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

[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]

Total travel or useable travel?

Total. They don't list usable.

[Tbonem3]

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

[IamFODI]

Taller spring, move the perch down.

That's the plan.

[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]

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]

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.

[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]

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.

[bavarian3]

Thanks for this great thread and review. I thought I would add some spring weights to your thread for data points.

Based on this, due to weight, I think I'll need to find new front springs. These are for e46 m3 btw if it makes a difference.

Front Ohlins RT



Rear

[IamFODI]

Thanks for this great thread and review. I thought I would add some spring weights to your thread for data points.

Based on this, due to weight, I think I'll need to find new front springs. These are for e46 m3 btw if it makes a difference.

Yeah, I think E9x springs will be different. The car is a bit heavier, front suspension is a little different, rear suspension is very different. Assuming your scale is showing lbs and oz, that rear spring is way lighter than the E9x's. The front is in the same ballpark, though, so a Swift or Hyperco option should be lighter for sure.

[Grke46m3]

Yeah, I think E9x springs will be different. The car is a bit heavier, front suspension is a little different, rear suspension is very different. Assuming your scale is showing lbs and oz, that rear spring is way lighter than the E9x's. The front is in the same ballpark, though, so a Swift or Hyperco option should be lighter for sure.

What's the advantage of going with a swift or hyperco vs a custom ohlins from 3ddm? Swift and hyperco have a longer spring?


Sent from my iPhone using Tapatalk Pro

[IamFODI]

What's the advantage of going with a swift or hyperco vs a custom ohlins from 3ddm? Swift and hyperco have a longer spring?

At the time I bought the kit (~4 years ago now – holy smokes), Swift springs were lighter than the ones Öhlins was using (not sure if this is still true).

Then it turned out the Swift springs I had up front were too short and caused coil bind, so I looked for longer springs with more compression travel; Hyperco and Swift both had options, but Hyperco's option seemed to offer slightly more compression travel according to the specs, and I got the impression that the risk of permanent deformation from near-full compression isn't as much of a worry with Hyperco as with Swift. So, I went with Hyperco.

I brought all of this headache on myself by insisting on

1. A particular camber plate, which threw off the dimensions, and
2. Maximum weight savings – as in, fractions of a pound.

If you just go with Öhlins's camber plates or the stock mounts, and if you aren't obsessed with saving ounces of mass, just do what Öhlins/3DM tells you to do and you'll have a great life.

[HC1963M3]

I think your last post is telling…
I’ve been through this exact same process albeit with a Porsche 996 C2.

I too wanted minimal or no increase in NVH, but I wanted the benefits of vastly improved damping AND increased compliance.
4 sets of springs later …

The spring rates Ohlins provided for the 996 when the initially released their R&T kit, were, quite frankly, ludicrously high. Many individuals complained (I suspect the majority) and Ohlins finally released a spring set with revised/lower rates. Many chose to retrofit the revised springs (at great cost I may add)

I elected to buy the R&T dampers without springs and chose my own rates. It was a long, expensive and tortuous process, but the results were worthwhile, though I have to say, I would not entertain doing the same again.

I chose the Ohlins R&T kit for several reasons :

I'd utilised a set of Ohlins 3 way adjustable remote canister race dampers on a street 996 GT3 previously. They had to be custom built with longer bodies, different damper shafts, along with spring rates roughly a 1/4 of those used on the race car, and suitably re-valved to suit the lower spring rates. The results used solely as a fast street car, were truly exceptional. That was ten years ago, and I’ve yet to experience better damping on any car.

The R&T kit utilises the stock rubber front and rear damper top mounts fitted to the non-GT3/RS cars. Having previously owned numerous 996 and 997 GT cars, I came to hate the increased NVH transferred through to the cabin, courtesy of the stock spherical bearing adjustable top mounts. So the fact the R&T’s were compatible with the OE, non-spherical bearing, non-adjustable top mounts was perfect for my needs. But there was a caveat, and it’s relevant to your trials and tribulations with the adjustable top mounts you specified …

I wanted to be able to adjust/increase the front end camber, and whilst the factory sheet metal of the front suspension top mounts allows for camber adjustment, the amount is minimal (less than 3/4 degree of negative camber) and I knew I’d most likely be looking for double that, and possibly slightly more.

To further complicate matters, I wanted to retain the car’s stock wheels, which are light, easy to clean and strong, but have weak offsets and don’t fill the fenders convincingly.
Many car owners seem happy to bolt wheel spacers anything from 5-15mm thick to the front of their front hubs to ensure their wheels fill out the fenders. I refuse to do this point blank.
So I effectively wanted a wide track front axle arrangement that didn’t utilise wheel spacers to gain the additional width.

Thinking outside the box I elected to use adjustable lower arms to increase the track width, and use all the available positive camber adjustment at the top mounts to enable widening the track as much as possible.

This however effectively lengthened one side of the front suspension mounting point "triangle” which meant one side would be shorter, in this case it was the caster arm which had no adjustability, which in turn threw the caster settings, which meant I now needed adjustable caster arms...

I was adamant that I didn’t want to use Rose jointed camber or caster arms (as doing so would have introduced further NVH) but also because the British weather is not kind to spherical bearings, and many of the aftermarket components utilise open Rose joints to make their adjustment quick and easy both in the workshop and at the racetrack.

So I spent many hours trawling the internet to find adjustable arms that utilised OE bushes or high quality sealed spherical bearings.

In the end two American companies supplied the components I needed SPC and Hardrace :

https://hardraceshop.com/products/hardrace-porsche-986-front-only-987-front-only-996-997-front-rear-caster-arm-pillow-ball-2pcs-set-v2?variant=44780076859704&country=GB&currency=GBP& utm_medium=product_sync&utm_source=google&utm_cont ent=sag_organic&utm_campaign=sag_organic&srsltid=A fmBOoqkWxpqHFSxGew2Z_hhgru1tSVdF9YNay4o7oey6icUODP 4sUhFf_Y

https://www.spcalignment.com/component/spc/?task=part_description&pid=72610

Whilst undoubtedly considerably more expensive than using adjustable top mounts with spherical bearings, the end result enables much increased camber (and the ability to adjust the caster settings) whilst retaining OE levels of NVH.

Playing with camber, toe and caster settings has allowed me to achieve “go-kart” like levels of turn in without any of the usual downsides: tramlining, hunting out surface camber on poorly repaired roads, excess tire wear etc etc.

SPL (note not SPC) make adjustable front camber arms for the E9X M3 :

https://www.splparts.com/products/bmw-e9x-e8x-front-lower-control-arms.html

Personally I’d look to replace that inner Rose joint with something from SPC’s range of xAxis sealed monoballs :

https://www.spcalignment.com/images/stories/flyers/BuildersSeries2015FlyerWEB.pdf

https://www.spcalignment.com/component/content/article?id=337

Or utilise an upgraded though OE type rubber or poly bush.

SPL also make adjustable caster bushings for the E9X M3 :

https://www.splparts.com/products/bmw-e9x-e8x-f8x-adjustable-front-caster-rod-monoball-bushings.html

Utilising both the SPL components would enable you to use the stock rubber top mount whilst giving you the ability to adjust the camber and caster albeit with the added benefit of far better front suspension location.


With hindsight, I wouldn’t have chosen the Ohlins R&T’s for one major reason, that being they utilise one adjuster for adjusting both compression and rebound damping, what they don’t tell you is the split between that bump and rebound control/adjustment is heavily biased towards rebound (the ratio is roughly 80% rebound 20% compression)

If you elect to utilise the spring rates originally specified with the dampers, I think that combined adjuster provides "acceptable" adjustment, but once you go off piste with spring rates, you’re going to be compromised when it comes to finding damping settings compatible with those reduced spring rates. In which case a damper with independent compression and rebound settings would be preferable IMO.

I "get" your wish to save weight, or at the very least not add heavier components, but experience tells me it's utterly futile unless you're chasing every last pound of weight with a view to extracting maximum performance on track.
If you want to reduce unsprung weight, ditch the stock wheels for something lighter, ditto the brake rotors and calipers, and lastly find the lightest tires available, but as we both know, that lot will cost many thousands of $$ and is pointless when the car has seats, a battery, exhaust system and numerous other components that weigh vastly more than they need to, all in the interests of cost cutting by the manufacturer ...