True coilover rear set up and strut turrets

[DavidStr]

Hi all,
I am considering upgrading dampers on my M4 and I have seen many companies offer a true coilover rear set up, which seems interesting for ease of adjustment.
But I struggle to find info on the rear strut tower strength if going that way with relatively high spring rates.
Has anyone tried this set up and what are the thoughts?
Thanks for the advice
David

[bracer]

I'm running MCS true coilover. The F80 is super beefy around the towers. I seriously doubt we will see any issues like there were in previous generations.

[DavidStr]

What spring rate are you using?

[x.shell]

Originally Posted by DavidStr

Hi all,
I am considering upgrading dampers on my M4 and I have seen many companies offer a true coilover rear set up, which seems interesting for ease of adjustment.
But I struggle to find info on the rear strut tower strength if going that way with relatively high spring rates.
Has anyone tried this set up and what are the thoughts?
Thanks for the advice
David

People that have converted to a true coilover set up in the rear report that no reinforcement is needed on the strut tower. Apparently, it's beefed up quite a bit more than the E9X gen.

What spring rates do you plan on going with? With a true coilover set up, you should be going with softer a spring rate when comparing to the OEM divorced spring set up. Some mathematical calculations will be required to figure out the exact spring rate you desire.

[bracer]

Race Season is 800F 700R

Comfort Season is 400F 350R

[DavidStr]

I have been advised 670 front and 560 rear

how does it sound?

[x.shell]

Originally Posted by blackey

Race Season is 800F 700R

Comfort Season is 400F 350R

If I had the luxury of going blackey 's route (two set ups), I think those are perfect spring rates for the track vs street.

Originally Posted by DavidStr

I have been advised 670 front and 560 rear

how does it sound?

DavidStr , if you take tracking your car semi-seriously, then I think those rates would be good. However, if street driving is priority for you, then I personally think it's too stiff. I found 350-450 on the front to be most comfortable for street driving. The rears seem fine either way.

I have to stress that this is my opinion. Everyone has a different tolerance on what is acceptable for street comfort; this is what's comfortable for me around LA. Tracking on the other hand, optimal set up can change based on the track, other suspension components, tires, etc.

[bracer]

Springs on this car with camber plates, etc... can be done in less than an hour btw.

[Pic18]

Originally Posted by blackey

Springs on this car with camber plates, etc... can be done in less than an hour btw.

I know in the front you could just loosen the strut shaft from the camber plates and remove the strut with the plates still attached to the car to avoid changing camber, but in the rear you need to remove (drop) the lower control arm are to get at the shock correct? I realize you can mark the eccentric bolt but any concerns on affecting camber in the rear during a change/swap?

[x.shell]

Originally Posted by Pic18

I know in the front you could just loosen the strut shaft from the camber plates and remove the strut with the plates still attached to the car to avoid changing camber, but in the rear you need to remove (drop) the lower control arm are to get at the shock correct? I realize you can mark the eccentric bolt but any concerns on affecting camber in the rear during a change/swap?

Yes, you will most likely have to drop the control arm to swap springs in the rear. If you want to keep the same camber settings, just mark all the bolts with a Sharpie before loosening. That way you can go back to the correct settings.

If you change springs to a different rate or raise/lower the height, you will have to adjust the camber and toe settings again anyways. Some people get their alignment done with their different springs and mark them with different colored Sharpies or paint marker. This way you can always go to your preset camber/toe settings when you swap between springs. Still, others have the patience and know-how to do the alignment on their own.

[Pic18]

Originally Posted by x.shell

Yes, you will most likely have to drop the control arm to swap springs in the rear. If you want to keep the same camber settings, just mark all the bolts with a Sharpie before loosening. That way you can go back to the correct settings.

If you change springs to a different rate or raise/lower the height, you will have to adjust the camber and toe settings again anyways. Some people get their alignment done with their different springs and mark them with different colored Sharpies or paint marker. This way you can always go to your preset camber/toe settings when you swap between springs. Still, others have the patience and know-how to do the alignment on their own.

Like I said in my comment I know you can just mark the bolt, but I would still be concerned things moved around a bit. Likely it wouldn’t really be enough to have a major effect (maybe a quarter degree or less?) which would make realigning each time not really worth it. Nonetheless I think I would rather live with one set of springs and crank down the rebound and compression on the street rather than switching back and forth. Just my two cents.

[bracer]

For toe if you are using aftermarket toe links you can get the bolts that fix that point. I usually just drop the lower a-arm to spindle bolt out (marking it for camber) with a jack underneath and let it come down. With stock springs that will not be enough, but if you are already running aftermarket that works fine.

I'm on true rear coilovers which makes it even easier as the lower spring perch is slotted and just slides out. Then you just need to remove the lower shock bolt and you're set. That really just two bolts to change a spring out per side. (and a jack)