sway bars - if u have them, please recommend

[bahnstormer]

i think that my next modification will be to change
the sway bars for fatter ones. i'm looking for some
options and recommendations


080.0900.05 G-POWER antiroll bar kit - Sport - GS E34 4Cyl./6Cyl./8Cyl.
Reduction of the sideways overturn by 60 per cent (manufactured of hydroformed steel). No loss of comfort, optimal function in connection with G-POWER progressive sports springs. Complete set front- (Ø27mm) and rear (Ø20mm) axle incl. rubber bushings.

Application: Saloon/Touring

Additionally included in the package: G-POWER assembly instructions, G-POWER lubricant, G-POWER guarantee certificate, G-POWER sticker, TÜV-approval at \"G-POWER Brunsbüttel\" possible


i've found those so far for my 91 535i. i know mtech makes a set too
but i'd imagine those are hard to come by?

also racing dynamics makes some sways too

what do you guys think about these various offerings?

here's what bmwe34.net has to say, but i know that a lot of
people on the board have different opions, and i'd like to hear
them all



Sway bars tie the lower suspension components together accross the front and the back, they affect the car oversteer and understeer. Bigger sway bars improve stability while cornering, the best setting is fully soft for the front and hard for the back.

Stock: Front: 23mm - Rear: 15mm.
Sport suspension: Front: 24mm - Rear: 18mm.
M-Technic suspension/US E34 M5 3.6: Front: 31 35 2 226 333 - 25mm Rear: 33 55 2 226 507 - 18mm
Eibach: Front 26mm - Rear: 13mm. (yes, I called them to confirm)
Racing Dynamics: Front 27mm - Rear: 19mm.

Also there were Nuerburing (BMW's spelling) rear swaybars for the M5 Touring. These were the biggest rear bars ever offered. These may be the perfect complement to the 27mm bar offered by RD as their front rear ratios are highly biased to understeer and these may improve the situation somewhat. Rear 33 55 2 227 416 - 20mm

31 35 2 227 276 $118.00 (m5t front)
31 55 2 226 334 $6.00 ea. (mounts)
33 55 2 227 005 $108.00 (m5t rear, 19mm)
33 55 2 227 006 $4.00 ea. (mounts)
33 55 2 227 416 $124.00 (N'burgring m5t rear, 20mm)
33 55 2 227 240 $4.00 ea. (mounts)

With a 20-25% parts discount offered by several BMW dealers in Roundel, and considering that rubber bushings are available from the factory (much quieter and transmit less vibration), the factory bars are a pretty decent choice without being prohibitively expensive. However, there is a time factor to getting these items as they have to ship from Germany, those ordering the Euro parts will have to be patient...

[John B.]

I ordered the MTech sways through BMA & got them pretty quick. As I recall one was in stock in the U.S. & one came from Europe but it didn't take too long. I liked the idea of sticking with the factory rubber bushings & have been happy with the M sways.

[Martin in Bellevue]

Jeff & I both have the RD sways. Thanks again to Bruno for that group buy. The RD bars are pretty beefy; there is the slightest tire rubbing at full lock, with larger wheels. The bars have some adjustment to them.
Compared to earlier cars, like e28's, the stock e34 front bar is monstrously big already. Maybe next time, I'd try changing the rear bar for that big 20mm m5t bar & keep the front bar stock?

[Johntee540]

I am running the RD bars Front and Rear. The car is set totally neutral. And I am loving life. They are adjustable. I would add RD bars all over again. Made huge difference in tuning out the plow in the turns. - JT

[Robin-535im]

I would recommend adjustable ones, just for the sake of tunability. I think mine are Dinan (Martin, Jeff - do you know?) They're blue, not green, so I think they are either RD USA or Dinan.

Either way, I love them. Sways + 17" tires + Shocks and springs.... woo hoo what a ride!

[bahnstormer]

thanks guys
i'm almost there with the sachs kit and my 17's 235/255
i played with the tire pressures and my car is fairly neutral, up until
120+ and then it'll understeer

so my main reason for sways, is to well, prevent sway =] i've noticed
that in sharp jerks, say to avoid a pot hole or the like the sachs kit
is a little under damped and takes a while to get settled....

so i think i'd do both front and back...

now which RD did u guys buy from? the usa one? or the "real" one in italy?
did u buy through bmpd or what? let me know! =] thanks

[bahnstormer]

Jeff & I both have the RD sways. Thanks again to Bruno for that group buy. The RD bars are pretty beefy; there is the slightest tire rubbing at full lock, with larger wheels. The bars have some adjustment to them.
Compared to earlier cars, like e28's, the stock e34 front bar is monstrously big already. Maybe next time, I'd try changing the rear bar for that big 20mm m5t bar & keep the front bar stock?


the first set that i posted, from g power is exactly that,
a 27mm front and a 20 in the back...what do u think?

another note, the dinan's are 25 front and 19 rear

[Mr Project]

I bought an MTech set from Cacatfish, 25/19 I believe. Current config:

Totally stock suspension (187k, probably not all original, soft but not totally worn-out)
Bruno's rear subframe inserts
15" baskeweaves - 225/60 rear, 215/60 front (PO's fault)

The swaybars made a noticeable difference in body motions during those quick transitions you mentioned. Swerving to miss a pothole-type of motions, correcting for a little power oversteer, those kinds of things. Overall the car rolls less, gives the feeling of faster turn in (less time spent 'taking a set'). I would also say that the overall cornering limit is higher, significantly, even. I would not say at this point that I have less understeer, which was a surprise to me. Mid-corner or even towards corner exit I can put more power down due to the higher limits, but it is actually less likely to oversteer than it was before.

Obviously my staggered tires will add understeer, but I'm speaking in a relative standpoint comparing my current setup to the stock swaybars with the same tires/suspension.

My theory is that overall cornering grip has gone up due to better body control and reduced lateral weight transfer, but the 25/19 combo and the staggered tire factor mean that I still get some understeer, and it's a bit more noticable now due to the higher limits.

Overall the car just feels better, smaller, lighter, and more willing to scoot through a corner rather than wade through it. Make sense? But it did not totally make the car neutral.... the RD bars probably do a better job of that. I'm happy with my purchase...it's a street car and the price was right. I really hope to put a Sach's kit on sometime in the near future and see what that will feel like. Between that and some wheels/tires, this could be a really, really good handling car. :D Well, for weighing 3700 pounds, anyway. :D

[bahnstormer]

great feedback i thank you sir!
however, are the mtech's adjustable?

my 535i weighs around 3500lbs but
factor in the driver, u're right around 3700 yeah

if u get rid of that huge sidewalled 15" u'd get some
better handling too, i bet the 15" sidewalls flex a lot...

what tire pressures do u run? i'd suggest a 35 front 31 rear
to dial in some oversteer for you

[mike wong]

My 91 M5 has 27mm Suspension Techniques front sway bar and the BMW N'ring 20mm rear bar. On a skidpad, the car will understeer at the limit. I am not running staggered tires - 245/40 S-03's at all corners, however I have e-38 M-parallels - 8" front and 9.5" width rear rims.

Note: the N-ring 20mm rear bar has no adjustment holes; the FSB has two and I just changed to the softer of two settings (after skid pad).

Of course, skidpad is only one method of determining how the car handles. Autocross and track require different setups. Learn about trailing throttle oversteer. sign up for driver's schools.

IMO, SB are worthwhile on these heavy cars. Adjustability is great, but everyone I know with bigger bars, sets the rear on hard and front on soft. Which tells me the car could use even a larger rear bar. Wasn't Bruno or someone looking into making a 22mm bar?

In any case, I heartily recommend installing larger SB. any of those you listed will work - get the biggest. I don't think there is any "best" brand, unless you are into color matching...

have fun roadtesting !!!!!

[Mr Project]

My MTechs are not adjustable at all.

Yep, getting rid of the 15's is a priority as soon as the budget allows.

I think I'm running around those pressures....33rear 31front, I think...the main thing was that I didn't want to change the pressures right away so I could get a good feel for the difference the swaybars made on their own. Once it warms up a bit, I'll play around with pressures again. It's pretty rare this time of year to get a clean bit of road to enjoy driving on anyway. :)

[Paul in NZ]

my standard mtech stays pretty flat through the turns,i wouldnt say it understeers at all,the turn in is not always super sharp tho

[Alan_525i]

I have the RDs. Very happy with them except having to replace the rear links at 25K miles...$100. I haven't heard of anyone else having to do this so maybe this was an isolated occurence.

[Robin-535im]

i played with the tire pressures and my car is fairly neutral, up until
120+ and then it'll understeer
a

[Martin in Bellevue]

I've made the greaseing of the rear links part of the usual under-car chores. They get noisy, with all the rain here.


I have the RDs. Very happy with them except having to replace the rear links at 25K miles...$100. I haven't heard of anyone else having to do this so maybe this was an isolated occurence.

[Mobius]

I've got a pair of Dinan bars - though being lowered and running hilariously wide rubber as it is, they don't add much to the handling. What I really needed them for was the ability to tune out some of the understeer I was experiencing; and they did an excellent job of that. The Dinan bars are 25mm in the front and 19mm in the rear.

Plus I get to say I have Dinan sway bars. :)

For kicks; short video of me driving like a wuss at an autocross a while back: http://home.comcast.net/~rjchristie2/SA/535i/mobiusgood.wmv - Look ma, body roll?

[liquidtiger720]

Those are some huge shoes. 19in mobius?

How would changing the ration between front and rear affect understeer? Like, if you were to increase the rear withougt increasing the front- would cause more or less understeer. etc.

I think I am settled on 27mm front and 20mm rears, but I am curious on how the ratios change the amount of understeer. etc.

[Mobius]

Those are some huge shoes. 19in mobius?

How would changing the ration between front and rear affect understeer? Like, if you were to increase the rear withougt increasing the front- would cause more or less understeer. etc. 18" :)

Stiffen the front (either with a bigger bar, or by moving the end links IN) or soften the rear to increase understeer (decrease oversteer).

Soften the front (either with a smaller bar, or by moving the end links OUT) or stiffen the rear to increase oversteer (decrease understeer).

http://rogerkrausracing.com/overundr.html :)

[Johntee540]

Since RD in the USA is right down the street from me and across the street from my indy - I bought from RD America. - JT

[bahnstormer]

nice vid mobius, very clean lines, no tire squeal (squeel?)
but i think that u may not have enough suspension travel
it looks like u're more for show anyway, with the 18's and
such =] glad to see u're having fun though! =]

ya i emailed bav auto



Martin,
We can special order that kit for you for $699.95. It would take 8 to 12 weeks to get.

Or you could get the Racing Dynamics kit that we have in stock.


Racing Dynamics Swaybar Kit - 27mm Front 19mm Rear - Adjustable
Upgrade your confidence in fast cornering. A Racing Dynamics front and rear sway bar kit ... more info...
Part # : 196 81 34 010 $ 449.95

Patrick Dowling
Bavarian Autosport
275 Constitution Avenue
Portsmouth NH 03801
800.535.2002
603.427.2002
Shop our online store!
http://www.bavauto.com


that first price is in reagard to the g power kit, 27 front 20 rear....
i don't think i can swing the cost nor the wait time....

what is the latest word about bruno making a rear 22 bar?

any one else hear something liek that?

[bahnstormer]

quick bump to add on

after talking with AlanS about his sway's (RD)
he mentioned that the rear links wear out
in 15,000 miles...

and for a $100 part, when the entire setup cost
me $400 i think that is stupid...

UUC supposedly has a fix for this, anyone try it
yet?>

[Mobius]

My Dinan bars use the stock rear links (which would be nearly impossible to wear out by design) - with a bolt through the bottom where the stock bar ends stuck through.

I don't see the point of using such a complex heim-joint link to connect the rear sway bar. By eliminating the small amount of rubber in the stock joint you gain a tiny bit of stiffness, sure - but..

Heim joints are for track cars. They're strong and they're precise, but they're open to the elements and aren't long lived if they aren't taken care of.

Is there not a way to bolt to the original end links with the RD bar?

[mpower06]

Does any one know what type of links front and rear are used on the Whiteline, Susp. Techniques, Eibach or G-power sway bar kits - rubber dogbone, Heim joint, etc.? Do all of them even come with links? Are all of these bars adjustable? Just curious as this would obviously play a role in the buying decision? Thanks. :)