Sensitivity to Wheel Spacers

[3002 tii]

I've run spacers on numerous cars including all my past BMW's but I'm surprised how sensitive the M is to spacers. I recently installed a set of budget brand spacers (same one I used on my Z4 3.0si and e90 328xi) but I felt noticeable shimmy from the steering at 70mph. Thought maybe a wheel weight had gotten knocked off so got all 4 factory wheels & tires rebalanced but that barely made a difference.

Figured maybe the M requires only the "best" so I purchased a premium brand this time around. With regards to install, I'm always meticulous too... wire brush to the face/lip of the hubs, wipe everything down with brake cleaner. Very thin layer of antisieze on inner lip of spacer. While wheel is still off the ground, make sure spacer sitting entirely flat against hub, wheel is centered with hub and then hand tighten the bolts. Put the jack down and torque everthing to 90ft-lb in star pattern.

Final verdict: With new spacers, majority of steering vibration is gone but still slightly noticeable at 70mph. I would say 10% still present but really shocked that it wasn't fully eliminated. Anyone else have this issue?

FYI both spacers (budget and premium brands) were very tight on the hubs, no play whatsoever. At this point I can't tell if it's STILL the spacers or the spacers are just exacerbating a different underlying issue. But with the 2nd rebalance, not sure what else would cause this. Also the M received fresh alignment few weeks ago with the install of my GC school kit (coilovers, camber plates and new oe FCABs). Vibration does NOT occur during braking so it's not the rotors neither.

Only thing I can think of is previous owner didn't drive the car much so maybe it sat for a while and tires developed flat spots? But wouldn't that come up during a balancing test? And could that contribute to a steering vibration at higher speeds?

[racerbruce]

Originally Posted by 3002 tii

I've run spacers on numerous cars including all my past BMW's but I'm surprised how sensitive the M is to spacers. I recently installed a set of budget brand spacers (same one I used on my Z4 3.0si and e90 328xi) but I felt noticeable shimmy from the steering at 70mph. Thought maybe a wheel weight had gotten knocked off so got all 4 factory wheels & tires rebalanced but that barely made a difference.

Figured maybe the M requires only the "best" so I purchased a premium brand this time around. With regards to install, I'm always meticulous too... wire brush to the face/lip of the hubs, wipe everything down with brake cleaner. Very thin layer of antisieze on inner lip of spacer. While wheel is still off the ground, make sure spacer sitting entirely flat against hub, wheel is centered with hub and then hand tighten the bolts. Put the jack down and torque everthing to 90ft-lb in star pattern.

Final verdict: With new spacers, majority of steering vibration is gone but still slightly noticeable at 70mph. I would say 10% still present but really shocked that it wasn't fully eliminated. Anyone else have this issue?

FYI both spacers (budget and premium brands) were very tight on the hubs, no play whatsoever. At this point I can't tell if it's STILL the spacers or the spacers are just exacerbating a different underlying issue. But with the 2nd rebalance, not sure what else would cause this. Also the M received fresh alignment few weeks ago with the install of my GC school kit (coilovers, camber plates and new oe FCABs). Vibration does NOT occur during braking so it's not the rotors neither.

Only thing I can think of is previous owner didn't drive the car much so maybe it sat for a while and tires developed flat spots? But wouldn't that come up during a balancing test? And could that contribute to a steering vibration at higher speeds?

Greetings 3002 tii,
When I purchased OZ Ultraleggera rims from Tire Rack, they included 20 MM spacers (rear only) and longer wheel bolts as part of the purchase. I have not experienced any vibration issues with this application.

[The HACK]

That’s been my experience as well. The front end on the Z4 M is very sensitive to spacers. Not offset, SPACERS. First thing I noticed after installing the RacingBrake front calipers, since it required a 5mm spacer to clear the spokes, was the increase in vibration.

I’ve noticed that thicker spacers, like the 18mm I’m using for the Apex wheels, aren’t as noticeable. But 5-8mm spacers caused a vibration at highway speeds. I’ve managed to minimize it by keeping the contact area clean but have never been able to complete eliminate it and have just sort of “lived” with it, for what it’s worth. Since the Apex wheels are only installed for track events, the slight vibration at speed doesn’t bother me.

Running a squared rear wheels up front does not require spacers for me and that’s the normal “street” setup now.

[3002 tii]

Originally Posted by racerbruce

Greetings 3002 tii,
When I purchased OZ Ultraleggera rims from Tire Rack, they included 20 MM spacers (rear only) and longer wheel bolts as part of the purchase. I have not experienced any vibration issues with this application.

Yea, I think it's just the fronts that are the issue. Rears seem like they'd be fine...

Originally Posted by The HACK

That’s been my experience as well. The front end on the Z4 M is very sensitive to spacers. Not offset, SPACERS. First thing I noticed after installing the RacingBrake front calipers, since it required a 5mm spacer to clear the spokes, was the increase in vibration.

I’ve noticed that thicker spacers, like the 18mm I’m using for the Apex wheels, aren’t as noticeable. But 5-8mm spacers caused a vibration at highway speeds. I’ve managed to minimize it by keeping the contact area clean but have never been able to complete eliminate it and have just sort of “lived” with it, for what it’s worth. Since the Apex wheels are only installed for track events, the slight vibration at speed doesn’t bother me.

Running a squared rear wheels up front does not require spacers for me and that’s the normal “street” setup now.

I've only used spacers in the past out of necessity but with the M, didn't want to go overboard with the mods and buy extra sets of wheels. Plus the factory staggered setup did surprisingly well at my last track event. It's just with the added camber, they do look really tucked in so the superficial side of me thought they could benefit from 15's up front (and even those didn't bring them out fully).

Perhaps 12 isn't thick enough 'drown out' the slightest imbalances... Like I said it's way better than before and I can definitely live with it. Just confused more than anything that the M's front end is so sensitive.

[Westersund]

I use 5 mm on all corners on mine, never had any problems. H&R spacers.

[deemo319]

I have had a shimmy in the 80-90 mph range on the highway.

Running 20mm on all four corners (non-m) but I don't recall if I have driven at those speeds since we installed them.

My vibration is on the passenger side rear. This thread actually reminded me to revisit this issue. I hope you figure it out soon.

[Mirko]

I didnt notice any vibration or issues running 12m spacers up front on stock rims to get around the BBK.

[kaybat]

yes, my M is the same way, and it's only at highway speeds. I had a 2.5i e85 before this, and never had the problem. Once i torqued the studs evenly, it seemed to go away. Every once in a while i get a tiny shimmy, but it's tolerable.(3mm all the way around)

[mmm-five]

I've got 10mm H&R hubcentric ones on the front of mine (to clear Porsche Brembos), and I've not noticed anything at 140mph+.

But that could just be my fat fingers/ass absorbing everything

[RobMCoupe]

Originally Posted by The HACK

That’s been my experience as well. The front end on the Z4 M is very sensitive to spacers. Not offset, SPACERS. First thing I noticed after installing the RacingBrake front calipers, since it required a 5mm spacer to clear the spokes, was the increase in vibration.

I’ve noticed that thicker spacers, like the 18mm I’m using for the Apex wheels, aren’t as noticeable. But 5-8mm spacers caused a vibration at highway speeds. I’ve managed to minimize it by keeping the contact area clean but have never been able to complete eliminate it and have just sort of “lived” with it, for what it’s worth. Since the Apex wheels are only installed for track events, the slight vibration at speed doesn’t bother me.

Running a squared rear wheels up front does not require spacers for me and that’s the normal “street” setup now.

I had the same experience after installing RB. Tested with 5mm and 12.5mm spacer.

[pokeybritches]

Based on your previous post, it sounds like the spacers are 12mm. Did you install extended length bolts too?

Have you considered a stud conversion? I only have spacers in the rear of one of my M's but no vibration. I haven't tried spacers in the front yet.

[Westersund]

Have you replaced your FCAB? They might be the culprit, spacers will enhance the problem.

[RobMCoupe]

Originally Posted by pokeybritches

Based on your previous post, it sounds like the spacers are 12mm. Did you install extended length bolts too?

Have you considered a stud conversion? I only have spacers in the rear of one of my M's but no vibration. I haven't tried spacers in the front yet.

I installed Apex extended studs. Same problem. I have to buy new set of wheels to eliminate need for spacer.

[dc_wright]

Originally Posted by deemo319

I have had a shimmy in the 80-90 mph range on the highway.

Running 20mm on all four corners (non-m) but I don't recall if I have driven at those speeds since we installed them.

My vibration is on the passenger side rear. This thread actually reminded me to revisit this issue. I hope you figure it out soon.

When you've got a chance to stop by we can pop that right rear off and check the hub to make certain it's fully flush.

[3002 tii]

Originally Posted by Westersund

Have you replaced your FCAB? They might be the culprit, spacers will enhance the problem.

yes sir, new FCABs were installed along with the coilovers and camber plates.

Originally Posted by pokeybritches

Based on your previous post, it sounds like the spacers are 12mm. Did you install extended length bolts too?

Have you considered a stud conversion? I only have spacers in the rear of one of my M's but no vibration. I haven't tried spacers in the front yet.

So the new "premium" brand spacers I have are Apex 15mm (latest design). And I am running GLS TopStud 82mm extended studs.

[Daemonblitz]

Can confirm, always had vibration when running spacers on the front end, ran them when I had the M225 wheels on for street.

[gnx]

Originally Posted by mmm-five

I've got 10mm H&R hubcentric ones on the front of mine (to clear Porsche Brembos), and I've not noticed anything at 140mph+.

But that could just be my fat fingers/ass absorbing everything

Are u running stock rims and tires?

[rueyme]

You need hubcentric spacers with the lip extended to the wheel center bore. At that point the feel is the same as the wheel itself because it is machined to the same hub diameter that transfers to the wheel hub itself unless the wheel is not perfectly centered in the hub it should be no different with or without the spacer.

[Willy Sea]

Originally Posted by rueyme

You need hubcentric spacers with the lip extended to the wheel center bore. At that point the feel is the same as the wheel itself because it is machined to the same hub diameter that transfers to the wheel hub itself unless the wheel is not perfectly centered in the hub it should be no different with or without the spacer.

Absolutely agree. Have used hubcentric 10mm upwards on all our M cars, and no unusual vibrations whatsoever.
However as we can only drive one car at a time, and it can be some weeks between drives if the car is garaged with warm tyres, a flat spot becomes evident on the cars next outing. A quick high speed gallop soon rids the car of those

[Vanne]

I would assume that someone with the skills of Ti, would know about the hubcentric spacers. I wouldent use anything without. Currently ran 12mm hubcentrics at the front, zero shimmy. No issues. Going to be running quite a bit larger spacer on the front when my car is back on track. Ill be getting mine custom made, and off coarse.. hubcentric.. I did have a massive shimmy a year or so ago, that i finally traced down to one of the front tires having a delemination. (astetically the tire looked fine)