Skittish going over rumble strips

[kimiraikkonen]

Had a previous E90 M3, 2008 model, 120K+ miles w/ 18" OEM 219M wheels and EDC suspension. Car always felt very planted on road transitions and never felt any loss of traction when going over Botts' dots or rumble strips on the road.

Fast forward to my new car, which ironically, is also an E90 M3, 2008 model, with 103K miles and EDC suspension. Only difference is this car has the 19" OEM 220M wheels.

The issue I feel now is that when driving over Botts dots or rumble strips, I feel a bit more skittish on the rear end. So not sure if it's the greater unsprung weight from the 19" wheels or if it's something else..........the car just doesn't seem as planted as my previous E90 M3. Could be worn suspension but seeing as my previous M3 had similar mileage, am thinking the difference is the heavier 19" wheels and less sidewall?

[SAMM3Y]

Rear toe? Get an alignment maybe or shot dampers.... I believe recommended service interval on dampers is 80k

[dparm]

Originally Posted by SAMM3Y

Rear toe? Get an alignment maybe or shot dampers.... I believe recommended service interval on dampers is 80k

There is no service interval for dampers, AFAIK. You replace them when they're worn.

I agree that I would check the alignment, but the car is going to behave differently due to the larger wheels and smaller sidewalls. Heck, it could just be a difference in the tire design or compound. Unless you are having huge problems with the car wanting to rotate (DSC intervening) over bumps, I wouldn't really worry about it.

[SAMM3Y]

I read 80k somewhere but have seen 50-60k several places too...

Turner say 50-60k but of course they want to sell them to you, all depends on the hard life the struts have led. Mine were shot at 70k but had lived a hard life on eibach lowering springs and sweet Bay Area third world highways if your original struts have 100k on them I'd definitely start thinking about a suspension refresh.

https://www.turnermotorsport.com/BMW...-shocks-struts

[kimiraikkonen]

Originally Posted by SAMM3Y

Rear toe? Get an alignment maybe or shot dampers.... I believe recommended service interval on dampers is 80k

I've tried driving with the EDC on Sport setting (2 lights) and it feels a bit better. So yes, probably the dampers going off, but think things are being exacerbated a bit by the heavier OEM 19" wheels (vs. 18" 219M).

[kimiraikkonen]

Originally Posted by kimiraikkonen

I've tried driving with the EDC on Sport setting (2 lights) and it feels a bit better. So yes, probably the dampers going off, but think things are being exacerbated a bit by the heavier OEM 19" wheels (vs. 18" 219M).

One thing I noticed is that I'm still running the original ECU SW, integration level E89X-08-03-530.

Will be upgrading the SW in the future of course...but wanted to know if anyone is aware of any changes to the Traction Control/DSC sensitivity in the later ECU updates?