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My RD sway bar story, Part 2

5K views 26 replies 15 participants last post by  psmportland 
#1 ·
Well, for those of u that know me, I broke my RD sway a year ago and it was replaced by RD sports owner...He explained to me that I originally received a bar that's only used in the beginning of a batch being made and that it should have never been sold to the public..so I said **** happens and moved on because they sent me a new bar free of charge...after talking to a few other guys on here who broke theirs, I learned that water and rust may be a problem getting inside the bar. With the new bar I decided to use sealant around all welds to completely seal the bar from water...well, a few days ago the second bar broke at 5mph entering a driveway at my work....the bar broke in the same place as last time which has made me come to the conclusion that there's something wrong with the way these things are made...I strongly urge anyone that owns one of these bars front or rear to return them to the place u got them from, it's only a matter of time before they break like mine did......
 
#2 ·
I'm sorry to hear that. I keep going back and forth whether I'm going to get them or not. It doesn't help that for every good experience I hear about, there is another situation reported that is the opposite.

You going to switch over to another solution or go back stock? As I see it there are two other options. One is Dinan front/rear and the other is M6 comp bar front and Dinan rear. According to calculations on another thread here the M6 comp/Dinan combo should get the percentages the Rd solution provided.
 
#3 ·
Damn Paul, sorry to hear that, again! What a nightmare of a stupid sway bar. Hope you take further action and get your money back plus labor costs back. What a waste of time and money. Ain't no one got time for that sh*t.

Dan
 
#5 ·
I've wondered about this as well Hasan, having a lot of stiffness on the sways reduces body roll and feels good, but prevents some of the weight transfer needed to fully load the outer cornering tire to achieve maximum mechanical grip.

I think you could probably get close to the RD Sport for stiffness though with the M6 competition package 29mm OEM sway and Dinan Roll Control system if one were dead set on it. All the M5 and M6 front sways are interchangeable. This is my plan for my Touring as the OEM M5 E61 sway is 28mm (shared with the E64).
 
#6 ·
Hi Jim!

What you are saying makes complete sense. The RD sways worked somewhat fine as long as I had OEM suspension. But once, I switched to CKS suspension with a high spring rate, I had a lot of understeer with the RDs. So now I'm back to stock sway bars and the car feels much better.

I have a few friends who race semi professionally, and they disconnect the sways in rain or on tight auto x circuits. Especially if the auto x circuit is bumpy.
 
#7 ·
Dammit, OP. Did you not read the thread where we decided everything was going to be o.k.?

So sorry to hear that, very frustrating.....


The words bump and driveway caught my attention. The only times I *feel or hear* anything unusual is going up or down an incline (ie. driveway ) with the wheels turned. It seems to be a binding, semi grinding noise followed by a pop that might be pressure release. One of those noises that makes you cringe. I am on RD sport with Gas Mono Balls, and stock suspension with stock size Mich. tires. It is definitely related.

Maybe we can get Randy to chime in here, as he has gone to an adjustable end link from Bimmerworld (for similar reasons, I think). It looks like almost all BMW platforms use these way more than is discussed here.

Maybe the stiffer OEM bars with the ADJ end links are a viable performance option. I can also see how the RD Sports might be a bit much to allow full suspension upgrade to keep the wheel on the ground. Those Intrax with Roll Control sound so bad as.s you may not even need sways, M5guy!

BUT, what do you think Woody? Your car looks very neutral and I thought you had tried both ways with the CKS/swifts?

I got the B16 one click from ordering. FUC.... :pedro:


What a joy. Eliminate and reintroduce understeer for about $5K.


The RD sport and GAS balls paired with stock suspension are a HUGE improvement. There are certain circumstances where I could induce power understeer (read plow) stock, that I can now take at speed. The handling is superlative for a basically stock car, esp. paired with proper tires.


Here is the table that we were using on the "OEM sway bar option" thread


Front:
26.5mm - E60 M5 Stock - 31352283070
28 mm - E61 / E63 - 31352282790
29 mm - E61 Competition / E64 - 31352283123

Rear:
18 mm - E60 / E63 - 33552283072
19 mm - E61 Competition - 33552283908
20 mm - E61/E64 - 33552283036
 
#21 ·
Sh!t ive been tracking down a popping sound in my front suspension for the better part of 6mos....ive literally replaced everything:

- upper control arms w/ new bushings
- lower control arms w/ new bushings
- say bay end links
- installed coilovers

car handles like a dream but the sound is still there. I have RD sway bars....i wonder if i should take it off & inspect it...
 
#8 ·
Sorry to hear this happening again Paul, I always thought after the first one snapped that there was a design flaw.
 
#9 ·
Texasgrego, thanks for the info, I already talked to Randy about my bar be our first bars broke around the same time in the same place....I've been looking into other options and I'm wondering if the Dinan Frc with that m6 comp bar you guys are talking about would be a nice setup or too much...?? I looked up the H and R one yesterday and it's only 27mm which I wouldn't think would make much over stock like the RD sport 30mm...gotta do research on the m6 comp bar..where can u source one of those bars, the dealership I figure....??

Dan, I'm done with these RD bars...I think I'm gonna yank off the rear too because I don't wanna keep bugging Joe at Trinity so many times...Joes been a serious stand up dude since he's the only selling these bars now I believe...he told me he's gonna have a serious talk with Frederico about the cast and production of these bars...I honestly don't blame Randy Wei for not wanting to put his back on..

Stay tuned.....
 
#11 ·
I have the full Dinan setup with no issues thus far.
 
#14 ·
@Sfbimmerman sorry to hear the RDs siht the bed again on you. Randy txted the pics of your snapped sways last week...WTF! He and I were talking about your sways last night at dinner.

I guess I'm one of the lucky ones with my original RDs. I have nailed a curb/sewage drainage ditch, at speed with zero damage to my sways. I thought, for sure, my sway would have snapped. I've launched the Bustop and Phill Hill at Buttonwillow, and nothing...

I got mine from Trinity (Joe) as well. Hands down, Joe is stand up.

As far as an alternative...I don't know. Dinan FRC didn't do it for me. Going in a straight line FRCs worked great, but at the track making turns, my sidewalls hated them. My car is set up very neutral. The only understeer I'm getting is under heavy trail braking on tight AutoX courses -- much of which is due to my upgraded 30/50 diff.

If I had to replace mine tomorrow, i would try the OEM Competition m6 and aggressive camber plates. It's sad to see a company with a (at one time) great product, spiral miserably with current execution and follow through.
 
#19 ·
Sorry, haven't been on the forums recently. Was wondering when Paul was going to post a thread about his second snapped RDSport front sway bar.

I recently changed to the 11" Bimmerworld Adjustable End Links, but I also am running the stock sway bar with Dinan FRC, not the RDSport sway bar. I was getting a knocking sound from my sway bar when going over bumps after switching to the Bilstein B16 EDC Coilovers and adjustable end links were needed to resolved that annoyance/problem.

I do have a replacement RDSport Sway Bar after my first one snapped, but I didn't throw it on since I didn't want to have to deal with the new one snapping as well. I actually do have plans to have a friend test it with tensile strength against a stock M5 sway bar (I'll need to get one from Jim if he has any left). Just haven't gotten around to it.

The RDSport setup was definitely better for around the track, but for those who don't track their car or go on too many twisty spirited drive then I think the Dinan FRC setup will suffice. It's definitely an upgrade over stock, just not as much as one would like for more serious driving.

FYI - here is Paul's first thread on his RDSport sway bar snapping where a few of us also chimed in with our stories and build dates.

http://www.m5board.com/vbulletin/e60-m5-e61-m5-touring-discussion/432386-rd-sway-bar-questions.html
 
#22 ·
Picture for reference



This setup is literally so much "tighter" than stock it is amazing. Definitely exerting more force on the tension strut than the original hydrobushings under load.




The Dinan FRC simply makes the OEM bar shorter (you drill the hole) and offers a bracket to mount it. Looks like the end link would go before the bar here. The bar maybe not stout enough for the new position, thus the rollover on the sidewalls Woody described.




I think the conservative common sense approarch might be the end links Randy is using and the stiffest OEM bar.



I will hang the car and work the susp. with the wheel turned when its on the rack ltw.
Not a good idea for me to hook up a camera or drive without an underpan @Clyde. A buster would come up for sure...:M5launch:, and apparently I easily forget electronic and other attachments:rofl:in my excitement lol

Any bars broken on a car that was not lowered...???
 
#24 ·
IDK

I only see 28mm bushings even though they are listed under the 29mm bar for all of the vehicles that use 29mm on RealOEM????

I'm sure it would work, but SQUEAKKKKING is already an issue.
Whats your suspension, and are you going to utilize the end links per Randy to adjust the pre load?


Check your PM's Sfbimmerman.
 
#27 ·
My first time here in a year or so...after searching for a topic I assumed would be nonexistent...

But it wasn't.
Backing in my driveway with...wait for it...a load of groceries.
slight bump in the driveway, so I do it fast so I don't have to abuse the clutch, as you all do with SMG...and a big clunk and done. broken RD sport Sway. I see stock ones and the above mods coming.
 
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