DIY: Suspension Parts/Setup/Tools

[BMWE46M3]

I’m reaching out to my fellow M3 brethren for some advice. I have a 2002 M3 coupe with 74,000 miles with the original suspension components. This car is a daily driver and will not be tracked. I bought it in March 2020. It’s lived in Miami, Dallas, and now Raleigh so it’s been and will be out of a winter corrosive environment.

This fall I plan to install Koni shocks with Eibach springs which lowers the car 0.9"F and 0.6"R. Over the next few weeks I intend on removing the rear subframe to inspect the RACP for cracks and reinforce it if needed. With the subframe out, I plan on replacing the subframe bushings with TMS solid aluminum bushings. I also intend on replacing the RTABs with new OEM style with limiters. Up in front I plan to replace the control arms and tie rods. I also intend on replacing both front and rear sway bar links with TMS adjustable links to account for the lowered ride height. With all this being said, can you guys please answer the following questions:

• Do I really need adjustable end links in the rear considering I’m only lowering 0.6”? If not, can I go with OEM or will the preloading of the sway bar be an issue? Or should I simply go with OEM from another model such as the E30 which I believe are a bit shorter than the E46.

• Will I need adjustable rear camber arms or will there be enough adjustment in the OEM arms to align the car within specs?

• Will I need front adjustable camber/caster plates or can I use new OEM upper strut mounts – again I want the alignment to be within specs.

• Just about everyone offers limiters for the RTABs - mostly differing in material. Do you guys have any brand recommendations?

• Does anyone have the RTAB tool they’d be interested in selling or renting out?

• Does anyone have the subframe bushing tool they’d be interested in selling or renting out?

Thanks for your help…

[Obioban]

-Stock rear end links will be fine. AFAIK there isn't an aftermarket option that works with the the rear stock sway-- I ended up fabbing my own to get adjustability, to dial out preload.
-with the sunframe out, you should really install a vincebar and plates. You're 80% done the job already, and you'll regret it if you don't.
-at .6" of rear drop, I suspect you'll be able to get within spec still, without adjustable rear lower arms.
-get monoball RTABs instead of limiters. If you're hung up on limiters, all the brands are the same.
-you can reuse your stock upper strut mounts. They last a LONG time. Either way, you don't need camber plates (if you're going to track you should get them, as they'll save you a ton of money in tire wear).
-don't forget about the rear control arm (upper and lower) outer ball joints. 4 total.

[BMWE46M3]

Thanks for the reply. What monoball RTABs do you recommend?

[Obioban]

Thanks for the reply. What monoball RTABs do you recommend?

SDW, from FCP.

[FBloggs]

I am using the Koni/Eibach combo.
you don't need adjustable swaybar end links as the lowering is conservative.
I am using shorter E30 M3 front bar end links but most people use the stock pieces.

I bought a car with 83k on it and It took the replacement of pretty much the entire suspension, and bushings to get the car to exhibit that attitude of tenacity that M cars have.
Follow the advice given on the RACP reinforcement while the subframe is out, as it will save you money and add to the degree of improvement you want to feel.

[cobra]

I have read some very negative things about monoball RTABs on street cars. People say that when you hit a sharp edges bump it transmits everything into the car. I personally went new stock bushings from FCP and will just replace them every 20k miles. Good compliance and handles fine.

[Obioban]

I have read some very negative things about monoball RTABs on street cars. People say that when you hit a sharp edges bump it transmits everything into the car. I personally went new stock bushings from FCP and will just replace them every 20k miles. Good compliance and handles fine.

Who said that? Even Dinan sells monoball RTABs, and they're about as civil as parts come :P

More over, it's not true ("People say that when you hit a sharp edges bump it transmits everything into the car").

[oceansize]

I have read some very negative things about monoball RTABs on street cars. People say that when you hit a sharp edges bump it transmits everything into the car. I personally went new stock bushings from FCP and will just replace them every 20k miles. Good compliance and handles fine.

That is a huge huge untruth. I don't know what percentage of forum members here are running monoball RTABS but it is large. One of the best mods I've ever done and the NVH penalty is non-existent unless we are talking a princess and the pea situation lol.

[jet_dogg]

Odd he would rather take the advice of people outside a niche forum instead.

[Cronenberged]

I'm not running monoball RTABs, but when I replace the AKG 95A I have installed now I will be.

[Tbonem3]

I mean, to be fair, you will feel things more, esp hard edges like square bumps or pavement cracks/reflectors. There's no absorption like with rubber or even poly (to a lesser degree). The harshness or firm"ness", not noise or vibration, penalty with spherical isn't any worse than poly, in my experience.

That said, the trade off is huge - no deflection and change in toe, more confidence - no squirm or side stepping.

You can't say there's no trade off though. Rubber will always be more comfortable.

[oceansize]

I mean, to be fair, you will feel things more, esp hard edges like square bumps or pavement cracks/reflectors. There's no absorption like with rubber or even poly (to a lesser degree). The harshness or firm"ness", not noise or vibration, penalty with spherical isn't any worse than poly, in my experience.

That said, the trade off is huge - no deflection and change in toe, more confidence - no squirm or side stepping.

You can't say there's no trade off though. Rubber will always be more comfortable.

Quantify that trade off in a percentage of harshness gained. People will read into your comment and think see it's noticeable but we all know solid RTABS are so superior that the 5% gain in harshness during the 5% of the time you are driving on truly crap roads makes the difference for all intents and purposes non-existent.

[cobra]

Odd he would rather take the advice of people outside a niche forum instead.

The advice was from THIS forum. I found several mentions of it in fact. Many said the pros outweigh the cons but also many are comparing old clapped out stock bushings to monoballs. Fresh OE bushings are pretty good and very comfortable. I admit I have never experienced monoballs so I don't know personally.

For me personally, most of the roads around me are bumpy and broken, so I didn't want to risk it. Same reason I don't lower my car more, it would be impractical as much as I want to do it for looks.

I am sure if you ever track the car or live in an area with smooth roads monoballs are amazing.

[BMWE46M3]

Has anyone had issues with the TMS solid subframe bushings? Just wondering since CMP and TMS both offer solid aluminum bushings for a similar cost but shipping from CMP is another $60. If CMP's are a superior product for reasons I'm not aware of then the shipping cost is certainly justified. Please understand I'm not trying to be frugal but trying to understand the difference. The differences are more apparent with their other products such as their RTABs.

Regarding the monoball RTABs, will they last longer than OEM rubber bushings?

[repoman89]

The advice was from THIS forum. I found several mentions of it in fact. Many said the pros outweigh the cons but also many are comparing old clapped out stock bushings to monoballs. Fresh OE bushings are pretty good and very comfortable. I admit I have never experienced monoballs so I don't know personally.

For me personally, most of the roads around me are bumpy and broken, so I didn't want to risk it. Same reason I don't lower my car more, it would be impractical as much as I want to do it for looks.

I am sure if you ever track the car or live in an area with smooth roads monoballs are amazing.

I installed fresh OE rubber with my vincebar install about 5k miles ago, and switched to Turner monoballs within the last thousand miles / two track days. There was no noticeable difference in NVH after the switch even on garbage New England back roads. The car has the fiancee approval as well with Ohlins, monoballs and fixed back seats. BMW left a lot of room for performance vs comfort in the design of this car.