I've not been very concerned about strut-tower mushrooming, as my `05 S runs on very lightweight 15" and 16" wheels, and I've got Koni FSD, all of which reduces the strain on the attachment at the tower.

However, yesterday, I compared another car with mine, and concluded that there was indeed mushrooming happening after 45K miles - only 2-3mm of visible bulging, but enough to motivate me to keep it from getting worse.

So off to Mini-Madness for a set of their new reinforcement plates, which fit between the strut-top and the frame.

Some observations about this piece, which is obviously a more effective design than the decorative aluminum tower-topper plates that others offer:

- The installation is a breeze - a half-hour job. Wheels off, disconnect the sway bar ends, remove the three nuts to drop the wheels/shocks, then slide the plates into place and re-attach everything.

- Interestingly, when the plates are tightened in place, they will visibly flatten the mushrooming as you tighten the bolts. This is much less potentially metal-fatiguing vs. whacking it with a hammer, while pulling both the strut-top plate and the tower back to really flat, not just lumpy-but-a-little-bit-flatter, as a hammer will do. The decorative top-plates cannot do this.

- The plate is not going to ever bulge or distort - it's 1/8" steel. The reinforcement more than doubles the contact area with the tower sheet metal vs. the strut itself, and it is not going to bulge up - not ever - the whole tower-top would have to rip out of the car.

- The surprise was that, along with my OMP strut-top brace (useless, except to damp noise and vibration in the body), it "quiets" the car, in the engineering sense, even more than the OMP brace alone.
This seems reasonable, as making that mounting hard-point more rigid will transmit vibration to more of the cars' mass more effectively, and thus damp vibration better. My car now has less cheap-plastic noises over bumps - a nice unexpected benefit for this well-designed piece.

- Oh yeah, and the included tower hole plugs look nice...

 

I assume the plates raise the front of the car 1/8 inch and you need to check the fromt end alignment?

 

I'm guessing the suspension geometry won't be changed, with the possible exception of camber: by shoving the wheels down relative to the frame and control arm attachment points, it seems to me that it would it would reduce negative camber by some small amount. Perhaps .1 degree or less, at a wild guess?

I'm not certain if this is correct, and not clear on whether this is in the better-handling direction or not.

Can anyone enlighten me on this?

 

Negative camber is what you want for better handling.

 

Yes raising it will add Positive Camber. We DON'T want that, we NEED negative camber.

 

Out of curiosity, how much positive camber would be added by raising 1/8"?

 

That's the question of the day

 

Go get her aligned, compare the average of your last alignments and tell us the difference OldRick! It's probably not a whole lot though!

Jeremy

 

I spent $100 on a not-really-needed alignment a month ago. I'm not going to invest in another one. Hoping someone else does exactly what you suggest - perhaps M-M will measure or do the calculation for us?

 

Just a follow-on thought on the magnitude of the camber change issue.

Looking at a set of H-Sport adjustable camber plates:


It is apparent that to get the 3.8-degree of camber change that they can provide, the strut-top bearing has to move what looks like about 1.5" laterally. So each .1" of side-to-side movement gives roughly .2-degree camber change.

The reinforcement plates add 1/8" of HEIGHT to the frame. The wheel assembly pivots relative to a fixed point about a foot away from it, more or less, so adding 1/8" vertically moves the pivot point laterally maybe 5% of that 1/8". Technically, relative to wheel camber, that's known as "not much".

(Yeah, I know it's a multi-element suspension. That just reduces any potential camber change caused by loading - that's the point of Macpherson strut designs.)

It would be easy to measure how much camber change is caused by the 1/8" change in ride-height - just put enough weight on the car to lower it 1/8", then measure the change in wheel angle. I'd be out there measuring this, but I only have a .5-degree bubble protractor, and it's got to be a lot less camber change than I could measure with it.

I'd GUESS that the weight of a passenger might drop the car 1/8", so the magnitude of the reinforcement plate camber change is probably about what you get by bringing your sweetie along for a ride...

 

i doubt it would change camber much at all, and if you are that worried about camber, why not just get camber plates?

 

Because they cost a lot more money?

 

for only $80 more you can get ie fixed plates and have the benefit on more negative camber.

 

IIRC, the Ireland plates have been noted by others as being prone to bearing noise, and the installation cost would also increase another $50 at a guess, due to compressing the springs. So make that $130 more.

 

With 10,000 miles on my IE plates all is blissfully quiet. No bearing noise for me. Could it be that my decorator strut plates are concealing the noise? Another hidden benefit of the decorator plates.

 

no noise on mine either, and installation is free if you do it yourself

 

true for the adjustable camber plates. Not true for the fixed. The fixed ones utilize a beefier strut bushing (oem) from a heavier car (3 series). see my gallery for pix's of the fixed camber plates.

Running at about -1.8 camber each side with factory springs. after a rotation 5k later, no discernible inner wear on front tires, though I do not do a lot of highway at this time. nor is there noticeable bearing noise.

 

I read somewhere that the IE plates retain stock height but the mount in your gallery is taller without question.

 

heyduard - Did the IE fixed plates raise the car? If so, how much?

 

I got the IE plates recently and if it did raise the front I don't see it and I'm really picky about ride height.

Longboard

 

I didn't see any difference in ride height when I installed the IE fixed plates. If it did raise it an 1/8 of an inch I sure didn't notice it. I'm also running stock springs & in 11,000 miles my tire have worn perfectly even.

 

Visually, I, like the others, cannot tell if there was a change in height. In any case, the bushing will be compressed over time, so any height change is a wash. I can see a change in camber. Toe will need to be corrected after installation.

With the windows down, there is some noise from the suspension during a transition over an uneven surface, not unlike the suspension sounds from a WRC car, which is okay in my book. the plates and FSDs went in at the same time, so I am uncertain to what I can attribute the "sporty" suspension sound to.

 

I dont doubt what you say,but that pic in your gallery of the plates makes the IE plate look 25% taller than the OEM plate at a guess,thats alot to ask the bushing to compress.I have fsd and IE adj plates on the way but dont want to raise my car.

 

They are a bit taller, but they also have a bigger bushing. It will compress more than the stock bushing, but I don't see any way for it to not raise the hight. It is considerably bigger. That said, I can't see any difference in ride height after my install, although I did not measure it. It is probably 1/4" at most. That is not going to be visually noticeable. You also would not have the positive camber that comes with the raising of height because the mount adds neg camber.

There is no noise with the fixed camber plate bearings. They are very easy to install and if you use a free spring compressor from autozone, then it is free installation. The most noticeable change that I got was more even tire wear. I always had the outside wear out before anything else. My alignment was pretty normal, but I guess with my driving style, the stock camber wore out the outer part of the tire.

 

+1. at stock camber, the cornering force is concentrated on the outer third of the tire wearing away the outside shoulder (thanks GRM). additional static negative camber will negate that. After 3 months of throwing the Mini into curves and sweepers, I find the fixed plates work very well for the street. As always, YMMV.

I better take a picture of my Mini next to a stock one to see if there is a visible height change.