Z4M Suspension/tyre question

[drummachine]

I fitted a set of CSL's back end of the year and although i have only done a handful of trips in it, its noticeably harder. A lot harder!

The wheels came with Michelin Pilot Sport Cup tyres and i think this may be part of the problem? They seem rock hard as i know they are more of a track tyre. I have fitted many 18" > 19" before and its never made this much difference.

Before it fitted the CSL's i seriously considered fitting some H&R springs as well so my question is this...

Has anyone any experience of the cup tyres and is the hard ride mainly due to these tyres? Do 19" CSL' normally make a dramatic difference in ride?

Do H&R springs affect the ride much in general? My preferred option would be H&R springs with new tyres all round.

[mmm-five]

Within a year of buying mine, I'd swapped from 19" genuine CSLs to OE 224M 18" wheels & tyres.

Not ever wanted to go back - although the Bilstein PSS10 suspension might negate some of the crashy/skippy ride I had on them! I can't blame the original suspension too much as it was only 2 years / 20,000 miles old.

Clean CSLs @ 9am


Dirty CSLs @ 3pm

[dgm]

I’ve happily run mine on CSLs for over 10 years, I remember them giving a slightly harsher ride than the 18s when I changed them but nothing that bothered me. I also ran a second set of CSLs with Michelin Cups on them for a couple of years and don’t remember them being much harsher than the PS2s I was then using.

What I would say is that the PS4S is a softer tyre than the any of it’s equivalent Michelin predecessors, they’re quite a bit more forgiving in the ride department.

[Jembo]

You mainly have two tyre choices.

On the rears it’ll be 265 x 30 x 19 or 255 x 35 x 19 where obviously the 265’s will give a harder ride

What are you running?

[R60BBA]

If you decide to put lowering springs such as H&Rs on your Z4M with Sport Cups, you are effectively putting more stress on your suspension components, which will make your tyres work harder. In other words, your ride comfort will become even more compromised and your tyres won’t last very long.

This is the way I see it:

1. Keep the CSLs but replace the Sport Cup tyres with the Pilot Sport 4S (softer sidewall thus will provide more comfort and better grip all year round [Sport Cups and Cup 2s are for summer or track, not autumn or winter]).

2. Replace the CSLs with a lightweight 18” wheel (e.g. Apex Arc-8), as this should provide much more comfort, plus better handling. Again my tyre of choice would be the Pilot Sport 4 in an 18” set up.

In regards to lowering the car, I’d recommend a proper coilover set up (such as Bilstein PSS10 or KW V2s) which have been corner balanced, as opposed to lowering springs on 10+ year old OE dampers.

Good luck and let us know how you get on.

[drummachine]

Thanks for the responses guys.

Currently running 265/30/19 which certainly wont help.

I've almost convinced myself that i need to replace the tyres regardless and i will then sell the Cup's on here as they haven't been used much and i certainly wont get the chance to.

[Argenta]

I'm running 265/35-19 at the rear (which are closer to OEM rear diameter) and I manage very well.
(No they don't scrape the arches)
However I also run Eibach Pro springs which are ace value.

[RedUn]

Thanks for the responses guys.

Currently running 265/30/19 which certainly wont help.

I've almost convinced myself that i need to replace the tyres regardless and i will then sell the Cup's on here as they haven't been used much and i certainly wont get the chance to.

Sounds like a plan, eibach springs would be my choice with the standard dampers, the ride is very reasonable!

I "think" the h&rs are slightly firmer from reading on here, easy enough to get the spring weights off the two sites though.

[bradz]

Cups have considerably harder sidewalls as they are a track orientated tyre.

Cup2's are slightly better, What ones do you have? Check the date on the tyres too.

If you switch to Pilot sport 4's you'll get a softer ride.