Mod Update
Powerflex Black Thrust Arm Bushings and revised suspension settings
If you guys read my mod list for my old M3 you know I value suspension above all. I had every bushing replaced with either group n rubber or polyurethane. I love precise feeling suspension and I was hoping that could be achieved with the X5M to some degree. Part of what makes these sav's so crazy is the fact that they can turn better than most cars. Anything that furthers this concept is worth exploring so when my front thrust arm bushings started to go I began exploring aftermarket solutions.
What I found made me extremely excited. No more than 4 months ago Powerflex finally came out with a selection of bushings for the e70 platform. They offer thrust arm and swaybar bushings as well as subframe limiters and rear camber bolts.
As such I went with their thrust arm bushings. They offer them in two types of stiffness; street and race. Since I'm weird I went race. Figured might as well go all out and just change them out later if they were too much for me. The black (race) versions are said to be 295% stiffer than the oem bushings and they definietly feel like it.
Link to their press release:
http://www.powerflex.co.uk/blog/bmw-x5-e70-and-x6-e71
They really transformed the ride for the better. It's firm, but not harsh if that makes sense. I can now feel everything and the suspension movement is much more controlled now. Like there is no more give in the front. Acceleration and braking are crisper in feeling and high speed stability has a more solid feeling.
NVH (noise vibration harshness) wise, there is no increase in noise yet, no vibration increase, and of course there is more harshness. However I don't mind harshness whatsoever so it's not a problem to me. Due notice I'm saying harshness not compliance. The suspension still moves in it's full range of motion; it's just when hitting irregularities in the road it feels more solid now, not as soft and cushioning. Their street version will definietly be more soft in feeling, but I was after precision not comfort. Plus I used my own weird logic that if these were designed for the e70 chassis in general then the street version might only be as stiff as the M version and I wanted to improve the precision and not move laterally.
Here is a link to their UK site that has a deflection chart for the three types of bushings: oem, street, race:
http://www.powerflex.co.uk/road-seri...ush/11462.html
After the success I've had with these bushings I'm definietly going to get the swaybar bushings next. Probably this summer some time. Regarding installation tips, make sure you purchase new ball joint and bushing nuts as they are one time use only. Don't have any install pics as I had my girls with me so I didn't hang around the shop.
Packaging:
The bushings
. They are a two piece design so the only hard part of the install is going to be pressing out the oem bushings:
New nuts and torque specs straight from the dealer:
My shot oem bushings:
Regarding new suspension settings I moved the compression softer a click all around (compression is now a full circle off fully closed) and the rear rebound stiffer a click. Kept the front rebound the same. Had the alignment set at -2 camber all around with -.04 toe on each front corner and -.08 toe on each rear corner. Give it a try as it made the ride much more compliant. I made these changes since I'm mostly highway driving now.
