Several months ago I bought the front sway bar off of an E34 M5. It is only 1mm thicker than the original sway bar, but I was told by reputable people that it will feel firmer than before.
In the meantime I searched for better rear sway bars and came across a Racing Dynamics adjustible rear sway bar brand new for $100 on ebay, so I snatched it. I have Racing Dynamics sway bars on my E28 and they made a world of difference, so I feel good about the purchase.
I have the following questions:
-Now that I have both sets, I am ready to put them on the car. Considering that both sway bars are larger, especially up front, do I use the same torque settings as recommended by Bently's or add a few lbs. of extra torque?
-The rear sway bar links are adjustable, but turn by a screw so I guess I'll have to count how many times I've turned it to have them even?
-How does the adjustment effect the ride? Which way for sportier and which way do I turn for comfort.
- Will I need to re-enforce any of the brackets up front or at rear? This is 100% necesarry on the E28 and wondered wether the same was so for the E34's.
- The rear sway bar has urethane bushings, do they give too harsh of a ride and am I better off using the rubber ones that are already there?
I also found a front strut bar which I will pick up soon, so I'm really looking forward to how this car is going to handle.
Thanks
Fred/Houton
1994 540ia

I don't think the bushings will make the ride harsher. Some will even use delrin bushings which are even stiffer that urethane and reduce flex even more.

I have never heard of reinforcing the brackets either. As far as torque settings the bentley recommended values should be appropriate. Over torquing bolts may weaken them.

Someone else can answer the rest :)

The more length you have on the adjustable sway bars, the more stiff it should feel.

-Now that I have both sets, I am ready to put them on the car. Considering that both sway bars are larger, especially up front, do I use the same torque settings as recommended by Bently's or add a few lbs. of extra torque?

No reason to use any more torque than stock on the bolts IMO.


-The rear sway bar links are adjustable, but turn by a screw so I guess I'll have to count how many times I've turned it to have them even?
-How does the adjustment effect the ride? Which way for sportier and which way do I turn for comfort.

Haven't seen an RD bar but this doesn't make much sense to me. If you're only adjusting the length of the end links, that's not going to make the swaybar any stiffer or softer. Adjustable bars let you put the links closer to the 90-degree 'bend' or further from it, changing the leverage that the bar has against the suspension.


- Will I need to re-enforce any of the brackets up front or at rear? This is 100% necesarry on the E28 and wondered wether the same was so for the E34's.

Nope, E34s are fine.


- The rear sway bar has urethane bushings, do they give too harsh of a ride and am I better off using the rubber ones that are already there?


Nope, use the urethane bushings, not only for the extra stiffness but also for the fact that the rubber bushings have too small of an inside diameter for your beefy new bar. You'll have a terrible time getting the brackets back on with the old bushings.

Ride quality impact is minimal with big bars unless you are hitting a one-wheel bump or a strange offset pavement undulation. Straight-line ride quality is mostly unaffected, which makes big bars a great upgrade IMO.

Thanks for not posting in all caps.

Thanks guys, I really appreciate those answers! I'll report on the ride when I am finished.
Fred/Houston

I installed mine a few days ago - You'll Love Yours!!

Oh, and make sure you lube them up when installing them! I forgot that key step, so I have to re-do the whole thing now.

srent the RD sways adjustable?
What settings would you set it to?

Yeah, the front bar has 3 points, and 2 for the rear. For me, the links are set to the spot closest to the bend in the bar.

Here's a quick diagram-

Yeah, the front bar has 3 points, and 2 for the rear. For me, the links are set to the spot closest to the bend in the bar.

Here's a quick diagram-
And is that a good set up?
what do each of those settings do?

Well, I figured that having it set closest to the bend, theres less leverage, and less twist, so the bar is stiffer. If you were on the outer-most setting, the bar would have more metal to twist, and so it would be softer.

Well, I figured that having it set closest to the bend, theres less leverage, and less twist, so the bar is stiffer. If you were on the outer-most setting, the bar would have more metal to twist, and so it would be softer.

i concur. further from the bar should be softer, more leverage.

Well, I figured that having it set closest to the bend, theres less leverage, and less twist, so the bar is stiffer. If you were on the outer-most setting, the bar would have more metal to twist, and so it would be softer.

Thanks for pointing that out. I also have them on my E28 and I actually felt the difference when I installed them & just backed out my driveway.
I have them on the center hole of the rear bars on my E28 so I think I'll go stiffer to the bend on that car as well.
...and thanks for the heads up on the lube. I had totally forgotten about that!
Fred/Houston

No problem! That's what I'm here for. Now if I could just lube mine up to get it right. (not just the sway bar....)

i have both mine set on the middle hole...ill make mine stiffer and see if i notice any difference

Well, I figured that having it set closest to the bend, theres less leverage, and less twist, so the bar is stiffer. If you were on the outer-most setting, the bar would have more metal to twist, and so it would be softer.
ahh yes it makes sense now thanks abunch