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KW V3 coilovers

2003 - 2009, roadster, coupe, facelift
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gideon87
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KW V3 coilovers

Post by gideon87 » Wed Dec 13, 2017 2:43 pm

Im thinking about getting a new suspension for my car to get rid of the stock ones and i see KW is rated quite highly on this forum as being a good make. Im aware that there good for track races etc. but are they any good for daily commuting/driving i.e do they make the ride feel smoother rather than feeling every bump and pothole in the road like with the stock ones.

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GuidoK
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KW V3 coilovers

Post by GuidoK » Wed Dec 13, 2017 4:56 pm

KW V3 is much stiffer on bumps than stock (but indeed great for cornering etc).
Same goes for V2/V1.
I think part of that comes from the fact that KW uses a different spring type for their Z4 coilover; linear springs compared to the stock progressive springs.
So if you want a smooth ride, stay with stock or maybe look at coilovers with progressive springs (but a coilover system is usually a performance part, thus stiffer)
Z4 3.0i | ESS TS2+ | Quaife ATB LSD | Brembo/BMW performance BBK front/rear | Schrick FI cams | Schmiedmann headers+cats | fully polybushed | Vibra-technics engine mounts | H&R anti rollbars | KW V3 coilovers | Sachs Race Engineering clutch

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MrPT
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KW V3 coilovers

Post by MrPT » Wed Dec 13, 2017 8:54 pm

V3s have progressive springs. Downside is that they are conical so the fronts need a spacer to clear most wheels.

The ride is good, but more in terms of compliance/composure than comfort. I have no experience of a direct comparison but would imagine that the stock ride is “smoother”, in that minor bumps are flattened out, and it’s when driving aggressively on less-then-perfect surfaces that the V3s will significantly outperform the stock suspension.
2008 Z4MC: heavy wheels | crap suspension | skittish rear end | wobbly engine | not enough induction noise | underwhelming turn in | inconsistent braking | lardy battery | chubby steering wheel
2006 Z4 2.5si: gone

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GuidoK
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KW V3 coilovers

Post by GuidoK » Thu Dec 14, 2017 1:28 am

MrPT wrote: Wed Dec 13, 2017 8:54 pm V3s have progressive springs.
No they dont.
In fact, for the Z4 ALL KW coilovers sets come with linear springs on the front struts. You can look at the TüV gutachten to verify.


You're talking about the Z4M. On the Z4M you only get lineair springs on the front struts when you buy the clubsport ones.
But Z4M coilovers dont fit Z4's
Z4 3.0i | ESS TS2+ | Quaife ATB LSD | Brembo/BMW performance BBK front/rear | Schrick FI cams | Schmiedmann headers+cats | fully polybushed | Vibra-technics engine mounts | H&R anti rollbars | KW V3 coilovers | Sachs Race Engineering clutch

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MrPT
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KW V3 coilovers

Post by MrPT » Thu Dec 14, 2017 11:24 am

GuidoK wrote: Thu Dec 14, 2017 1:28 amYou're talking about the Z4M.
I am, yep, sorry. And E89.

Didn’t know the non-M V3 fronts had linear springs. Any idea why?
2008 Z4MC: heavy wheels | crap suspension | skittish rear end | wobbly engine | not enough induction noise | underwhelming turn in | inconsistent braking | lardy battery | chubby steering wheel
2006 Z4 2.5si: gone

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GuidoK
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KW V3 coilovers

Post by GuidoK » Thu Dec 14, 2017 3:04 pm

MrPT wrote: Thu Dec 14, 2017 11:24 am Didn’t know the non-M V3 fronts had linear springs. Any idea why?
I think it maybe has to do with the front of the z4m being heavier (cast iron block instead of aluminium block).
For the e46, you can have a choice of both linear and progressive springs in the front on all KW performance coilover sets.
If you choose the linear sets, you get the same stiffness as the z4 v3 springs, but on the e46 they are longer.
However if you choose the progressive spring on the e46, you get the same spring as the z4m spring on the lighter cars. I think this spring would be too long for the normal z4, but apparantly it fits on the z4m (makes sense if its compressed more due to more weight).

The z4 has a 65kg lower front axle load spec than the z4m.
And they maybe didnt feel to make a shorter or lighter bespoke progressive spring for the z4, so they fitted a linear spring, whereas for the z4m they had more choice out of the e46 parts bin.
Z4 3.0i | ESS TS2+ | Quaife ATB LSD | Brembo/BMW performance BBK front/rear | Schrick FI cams | Schmiedmann headers+cats | fully polybushed | Vibra-technics engine mounts | H&R anti rollbars | KW V3 coilovers | Sachs Race Engineering clutch

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