M sport spring breaking and absorber choices

O

owm

Member
 Malaysia & Singapore
Good day,

I have been reading up on the M sport spring snapping/breaking and would like to know if this is something that will eventually happen (just like the VANOS slowly failing if it has never been rebuilt with the upgraded seals) or there are owners out there who are still happily on these M sport springs without issue? Reason I am asking is the choice of aftermarket springs out there all seem to drop the car a fair bit and there are no published data on the spring rates. I am actually happy with the 15mm drop that the M sport spring provides and would prefer sticking to them (mine are still intact) or an equivalent set that gives roughly the same drop and spring rate.

For those who run the Koni sport absorbers on the M springs, how is the ride quality? Is the car poised and composed over rumble strips, pot holes, road imperfections etc.? My ori M sport Sachs are nearly the end of their usable lifespan (oil stains seen on the shock body) and am thus on the look out for a replacement set of 4.

It appears the Bilstein B6 (up to 30mm drop) can also handle the M sport spring (15mm drop) but would like to know how the Bilstein stacks up to the Koni. Funnily enough, there isn't much information when it comes to suspension compared to my MX-5.
 
There's a 45 page thread about broken springs... so that should give you an idea of spring break rates. I like to think of them as having a half-life!
Eibach provide spec sheets if you look on their catalogue and drop by about 15mm more than M-sport. It really isn't an issue though.
 
I am either an eternal optimist or I have my head in the sand :D

Will check out the Eibach catalogue later, thanks! 30mm drop is a lot really over the stock suspension. No wonder Bilstein recommends the B8 over the B6 in this application especially as the springs get older and sag. No one uses or found springs that give the same drop as the M sport ones or at most 20mm drop?

I did find the spring rates for the M sport springs and am reproducing them here as follows:
Front: 160-220 lbs with 1-4 inches of travel
Rear: 240-420 lbs with 1-4 inches of travel

Would be good to find similar progressive springs as the M sport ones without the tendency of them breaking. Might have to look at Swift or Hyperco catalogue to see if any fits.
 
This looks promising as an alternative to the infamous M sport spring:
https://www.ecstuning.com/BMW-Z4-3.0i-M54_3.0L/Suspension/Springs/ES2915132/

Since my M sport springs are still intact and there is now a vendor that can supply replacements (OE or OEM), I have decided to just swap the current absorbers to new Sach/Boge M sport units.

This will allow me to refresh and experience the original M sport suspension and act as a baseline for me to determine if the ride quality is suitable for the kind of roads, driving that will be done in our part of the globe.
 
You must log in or register to reply here.
Back
Top Bottom