Questions finalizing suspension refresh

[Subfra///Me]

04 M3 coupe with 93k miles. Car is pretty much stock. Used as a fun/weekend car with light track/autocross use. Goals are OEM+. Improve ride and handling over stock without causing too much additional NVH.

New parts going on;

Koni Yellows (TCK spec rears)
Dinan Springs

Front
Turner street camber plates
Turner monoball front control arm bushings
OE control arms
OE tire rods
OE end links
OE sway bar bushings
OE spring shims
OE strut mount gaskets

Rear
Meyle HD shock mount kit with reinforcement plate
Turner monoball rear trailing arm bushings
OE rear sway bar bushings

Any issues with my goals and products listed?

Anything I should add to this list?

Do I need to replace bumpstops?

Do I need adjustable sway bar links with the Dinan springs or is the drop insignificant?

Looking to reduce roll slightly. What are the best front roll bar options? CSL, Hotchkis? Leave rear stock?

[bmwfnatic]

Seems like a decent list for an OEM+ street car / overall just a refresh.

The only odd one in the list is the Turner FCABs, the reviews on those on this forum aren't anything to write home about.
Only a few members have used them without issues and I recall a lot of people shipping them back for noise and knocking, don't think that ever got solved.

I would replace bump stops, after 18 years they can become brittle and crumble when you touch them.

As for sway bars, I doubt that you'll feel a difference with CSL bars, they are simply made for a different setup car with different weight and thus different spring rates to meet the engineer's target data.
Simply slapping them onto a pretty much stock M3 without changing anything else doesn't seem like a great idea to me.

You can of course go down the rabbit hole of the whole FCM spreadsheet, but based on your parts list this seems a bit far-fetched.

[Tbonem3]

Yes replace bump stops. I would get bilstein b6 over junk konis if performance is of any concern.

Don't need shorter end links. CSL bar is good, hotchlis is better. Both hollow, but hotchkis has adjustability. I would put it in the middle. No need to get a rear bar.

Don't bother with camber plates if you're sticking with konis. Just an increase in nhv and you don't need the extra 5/8" of travel. Get them if you go with B6s.

Don't bother with TMS monoball fcabs. They're junk. They feel like junk. Go oe rubber for that classic bmw road feel.

[cobra]

Koni Yellows (TCK spec rears)
Dinan Springs I would stick with stock springs or shim the Dinan fronts

Front
Turner street camber plates Not needed
Turner monoball front control arm bushings Go stock
OE control arms Only needed if your ball joints are clapped out. Mine are still tight at 100k miles. You can easily test the ball joints.
OE tire rods Same as above
OE end links Same as above
OE sway bar bushings Same as above
OE spring shims Same as above
OE strut mount gaskets What is a strut mount gasket?

Rear
Meyle HD shock mount kit with reinforcement plate Meyle is good, but only need to replace if yours are worn out.
Turner monoball rear trailing arm bushings I've heard good things, but potentially added harshness on square edge bumps
OE rear sway bar bushings Not needed probably

Any issues with my goals and products listed?

Anything I should add to this list?

Do I need to replace bumpstops? I would

Do I need adjustable sway bar links with the Dinan springs or is the drop insignificant? The drop doesn't affect the swaybar end links since they move together.

Looking to reduce roll slightly. What are the best front roll bar options? CSL, Hotchkis? Leave rear stock? Stock

Honestly you probably don't need to replace most of this stuff. I was surprised to see most of my stock hardware in excellent shape at 100k miles. Do the bushings, inspect the other parts. Take the extra money and invest in a proper suspension kit and you'll notice way more benefits. For OE+ take a look at those B6's.

[Bry5on]

If you have square tires, consider a bigger front bar. Otherwise I agree with everyone above, except that the Dinan springs do need extra travel (either camber plates or shims). I shimmed mine 1/2” up and am now also adding camber plates solely for the additional travel.

[Zack]

Check out RTAB limiters. Cheap and easy way to help for more rear end stability.

[Tbonem3]

If you have square tires, consider a bigger front bar.

Why?

[Bry5on]

Why?

Ultimately you’re balancing front/rear grip with roll stiffness to achieve either over or understeer balance. If you’ve got staggered tires, you have more rear grip available (relatively) than front, so you’ll want your roll stiffness to be biased a bit to the rear to maximize grip of all of your tires. If you’re square, you can achieve this balance by 1) spring rate change (stiffer front, or softer rear) or 2) roll bar change (stiffer front, or softer rear)

My personal preference is to 1) choose ride frequency/stiffness, then 2) choose front/rear spring rates based on the speed you expect to optimize suspension settling for (my personal preference is 60mph), then 3) set overall roll stiffness and balance by choosing front/rear roll bars. Since he’s selected Dinan or stock springs, he’ll be starting at step 3.

[Subfra///Me]

Appreciate all of the feedback.

The opinions on the Turner monoball fcab's surprise me. I thought most people here liked them?? However, it's been a while since I've been on this site, so seems like that changed. I don't want to deal with any of the symptoms you all have mentioned.

I already have the Koni's, Dinan springs, Turner street plates and Turner monoball fcab's on hand, but that's not a big deal. Bought all of those a while back and just now getting to the rest of my list. I'd rather get the right products for what I'm trying to accomplish, so the Turner FCAB's may end up in the classified section.

So, BMW fcab's or is there a Meyle HD version that's worth looking into?

Will also grab some new bumpstops.

I've read up some on FCM and flat ride, but it's a little overwhelming. I'm not wanting to go down the coilover rabbit hole or cut bumpstops or anything like that. Honestly, I was only considering the B12 kit, B6 shocks/struts or the Koni/Dinan combo I already have on hand. I think remember Obi saying something like the Koni/dinan and plug and play and ride really well, B12 you need the camber plates to get full travel and may have to cut the stops as well. I don't remember much about the B6 shocks, but I will read up on them. Are they best paired with the stock springs?.

Also, have there been as many complaints with the Turner monoball RTAB's? If I don't go that route are the best still BMW with limiters for a road car?

[cobra]

Appreciate all of the feedback.

The opinions on the Turner monoball fcab's surprise me. I thought most people here liked them?? However, it's been a while since I've been on this site, so seems like that changed. I don't want to deal with any of the symptoms you all have mentioned.

I already have the Koni's, Dinan springs, Turner street plates and Turner monoball fcab's on hand, but that's not a big deal. Bought all of those a while back and just now getting to the rest of my list. I'd rather get the right products for what I'm trying to accomplish, so the Turner FCAB's may end up in the classified section.

So, BMW fcab's or is there a Meyle HD version that's worth looking into?

Will also grab some new bumpstops.

I've read up some on FCM and flat ride, but it's a little overwhelming. I'm not wanting to go down the coilover rabbit hole or cut bumpstops or anything like that. Honestly, I was only considering the B12 kit, B6 shocks/struts or the Koni/Dinan combo I already have on hand. I think remember Obi saying something like the Koni/dinan and plug and play and ride really well, B12 you need the camber plates to get full travel and may have to cut the stops as well. I don't remember much about the B6 shocks, but I will read up on them. Are they best paired with the stock springs?.

Also, have there been as many complaints with the Turner monoball RTAB's? If I don't go that route are the best still BMW with limiters for a road car?

Some people like the sharpness monoball FCABs provide, but it will transmit more noise to the cabin since you're eliminating all compliance. The stock FCABs get a bad name because the non-M E46 has flimsy hollowed-out bushings that get clapped out quick. The M3 bushings are solid rubber and hold up much better. The passenger side goes bad because of the exhaust heat causes the rubber to harden up. In fact, when I refreshed my M3 the ride actually got softer because the new rubber was softer than the old hardened stuff. I would just stick with those.

You can pair B6's with Dinan springs, but they are designed for stock height from what I've read.

[Subfra///Me]

Some people like the sharpness monoball FCABs provide, but it will transmit more noise to the cabin since you're eliminating all compliance. The stock FCABs get a bad name because the non-M E46 has flimsy hollowed-out bushings that get clapped out quick. The M3 bushings are solid rubber and hold up much better. The passenger side goes bad because of the exhaust heat causes the rubber to harden up. In fact, when I refreshed my M3 the ride actually got softer because the new rubber was softer than the old hardened stuff. I would just stick with those.

You can pair B6's with Dinan springs, but they are designed for stock height from what I've read.

Thanks for the info. I dont want to add any significant NVH for what I use the car for, so I won't be using the turner monoballs.

What about monoballs for the rtab? Any significant NVH with that application?

Edit: sorry I see you addressed the monoball rtab in a previous post.

[cobra]

Thanks for the info. I dont want to add any significant NVH for what I use the car for, so I won't be using the turner monoballs.

What about monoballs for the rtab? Any significant NVH with that application?

Can't comment from personal experience.

But if if you think about it, when you hit a bump the force wants to push the wheel rearwards and upwards. Normally the shock handles the upwards part as the whole rear suspension system rotates up. Meanwhile the only thing to handle the rearward part is compliance in the bushing. So if you remove that compliance, you are likely to feel a harshness when you drive over something that causes a rearward force - such as a road reflector, or broken sharp-edged pavement. People who have really good roads don't complain at all, but others find them unbearable and have gone back to rubber bushings.

I purchased the limiters but I didn't like how tight they fit, it seems like they would cause binding because the arm needs to be able to rotate freely (something a spherical is very good at). So I am just running stock bushings. You can feel them squirm a little during hard 1-2 shifts but I don't notice most of the time.

[Cubieman]

Just installed Turner RTABs along with solid SF bushes and I cannot say I notice anymore NVH than before.

The PO did have some type of poly RTABs before that I removed so I cannot compare to stock but I am picky about that sort of thing for a street car and cannot say I hear/feel anything out of the norm.

[Subfra///Me]

Thanks guys.

I live in the south. Roads in my area are pretty smooth in general, so the monoball rtab's may be a good option. Will do some more research on that vs stock. With and without limiters.

I don't like reading all of the complaints on the monoball fcab's, so they are out. Its not a track car. Thanks to all for bringing it to my attention.

[bmwfnatic]

Yeah, monoball RTABs are a no-brainer, even if the idea is to keep it stock-ish.
For me, purely because installing the original rubber ones is a PITA (Torque procedure to eliminate preload at normal ride height, I've done it, trust me you don't want to).

Also on another note, not sure if you are aware but B12 = B6, they are the same thing.
B12 is just a marketing name for a kit of B6's paired with Eibach lowering springs, however they made it sound like it is another shock higher up on the shock-tier.