Front suspension refresh

[Irhase46m3]

Hi There - As my e46 is at the bodyshop i have nothing to do but work on restoring my e92. Its been sitting for years in the garage and the rubber components are starting to show excessive wear. I was wondering if anyone had refreshed their front end suspension and what route they went? (TRW, BMW, 034) - Looks like there a few options available. Would greatly appreciate if anyone could share their experience with what is out there.

Best,
Irhase46m3

[Tbonem3]

I know a little from when I had an e82. I know the TRW arms on FCPeuro are a great buy, and are 100% the factory arms (logos ground off).

I would caution against using any non factory parts except for very specific pieces for a track car. These cars' chassis are already so great out of the box. Further, I think there are more balljoints than rubber bushings coming from the E46. Rubber bushings will need to be replaced sooner than ball bearings. Bearings, under good conditions, can go 200k. I would focus on replacing the arms/bushings with rubber and not bearings.

You could pull strut mount pins for a little more neg camber, if you haven't already.

Edit: For more background, I have a 48k 2011 e90 and just replaced springs (with swift) and shorter e36 m3 bumps, but everything felt and looked great, so I didn't replace anything else. Pulled pins as well.

Car still felt very tight at 48k, even moreso now with swifts; need a bigger bar prob too. I hope bmw used stiffer, better rubber than prev m3s. Of course, the susp design itself is better which contributes to the tighter handling I'm sure. Slicktop & true b pillar ain't bad either!

[IamFODI]

Good advice from Tbonem3.

The stock front suspension has rubber in only two places: the upper strut mount, and the front tension arm inner bushing. Everything else is a ball joint, and a pretty robust one at that.

FCP Euro sells a monoball conversion for the front tension arms: https://www.fcpeuro.com/products/bmw...n-works-e9xrwd This is the one mod I'd suggest considering, even for a street car. Everyone says no additional NVH; that's an exaggeration but it's not night-and-day. The main downside of a monoball like this is that it can wear and start clunking, but... FCP Euro. :]

Then again, it's a lot more expensive than the stock arms, so you'll have to decide whether you'll spend more and accept a bit more NVH for a slightly sharper-feeling front end.

Other than that, yeah, it's a great design stock and like Tbone said I wouldn't change anything unnecessarily. I went with those monoball tension arms I linked, plus TMS Hybrid camber plates and Öhlins coilovers, and definitely paid a price NVH-wise. I like it and have 30k miles on that setup with no apparent issues, but I wouldn't recommend it for everyone. Lots more impact and road noise, especially on bump stop hits. My front control arms and tie rods are original AFAIK, with 140k miles now and no apparent issues despite year-round DD use in the northeast plus some hard impacts.

One issue I am having is with the lower steering shaft. There seems to be excess play in one of the swivel joints, causing a minor clunk. Replacing both joints along with the shaft soon.

[Epoustouflant]

What Tbonem3 said is true, the options to upgrade the E9X M3 suspension quickly cross over into track-only territory as most arms sold by SPL, Turner and others are unsealed monoballs and require higher upkeep, and introduce more noise.

I uprated my front end for street use using really the 2x only proven options that are durable for street use: the sealed monoball upper control arms from Turner and 034 Motorsport lower control arms with uprated rubber bushings. Unfortunately they sell that as a kit with their uprated rubber bushing upper control arms.

I have upper control arms with monoballs on the E9X M3 and also just fitted a set on my E60 M5. It's a must have IMO. The front end of these cars can get wobbly under load during acceleration and breaking. Street bumps also deflect their OEM bushings quite a bit and make the front end feel mushy at times.

They add little NVH, are a bit harsher over bumps and cracks, and you can feel them in the steering under cornering loads - that's actually something I like. It reminds you you're driving something special.

[Irhase46m3]

Thanks everyone for their input!

[Tbonem3]

I like the idea of the 034 motorsport front pair of arms with stiffer rubber. Noted for future refresh.