Review: 3DM Öhlins R&T kit + TMS camber plates + Syncro Design Works tension arms

[IamFODI]

So you bought completely new plates instead of new bearings/seals? Do you have any pictures of the torn seals? I don't like the way the seals in the E46 M3 Hybrid plates work, but they are what they are.

Correct. Mainly because I didn’t know what was involved, couldn’t find instructions/guidance, and didn’t want to risk another project, more delays, etc.

Now that I have everything apart, it looks pretty straightforward TBH.

This is the only pic I have:

This is of the one with the play in the monoball. The other one wasn’t all smashed to the side like that but its dust seal had similar looking cracks, which turned out to be all the way through.

[K-Dawg]

So you bought completely new plates instead of new bearings/seals? Do you have any pictures of the torn seals? I don't like the way the seals in the E46 M3 Hybrid plates work, but they are what they are.

[IamFODI]

After some minor drama, the front coilovers are back together with 203mm Hyperco springs in place of the old 178mm Swifts.



Looks like about 20mm of preload with the spring perches at their absolute lowest setting. This yields a roughly 50/50 bump/droop ratio at the point of bump stop engagement, by which point the springs should be delivering around 330 lbs more force. Hoping all of that makes bump stop hits less frequent and less horrible.

Per the spring's spec, it should be at least 5 mm short of coil bind even when the bump stop runs out of give. So, hopefully no coil bind from here on.

Though, ironically, I might never know because roads around here are night-and-day better than before. Which, honestly, would be fine by me...

I put a few miles on the car since putting everything back together and it seems the noise I had been chasing is gone. So, I guess it was the worn camber plate monoballs after all.

Ended up having a conversation with FK, who makes the monoball in the TMS Hybrid camber plates. Monoball camber plates are a weird application for spherical bearings: they load the bearing axially, which spherical bearings are not designed for and not very good at. For applications with high axial load, the FK rep recommended the "F1 fit" variant, which is tighter and should be able to take more load. Apparently ECS uses the looser F2 fit in their plates. Food for thought for a future rebuild.

[IamFODI]

Did a spring-off test to make sure the wheel wouldn't rub with the amount of bump travel I calculated I'd have with the new 203mm Hyperco springs. Seemed to pass, so I'm proceeding with the spring swap to gain bump travel and hopefully prevent coil bind.

Also decided to break in a new kitchen scale by weighing the old and new springs.

Old 178mm Swift:


New 203mm Hyperco:


Only 6.6 oz difference per spring.

Surprisingly to me, the Hyperco only weighs 0.1 oz more per mm of length. I expected a bigger difference in favor of Swift given the hype.

[IamFODI]

New issue: In trying to hunt down a noise that I think is suspension-related, I found the boots on both camber plate monoballs were torn. No idea how long they were like that but there is definitely play in at least the passenger's side monoball. If that isn't the source of the noise, I'm guessing it will be soon.

I was a hair's breadth from using this situation as an excuse to switch to other camber plates. But ECS is running a killer sale RN that puts the TMS Hybrid at the price of the GC Street or Vorshlag. GC says their Street plates will only give up to -1.5º of camber, which is less than I need. GC Race and Vorshlag will do more, but still have unsealed monoballs. So, I guess I'll be sticking with TMS Hybrids.

Only consolation in all this is that the M3 will be seeing fewer miles from now on as we've added another car to the stable. So, hopefully whatever camber plates I buy next will last longer than 3 years and 40k miles.

[IamFODI]

Taller spring, move the perch down.

That's the plan.

[Tbonem3]

You don't want to raise the car? Taller spring, move the perch down.

[IamFODI]

Total travel or useable travel?

Total. They don't list usable.

[Obioban]

Thanks. I did see that series. Best match looks like 0800.2530.0350, with 131mm travel – 2.8mm less than the Hyperco option I saw (188B0350), and only 1mm more than what it'd see in use. 😕

Total travel or useable travel?

[IamFODI]

I ended up using Eibach's extreme travel line of springs for this reason. They're basically linear rate barrel springs designed for use in coilovers, and have a bit more travel than other options of similar length (and eibach claims the entire travel is useable travel, whereas most spring aren't supposed to be used right to the point of coil bind).

Thanks. I did see that series. Best match looks like 0800.2530.0350, with 131mm travel – 2.8mm less than the Hyperco option I saw (188B0350), and only 1mm more than what it'd see in use. 😕

[Obioban]

I ended up using Eibach's extreme travel line of springs for this reason. They're basically linear rate barrel springs designed for use in coilovers, and have a bit more travel than other options of similar length (and eibach claims the entire travel is useable travel, whereas most spring aren't supposed to be used right to the point of coil bind).

[IamFODI]

Well, looks like this thread will need a serious revision soon.

After a bunch more bump stop hits, I finally had enough and reached back out to Barry. He suggested increasing front preload further to gain more bump travel – but then realized that might risk coil bind, so we concluded some measurements are in order.

Got into the wheel wells today to take those measurements. Looks like I'm getting coil bind already:



This is with 9mm of preload on the front springs (slightly more than the kit ships with). Assuming 113mm damper travel and 5mm bump stop length when fully compressed, that means the spring could see up to 117mm of compression in use. Swift's specs for this spring indicate a max travel of 4.6", which calculates out to 116.84mm. So, to put it mildly, there doesn't seem to be any more room to add preload with this spring. Even if I'm misreading those marks on the springs, the calculations suggest there's zero room for error.

The next size up in Swift's catalog is a 203mm long spring with considerably more available travel. Unfortunately, the threaded section of the damper body isn't long enough to easily accommodate it, so I'd have to run something like 22 mm of preload. All-in, the total compression would be only 2mm shy of the spring's max. Better, but not by much.

I scanned the ERS and Hyperco catalogs for a spring with more travel. I found exactly one: a Hyperco that'd yield 3.8 mm of breathing room.

Not sure what I'm going to do at this point. I first need to verify the bump stop specs to make sure I know what I'm working with. Whatever the case, though, I'm going to take this as yet another sign of the risks of messing with a fully engineered kit. If I had just stuck with one of 3DM's top mount options instead of the TMS camber plates, I could run a longer spring without issue. Now I have to worry about potential damage to the strut towers and other things, which I really didn't need in my life.

[ultimatemj]

Wait, the Ohlins don't have 150m of travel?? DOH!
If that's the case, these won't ride much better than the coilovers I'm coming from

[IamFODI]

Considering mine are about to be installed, this would be really helpful to know ASAP

Being the design adjust ride height via raising and lowering the body, I'd hope the design has (at least) the stock amount stroke with the 6mm spring preload (indicated in the install manual).

Total travel is something like 1.2" less than stock. It's definitely a short damper. But with default settings, most of the loss is in droop. Bump travel is comparable to stock; maybe slightly more if my calculations are right.

There are some asterisks on the bump travel comparison though. The stock bump stop is long; it engages after 0.5" or less of bump travel, and then it has another 1" or so of compression before it runs out of give. The Öhlins kit with out-of-the-box settings has about 1" of bump travel before engaging the bump stop, and then another 0.8" before the bump stop ends.

[ultimatemj]

Obioban Are these ohlin kits still suffering from the lack of travel discovered by and needing to use TMS plates, etc?

Considering mine are about to be installed, this would be really helpful to know ASAP

Being the design adjust ride height via raising and lowering the body, I'd hope the design has (at least) the stock amount stroke with the 6mm spring preload (indicated in the install manual).