MCS 1WNR or 2WR?

[stevehifi]

turner makes a camber plate.

I would send your rear setup back and have them convert to a true coilover that way you don't need the rear height adjuster.

[MR RIZK]

Originally Posted by stevehifi

turner makes a camber plate.

I would send your rear setup back and have them convert to a true coilover that way you don't need the rear height adjuster.

I suspect he has gone with the divorced rear to remove any issues with the swaybar clearance. Also he has already purchased springs which will be the wrong rate if moving to a CO setup in the rear.

Sending the dampers in is not required as the valving will be fine. Just needs the lower offset bushes for the control arm,lower extended spring seat and upper spring seat.

[rborane]

You could also go coilover rear. Rear shocks are the same (I've confirmed with BW), so you would just need the upper and lower spring perch, lower shock bushings, and upper spring plate. Bimmerworld will recommend to run the spring position upright to clear the sway and in a 2.25" ID - 6" length as well. Coilover rear would make adjustments easier as well.

[heyyouduh]

Originally Posted by rborane

You could also go coilover rear. Rear shocks are the same (I've confirmed with BW), so you would just need the upper and lower spring perch, lower shock bushings, and upper spring plate. Bimmerworld will recommend to run the spring position upright to clear the sway and in a 2.25" ID - 6" length as well. Coilover rear would make adjustments easier as well.

Funny you guys mentioned this as I actually am thinking about this as well. For reference: https://f80.bimmerpost.com/forums/sh....php?t=1434992

this thread shows in order to run the true rear coilover set up all I'd need would be new 2.25ID springs (in the thread I linked they used a 8" length, no helper, obviously in a lower rate), 2.25ID spring perch, locking perch, the spring perch for the other end and offset bushings to have swaybar clearance (if I run the shock upside down with shock body down).

I'll call GC one more time after the holiday weekend and see how long the wait time is for the camber plates and rear height adjusters, if it's going to take a long time I think I'll call up BW and convert the rears to a true coilover set up and go with a Vorshlag camber plate. As mentioned earlier in the thread Eibach is backordered on alot of springs, but I've checked summitracing/pitstopusa/ebay/etc and they have a bunch of 2.25ID spring selection that I could make it work.

[rborane]

Originally Posted by heyyouduh

Funny you guys mentioned this as I actually am thinking about this as well. For reference: https://f80.bimmerpost.com/forums/sh....php?t=1434992

this thread shows in order to run the true rear coilover set up all I'd need would be new 2.25ID springs (in the thread I linked they used a 8" length, no helper, obviously in a lower rate), 2.25ID spring perch, locking perch, the spring perch for the other end and offset bushings to have swaybar clearance (if I run the shock upside down with shock body down).

I'll call GC one more time after the holiday weekend and see how long the wait time is for the camber plates and rear height adjusters, if it's going to take a long time I think I'll call up BW and convert the rears to a true coilover set up and go with a Vorshlag camber plate. As mentioned earlier in the thread Eibach is backordered on alot of springs, but I've checked summitracing/pitstopusa/ebay/etc and they have a bunch of 2.25ID spring selection that I could make it work.

Yep. Just ask bimmerworld, as when I spoke with them they recommend to run a 6" rear spring in the top position (non-inverted) with equal length bushings to sit above the sway, and keep the shock in a straight line of travel.

To run inverted you will need the deep spring cup from MCS and the lower offset bushings to push shock further away from the sway bar. Convenience about inverted is you can access the rebound adjustment easy. I will probably end up going this route soon too.

[heyyouduh]

Originally Posted by rborane

Yep. Just ask bimmerworld, as when I spoke with them they recommend to run a 6" rear spring in the top position (non-inverted) with equal length bushings to sit above the sway, and keep the shock in a straight line of travel.

To run inverted you will need the deep spring cup from MCS and the lower offset bushings to push shock further away from the sway bar. Convenience about inverted is you can access the rebound adjustment easy. I will probably end up going this route soon too.

gotcha. makes sense about running equal lengthed bushings for the lower control arm to keep shock in a straight line - is accessing the adjuster in this configuration (shaft up, adjuster up top) that difficult that you'd wanna flip it around?

[rborane]

Originally Posted by heyyouduh

gotcha. makes sense about running equal lengthed bushings for the lower control arm to keep shock in a straight line - is accessing the adjuster in this configuration that difficult that you'd wanna flip it around?

I'm currently running my rear shocks inverted, as I'm divorced rear right now with 900lb springs, but that's the big question I'm trying to decide on when I convert to coilover rear also, if I should have it right side up or inverted. Probably only takes jacking the car up just a bit, but it is convenient to adjust it on the bottom.

For what it's worth, M4 GT4 run with the spring at the top position in a coilover rear.

[MR RIZK]

With the adjuster on the bottom you can reach it pretty easily without jacking the car as long as you are willing to lie on the ground. Even if the car is lowered 20mm.

Well I can and I'm no athlete..

[heyyouduh]

Originally Posted by MR RIZK

With the adjuster on the bottom you can reach it pretty easily without jacking the car as long as you are willing to lie on the ground. Even if the car is lowered 20mm.

Well I can and I'm no athlete..

yea it seems def it would be easier than having it on top and I'd like to run it inverted if possible.

I get pains sometimes from just... doing nothing. getting old is not fun lol

[heyyouduh]

Originally Posted by rborane

I'm currently running my rear shocks inverted, as I'm divorced rear right now with 900lb springs, but that's the big question I'm trying to decide on when I convert to coilover rear also, if I should have it right side up or inverted. Probably only takes jacking the car up just a bit, but it is convenient to adjust it on the bottom.

For what it's worth, M4 GT4 run with the spring at the top position in a coilover rear.

any potential downsides from running a true coilover set up in the rear aside from fitment issues? biggest thing I found was prior generations had questionable ability to support the load of the car at the shock mounting point and needed reinforcement. doesn't seem like this is a problem with the F8x gen. You're introducing non co-axial forces to the shock I would imagine, but not sure how big a real issue this is.

[MR RIZK]

There has been no reported issues of the upper tower tearing that I have come across. If it was an issue most of the vendors would pull the products or have a waiver etc

The downsides are the clearance issue and the additional ratio added due to the angle of the damper. Not sure how relevant it is but I have mocked up replacement double sheer mounts that take into consideration the offset. Need to see what it costs to get it CNC'd.

I was bored and wanted to learn some 3D

[heyyouduh]

Originally Posted by MR RIZK

There has been no reported issues of the upper tower tearing that I have come across. If it was an issue most of the vendors would pull the products or have a waiver etc

The downsides are the clearance issue and the additional ratio added due to the angle of the damper. Not sure how relevant it is but I have mocked up replacement double sheer mounts that take into consideration the offset. Need to see what it costs to get it CNC'd.

I was bored and wanted to learn some 3D

that's pretty cool. as an update GC was for some reason open today (most places are not since today is the observed holiday for 7/4 in the US) and they do have the camber plates and rear height adjusters in stock, expect it to go out some time this week. Hopefully I can get in contact w/ BW and ask for expedited shipping as I'm off this week and would like to get it all done and on the car. When I do I'll post some pics.

[SYT_Shadow]

Originally Posted by MR RIZK

There has been no reported issues of the upper tower tearing that I have come across. If it was an issue most of the vendors would pull the products or have a waiver etc

The downsides are the clearance issue and the additional ratio added due to the angle of the damper. Not sure how relevant it is but I have mocked up replacement double sheer mounts that take into consideration the offset. Need to see what it costs to get it CNC'd.

I was bored and wanted to learn some 3D

Correct. The F8X has a large piece to spread out the forces from the rear shock. Completely different design than the E9X and prior gens.

No issues running rear coilovers, indeed, that should be the default option

[heyyouduh]

update:
GC has the camber plates and rear height adjuster, will be shipping them out in the next day or two. front springs I sourced and are en route as well. any retailer ordering from eibach will be at their mercy, but large retailers like pitstopusa and summit racing (and ebay sellers) have some in stock, which is nice.

that said, I discussed w/ BW about running vorshlag camber plate + rear true coilover if GC is significantly backed up, they said to run the rates I want to run I'd need a 7 or 8" long spring in the rear to avoid coil bind, but those lengths would as expected give clearance issues, whether you run the shock right side up or inverted. they do not recommend the offset bushing method as they consider it not an ideal solution. they're working on a rear sway bar set up so clearance will not be an issue. they gave me the option to run a 6" length spring at higher rates to avoid coilbind, but I wasn't willing to go stiffer for my purposes. anyway, moot point since (hopefully) I'll get the GC hardware soon and take advantage of my week off. I think I annoyed BW enough with calls and emails.

documenting this in hopes of adding to the collective database here.

[MR RIZK]

That's correct. But it isn't just the length of spring it also ties into the useable travel. Hence reviewing specs from the spring manufacture is crucial.

In my case a 6" 8kg swift spring in the rear will coil bind. Moving to a 7" 10kg spring alleviated the bind. They both have the same usable travel but the higher rate mitigates the coil bind. My final setup is 12/10kg

If you end up running CO and helpers in the rear then stick with 7" as 8" will not leave sufficient height adjustment.

Regarding the alternate swaybar setup from bimmerworld, this has been in the works for a long time so hopefully one day it comes to light.

[stevehifi]

Originally Posted by heyyouduh

update:
GC has the camber plates and rear height adjuster, will be shipping them out in the next day or two. front springs I sourced and are en route as well. any retailer ordering from eibach will be at their mercy, but large retailers like pitstopusa and summit racing (and ebay sellers) have some in stock, which is nice.

that said, I discussed w/ BW about running vorshlag camber plate + rear true coilover if GC is significantly backed up, they said to run the rates I want to run I'd need a 7 or 8" long spring in the rear to avoid coil bind, but those lengths would as expected give clearance issues, whether you run the shock right side up or inverted. they do not recommend the offset bushing method as they consider it not an ideal solution. they're working on a rear sway bar set up so clearance will not be an issue. they gave me the option to run a 6" length spring at higher rates to avoid coilbind, but I wasn't willing to go stiffer for my purposes. anyway, moot point since (hopefully) I'll get the GC hardware soon and take advantage of my week off. I think I annoyed BW enough with calls and emails.

documenting this in hopes of adding to the collective database here.

For the rear 'true coilover setup':
Every major motorsport coilover brand (AST, Moton, Ohlins, Nitron) run the lower offset bushing on the shock lower mount to clear the swaybar in the rear. There is no issue with it. In fact I bet BMW does the same thing on their M4 GT4 with their Ohlins TTX true coilover on the rear.

Here's an example of a Nitron 3way: https://www.teamschirmerparts.com/co...37926604177595

I'm not sure why BW says it's an issue please show me the proof - it's definitely more of an issue to run a shorter than needed spring as a workaround (bad idea). Most suspensions I've seen run a main+helper in the rear, long enough to give adequate travel which the rear desperately needs to maintain composure. (more so than the front)

True coilover is the best approach since it allows lower rates to be run and longer spring coil for better suspension travel. Plus its actually easy to adjust the ride height for a change!

[rborane]

Originally Posted by stevehifi

For the rear 'true coilover setup':
Every major motorsport coilover brand (AST, Moton, Ohlins, Nitron) run the lower offset bushing on the shock lower mount to clear the swaybar in the rear. There is no issue with it. In fact I bet BMW does the same thing on their M4 GT4 with their Ohlins TTX true coilover on the rear.

Here's an example of a Nitron 3way: https://www.teamschirmerparts.com/co...37926604177595

I'm not sure why BW says it's an issue please show me the proof - it's definitely more of an issue to run a shorter than needed spring as a workaround (bad idea). Most suspensions I've seen run a main+helper in the rear, long enough to give adequate travel which the rear desperately needs to maintain composure. (more so than the front)

True coilover is the best approach since it allows lower rates to be run and longer spring coil for better suspension travel. Plus its actually easy to adjust the ride height for a change!

Would you recommend a 7" or 6" rear spring for coilover rear? I have an extra set of hyperco helper springs (purchased from BW) which I currently run in the front, that are fully bricked under load, and deciding if I should go coilover rear eventually. If I can use the hyperco helpers, all I will need are the main springs.

I have seen some sets use swift springs / swift helpers or even thicker tender springs from Eibach, but right now I am running Eibach main with hyperco helper in front.

[stevehifi]

Originally Posted by rborane

Would you recommend a 7" or 6" rear spring for coilover rear? I have an extra set of hyperco helper springs (purchased from BW) which I currently run in the front, that are fully bricked under load, and deciding if I should go coilover rear eventually. If I can use the hyperco helpers, all I will need are the main springs.

I have seen some sets use swift springs / swift helpers or even thicker tender springs from Eibach, but right now I am running Eibach main with hyperco helper in front.

I would call MCS directly - they are very helpful and see what they recommend for their rear dampener. Try HP Autosport - they are an MCS dealer as well.

[heyyouduh]

Originally Posted by stevehifi

For the rear 'true coilover setup':
Every major motorsport coilover brand (AST, Moton, Ohlins, Nitron) run the lower offset bushing on the shock lower mount to clear the swaybar in the rear. There is no issue with it. In fact I bet BMW does the same thing on their M4 GT4 with their Ohlins TTX true coilover on the rear.

Here's an example of a Nitron 3way: https://www.teamschirmerparts.com/co...37926604177595

I'm not sure why BW says it's an issue please show me the proof - it's definitely more of an issue to run a shorter than needed spring as a workaround (bad idea). Most suspensions I've seen run a main+helper in the rear, long enough to give adequate travel which the rear desperately needs to maintain composure. (more so than the front)

True coilover is the best approach since it allows lower rates to be run and longer spring coil for better suspension travel. Plus its actually easy to adjust the ride height for a change!

I don't have enough knowledge in this to really have a more nuanced discussion or have a stronger opinion. For my purposes of a daily car that sees some track time I can understand why BW wants to keep things as simple and as "conservative" as possible. And as I mentioned, I just don't have the depth or experience to want to go against what they're recommending.

I'm glad it generated some discussion though, at the very least I wanted to document this so others looking to purchase this set up will have just one more data point to go on.

In a few years if job/family/life allows hopefully I'll be able to dive deeper into this.

[heyyouduh]

Originally Posted by stevehifi

I would call MCS directly - they are very helpful and see what they recommend for their rear dampener. Try HP Autosport - they are an MCS dealer as well.

To be completely transparent, I called MCS directly with a couple of set up related questions while I was researching the set up for the M3, they directed me to BW for more specific set up related questions. A few years ago I reached out to them regarding a custom set up for a different car as well and they directed me to a retailer/shop that time too. Not to say they weren't helpful and friendly, just seemed they prefer to forward set up specific stuff to the retailers.

I also emailed/called HP Autosports while doing my research, they were hesitant to disclose their specific spring lengths/rates to me before the purchase which is why I went with BW. Again, not to say HPA wasn't responsive or was unpleasant (they were responsive and pleasant), but seemed like they were weary of discussing too many specifics and worried that I may grab those details and just make my own kit. I'm not in this business so I can't comment on these practices, but I do understand a shop that has devoted time/money/expertise on their set up not wanting to divulge information to just any joe that called or emailed them.

YMMV

[MR RIZK]

Originally Posted by stevehifi

Here's an example of a Nitron 3way: https://www.teamschirmerparts.com/co...37926604177595

Just a observation the nitrons appear to be offset further than the mcs.

[SYT_Shadow]

Originally Posted by stevehifi

For the rear 'true coilover setup':
Every major motorsport coilover brand (AST, Moton, Ohlins, Nitron) run the lower offset bushing on the shock lower mount to clear the swaybar in the rear. There is no issue with it. In fact I bet BMW does the same thing on their M4 GT4 with their Ohlins TTX true coilover on the rear.

Here's an example of a Nitron 3way: https://www.teamschirmerparts.com/co...37926604177595

I'm not sure why BW says it's an issue please show me the proof - it's definitely more of an issue to run a shorter than needed spring as a workaround (bad idea). Most suspensions I've seen run a main+helper in the rear, long enough to give adequate travel which the rear desperately needs to maintain composure. (more so than the front)

True coilover is the best approach since it allows lower rates to be run and longer spring coil for better suspension travel. Plus its actually easy to adjust the ride height for a change!

Well, bear in mind Bimmerworld has not one, or two, but FIVE M4 GT4s. It is possible they know what they're talking about.
If you call BW, every person you speak to sits around twenty feet away from multiple GT4s in various states of disassembly.

Personally I look forward to a sway bar solution for the E9X or F8X that fits correctly. As it is, I can run the rear sway on the softest position and it fits fine, but any other position would be a no no.