the rear too.

I have a rear "butt-strut" on my Z3MC but I'm not convinced that the Z4MC needs one because it's not the same semi-trailing arm suspension design.The RTAB limiter kit should effectively do the same or similar job.

Thanks, I'll bear that in mind. I've lots of suspension bits to fit and fiddle with when I get home anyway :)
Is your "butt-strut" in the boot between the shock towers or under the car? I've seen something for the Z4 that goes beneath the vehicle but the description of its benefits wasn't wholly convincing...
 
DONDP said:
BMWZ4MC said:
And another:

KW Clubsports with camber / castor plates
RTAB limiter kit
Rogue rear top mounts
Front and rear ARBs (plus shims as per Exdos)

all waiting to be fitted.

I already have CSLs and a front strut brace, and I'm considering one for the rear too. I'll change the engine mounts when I fit a supercharger next year.

Nice! What ARBs did you go for?

H&R E46 M3 ARBs front and rear (after discussion with Exdos :D )
 
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