Need feedback on suspension bushing upgrades

[IamFODI]

Looking at bushing upgrades and interested in some opinions. I really want the handling and feel benefits of solid bushings/bearings where there’s rubber in the stock suspension, but I’m leery of potential downsides.

Questions:

1. Can anyone comment on the NVH increase (amount and type) with both front tension arm monoballs and camber plates with spherical bearings? I’ve read that each of those mods individually adds minimal NVH if done right, but I have yet to read any commentary on both together. I believe the only rubber left in the front suspension at that point would be the spring isolators…

2. Bimmerworld and 3DM have ball joint replacement kits for the rubber bushings in the rear camber arms (BW) and trailing arms (3DM). Any comments on NVH from those?

3. Is there a reason other than NVH for any of the rubber bushings in the rear suspension? I know sometimes rubber bushings are used when a suspension arm needs to move other than axially; in those cases, swapping in a ball joint can cause crazy local stresses and potentially break stuff. Is that the case for any of this car’s rubber bushings in the back?

[SYT_Shadow]

Hi

I have all the mods you describe.

Front tension arms from BW have zero NVH, it is the best mod. I have it on my 3 M3s and if I were to get a 4th I'd do that immediately.
Camber plates always introduce some nvh, even the gc street ones which I have. My street M3 doesn't have them for this reason, although it is very slight.

For the rear I have the BW solid bushing. I did this years ago and have yet to notice any noise/strangeness coming from the rear suspension.

[IamFODI]

Thanks, SYT.

Camber plates: Could you comment on what kind of NVH a spherical bearing would add on a car that already has front tension arm monoballs? Is it impact harshness or just noise? Can it be felt in the steering, seat, or both? Also, any perceptible handling/feel benefits?

[Obioban]

I'm running turner hybrid camber plates on my M3 coupe, and they're as close to "best of both worlds" as it gets, imo. You get the articulation and most of the precision of the monoball, but the monoball is poly isolated, so most of the NHV that normally comes from monoball camber plates is dialed out. The poly isn't used as bushing (no deflection demanded of it), just as NHV isolater.

Plus the monoball is sealed from the elements, unlike most other plates, so it should last longer for street use (especially given that you're winter driving the car).

They make an e9X M3 version: https://www.turnermotorsport.com/p-5...te-kit-hybrid/

They also use an OE BMW thrust bearing, so you don't get any low speed steering weirdness (some plates don't, which means the spring either has to slide/hop on the adjuster or twist when you turn... both of which feel weird).

I took the long way to get to these (TCK monoball to GC street to TMS hybrid), but they address all the complaints I've had with previous plates and combine their best attributes. I'm also running their hybrid RSMs at this point, which have a similar design.

[SYT_Shadow]

Thanks, SYT.

Camber plates: Could you comment on what kind of NVH a spherical bearing would add on a car that already has front tension arm monoballs? Is it impact harshness or just noise? Can it be felt in the steering, seat, or both? Also, any perceptible handling/feel benefits?

The GC Street plates had a very slight clunking that I would hear every now and then. It was very subtle but it existed, and as the E92 is a full street car I didn't feel the need to have lots of camber on it.
It's not like this was keeping me up at night due to the sound


Obioban I am not sure what the difference between the GC Street plate and the Turner hybrid plate are.

[Obioban]

The GC Street plates had a very slight clunking that I would hear every now and then. It was very subtle but it existed, and as the E92 is a full street car I didn't feel the need to have lots of camber on it.
It's not like this was keeping me up at night due to the sound


Obioban I am not sure what the difference between the GC Street plate and the Turner hybrid plate are.

At least on the e46, the GC street plate has no monoball (edit: just checked-- this is also the case on e9x)-- so any articulation required has to happen through bushing deflection, which in turn means the shock can't be precise (as the bushing can also deflect that way, and will do so more with a softer bushing. On the TMS hybrid, the bushing is solely responsible for NHV mitigation, as the monoball handles the deflection. This means they can get away with a much stiffer bushing, so the shock can be more precise. BMW's OE monoballs that they use pretty much everywhere they use a monoball operate the same way-- monoball to handle the deflection, nylon to absorb NHV.

[Obioban]

Unrelated to the above: If the same arm design is available from multiple vendors, I'd get it from not bimmerworld. They have a history of claiming to use OE BMW monoballs, but actually using something far cheaper if you take them apart to inspect...

[IamFODI]

Thanks, Ian.

For context: my overall goal is to improve agility and sharpen feel while keeping primary and secondary ride comparable-or-better vs. stock (though slightly more noise is tolerable). Barring any major revelations, I'm pretty much set on Ohlins R&T with Swift springs from 3DM. 3DM sells Vorshlag camber plates, which have spherical bearings. If I can achieve my goals with those, I don't need to do any better NVH-wise.

IOW, I'm not looking for the best handling/NVH balance per se. I just need NVH to be not-worse-than-stock overall in most situations. As long as the total setup clears that bar, I'll take all the precision I can get.

I heard from Jason at Vorshlag that, in most applications, the NVH added by their camber plates is comparable to upsizing wheels or switching to runflats. He also said it'll make the car more sensitive to tire balance issues. OTOH, with Ohlins R&T dampers, and Swift springs that aren't too much stiffer than stock, I'd expect better secondary ride.

So, overall, I'm imagining there'd be a little more of the highest-frequency NVH (sound and vibration), but the same or less of the rest (thuds etc.) vs. stock. I realize there's no way to know whether that's completely accurate; I'm really just looking for someone to tell me whether I'm in the ballpark with that hypothesis.

[S14]

Hi

I have all the mods you describe.

Front tension arms from BW have zero NVH, it is the best mod. I have it on my 3 M3s and if I were to get a 4th I'd do that immediately.
Camber plates always introduce some nvh, even the gc street ones which I have. My street M3 doesn't have them for this reason, although it is very slight.

For the rear I have the BW solid bushing. I did this years ago and have yet to notice any noise/strangeness coming from the rear suspension.

What are front tension arms?

[SYT_Shadow]

What are front tension arms?

the 'brake' arms, basically this: https://www.bimmerworld.com/Suspensi...93-M3-E82.html

I've been using this on 3 M3s for the past 5 years, it works perfectly. I'd even use this if I had a E93 M3

[S14]

the 'brake' arms, basically this: https://www.bimmerworld.com/Suspensi...93-M3-E82.html

I've been using this on 3 M3s for the past 5 years, it works perfectly. I'd even use this if I had a E93 M3

Gotcha, didn't realize what section I was in, I'd never heard that term for E30/E36/E46 chassis (their front ends are all similar)

[SYT_Shadow]

Gotcha, didn't realize what section I was in, I'd never heard that term for E30/E36/E46 chassis (their front ends are all similar)

No worries

The E46 doesn't have anything going from the kingpin to the front end of the car

[Obioban]

Yeah-- the closest e46 equivalent to this is monoball FCABs.

[IND-Distribution]

For the back, we are big fans of our Future Classic Teflon-lined spherical RTABs. You get the elimination of unwanted flex and far more precise suspension tuning while rubber dust boots on the outside keep debris out and the grease in. There is no increase to NVH. We also offer reinforced trailing arms if you're not going adjustable or can't due to class restrictions.

[SYT_Shadow]

Yeah-- the closest e46 equivalent to this is monoball FCABs.

I think the difference is the e9X monoballs do 0 for nvh but the fcabs of the e46 tend to. Maybe by now some don't, but in the e9x none do