Difference between M suspension and non-M

[Jstic]

Has anyone owned or driven a Z4 with the "m" sport suspension, and one without? What is the difference? Common sense tells me that the M suspension is lower and rides more firmly, is this correct? Are the shocks/struts the only difference betwen the two? I am not talking about just the M cars, as my Z4 3.0i lists the "M sports suspension" as included with the original car.Thanks in advance for any help with this.

[papitosabe]

IIRC the sports suspension is standard in the M, and an option in the SI's.

[jra]

Struts, shocks, lowering springs for sure...maybe sway bars?

[Incompatible]

Posted by The Hack many moons ago to a M vs non-M question (good background info). Springs, dampeners, ride height are the primary differences between the standard and sport non-M cars. And of course the "Sport" button.

"...Z4 non-M sports suspension is based on the E46 non-M design. Struts, springs, shocks, control arms...etc are all interchangeable between them. The Z4 M suspension is a hybrid between E36 M3 and E46 M3, with the front suspension parts being re-designed E36 M3 parts, and the rear suspension parts being redesigned E46 M3 parts. The swaybars are from E46 M3 as well (rears are E46 M3 CSL bars).

As for comparison, the non-M Z4 will hold its own, but the MZ4s have stiffer springs and higher damper rates, plus the MZ4s have more camber up front. The lower control arm is from the E46 330i with Performance Package (ZHP). The major difference will be the fact that the MZ4 has a tuned limited slip differential while the Z4 3.0Si has an open diff, and the M has servotronic rack-and-pinion steering instead of the non-M's electronically assisted rack-and-pinion steering. The M also has a quicker steering ratio.

End result, is that on the track the M has a much higher threshold, with quicker turn-in feel. But you will not be disappointed with the 3.0Si coupe, it'll likely hang at most tracks with the best of them. 265HP on a 2,9xx lbs frame is going to make a very capable car on track."

[Huz-Z]

In addition to the above, I think if you just look at a Z4M and a sprt-equipped Z4 SI, you will see that the SI seems to sit a bit lower to the ground than the M.

[psygnosis]

I've read that the pre-facelift Z4 with the sport suspension was lower then the M, but I didn't know that was still the case for 2006+ cars.

[intoflatlines]

Originally Posted by Huz-Z

In addition to the above, I think if you just look at a Z4M and a sprt-equipped Z4 SI, you will see that the SI seems to sit a bit lower to the ground than the M.

Maybe partially due to the bigger tires on the M?

[imom]

Jstic, if you look at my other post about SI to MR to BRZ, you can see I say go with the SI with M package vs a M for non track driving. True the M is better and stiffer, but for daily driving I preferred the SI with M sport package. You notice a difference between M and SI, but it's not night and day difference...more like M is 20% better, not worth all the baggage the S54 motor requires with maintenance...not a put down for M, just that the SI is a pretty good value... The coupe is really unique looking and I highly recommend the strut bar for either car...on the M it was a nice improvement stiffening the front end during turns was worth the $300 bucks.

[Huz-Z]

Originally Posted by intoflatlines

Maybe partially due to the bigger tires on the M?

Could be!