You are correct in the bolts do not do alot of work if you are adding bottom mount plates like the fixed camber plates, but if you add the M7 or Craven top mount plates the bolts are doing alot of work that as you pointed out they were not designed to do. The bolts are just there to center/locate but using a top mount plate causes them to have to hold a clamp load. Not sure if they are sized for that since I'm not a Mini Engineer. I also found a post were someone pulled the studs out of strut mount while trying to using the stock bolts to straighten a shroom, that would tell me that they are not sized for it.

Agree that the stress if less away from the force but if the force is in the center of the tower and the distance from center to edge is large then less force gets transmitted to the vertical parts of the tower and more stays in the flat part causing a shroom. You want greater area for distribution of force.

The EI plates do have more area since the center hole is smaller then stock but I'd like to have them and a large plate to reinforce the tower. Not sure if EI take up the greatest on the outside dimensions. The offset scares me since its at the weakest part of the tower. Especially if I were racing or have roads like I do in Michigan.

I plan on actually welding the plate or bolting it down in the area marked in red. It is not possible to bolt thru with the EI plates since the mount is behind there but you could drill out the downward facing stud and bolt all the way thru (tower, plate and mount). This may be overkill and I'm not sure what is help just a suggestion.

 

Yeah, I did that and M7 on top and I really like what it did for the handling of the car, plus that old (hopefully real) piece of mind

 

Ok gonna stir the pot. I've been working on MINI's since before they were avail to the public and I've seen so many mushroomed strut towers I can't count them. It doesn't seem to matter where you live or what tires you have. More so on how many holes you hit in the road. Also I have noticed early cars and later 05-06 cars being more prone to it. There seems to be a middle gap of late 03/early04 cars that do seem less prone to it, don't know why just an observation from checking production dates on cars.

As for prevention use either the M7 strut plates or the Craven STD's. These are the cheapest and easiest to install. If you want to go further on prevention go with camber plates. They are usally made of thicker stronger steel than the stock mount and won't mushroom. But they cost more and so does installation. As for the MM and Craven Under tower plates. These plates where just made for marketing. Yes they will work, but the only reason they were made is cause MM didn't have a product to compete with Craven or M7. Then Craven didn't want to be out done so they cut some out too. But in reality this is not an ideal fix. Why you ask? 1st off the Under tower plates are going to add positive camber to the car, Come on guys read around you know we need all the neg. camber we can get, BAD IDEA. 2nd of all install on these is alot more involved costing you more, and they aren't going to work any better than the bolt on plates. You can sit here and debate bolt length and strength all day long. But I've installed a couple hundred sets of strut plates and NEVER had a problem with the bolts. Because I properly beat down the towers correctly and replace upper strut mounts that are too far damaged to repair. Most bolt failures are caused by someone trying to install plates but having too severe mushrooming to be able to get the bolt straight.
The proper repair for all mushrooming should be replace the stock upper strut mounts with whatever stock or camber plates and then hammer the sheet metal back down while the strut is out of the car. Then reinstall the strut and use a top mounted strut reinforcement plated to pull the rest of the sheet metal into place.

 

Thank you Way. You have explained things here in a way even non-tech minded people can understand. I agree with you completely.

Only problem I have with this why didn't you post this a whole lot earlier?

Now let the debate continue....

 

Thank you for the non-tech response but there are several flaws in your agrument.

1) M7 or Craven STD are not cheaper, unless you are assuming paying someone to install them. If you do have a shroom then the cost to install either lower or upper plates should be close because you will need to raise the car and remove the strut (or at least lossen the strut and to remove the weight on it) to straighten the strut tower.
Also if I plan on making my own plates which if I estimate right will just cost me time, and a 1/8 thick by 8 1/4 x 13 inch piece of steel.
2) Camber; by putting an under plates you raise the car 1/8 inch so you move the lower control arm inner point up by 1/8 inch. In terms of ride height and camber that's almost nothing. So I have to agree you will get some + camber but my bet is that the machine will barely be able to read it and my alignment will still be in spec (i'll tell you after I get the plates on and go back to the alignment shop). Also for most street drivers adding camber means greater tire wear. My mini is now a daily driver so I want tire life. If I wanted better handling I'd put adjustable camber plates.
3) Lastly, you proved my point on the bolt strength. The bolt/nut is not designed to counter a shroom, otherwise you could use the bolt/nut to straigten it (I know that steel takes a set but if the bolt/nut had enough of a safety factor to they should be able to straigten a shroom).

Therefore, my first assumption that the top plates stress the bolt/nut is confirmed.

Not saying that top plates won't work or are bad just saying that long term (100,000+ Miles) bet most people will see broken bolts esp if they have the M7 which use the stock bolts/nuts.

 

My M7 top plates were installed at 2,000 miles & used by them selves until 32,000 miles. Then I installed IE fixed camber plates in addition to the M7 plates. Now at a few miles shy of 60,000 all is well. My studs are still studly & no shrooms to be seen.

 

My 11/06 build S came with POSITIVE camber stock, just a tad but seriously... so at least now it's reasonable. And I did notice the improved handling and at (only) 24k miles, tire wear is not unreasonable or noticeably unequal, with your setup but done when the car was brand spanking new (<1k miles)

 

I didn't have any wear issues with tires on the street. At the track that was entirely different, needs the negative camber there bad. The IE fixed plates were installed to give me some negative camber, -1.8 -1.9. I'm more than happy with the improvement. The anti shroom properties of those plates was a bonus. Win-win.....

 

As we were the first to address this issue several years ago and have not heard of any of the bolt " issues " you refer to I think you are off the mark here . Time will tell and so far all it has been saying is that the M7 plates do the job they were intended to .

Randy
M7 Tuning

 

They have worked well for me. Thanks Randy!

 

ok humor me please. i'm looking through the forum reading about mushrooming. was this corrected in the r56? seems like all of the postings are about the previous gen. and if it isn't fixed. is it something that i should fix on a daily driver 08 mcs?

 

i had the same question.

 

Crashton: This is why I don't post tech info. Even though everything I wrote is true someone wants to tell me I'm wrong?????
I've installed a couple hundred sets of strut reinforcement plates. NOT A SINGLE ONE IN 5YRS has came back with a broken bolt.
So I'm not worried about the bolt strenght with the stock bolts. And I'd say 90% of them I installed without removing the upper strut mount from the car, so that makes them cheaper to install. But who says I'm a MINI Specialist.

As for R56 mushrooming, I have seen 1 car with a mushroomed tower, only one but it may have just been the first. Only time will tell. I'm going to keep selling and installing the M7 or Craven Strut plates and they won't hurt a thing.

 

What about the GT Spec. will this guard against mushrooming or are those better? i only ask because i'm planning on the K&N CAI and the GT Spec is supposedly the only brace that will fit. and i'm not totally sure i'm gonna do a brace at all yet. will it be worth while as a daily driver? aggressively i suppose to an extent but not abusive or "track day"ing the streets :-)

 

Way, there are always going to be so called internet experts that are going to claim an augment or theory is flawed. Don't let them get to you. Your expertise with our cars is above reproach. Plus your posts here & elsewhere are a valuable asset to all MINI owners. Keep up the good work & thanks.

 

There is some great information about mushrooming in this thread. My question to you guys is, I'm about to purchase a 09 clubman s, should I be concerned with this? Or should I just buy it and install it one weekend for ease of mind...I live in Philadelphia, which has nasty potholes.

 

Don't stress about it too much, as in getting them in a hurry to put on before you drive the car. Do it some weekend, like I said on your R56 it's just good insurance so you can do it anytime. I'd bet on you being ok driving it for a while.
PS I do have both the M7 and Craven in stock.

 

^^ Okay thanks. I will contact you when I get my hands on a 09 MCCS.

 

Hi all, hopefully this isnt too much of a stupid question, Im still learning so forgive me. I have noticed mushrooming on the drivers side of my 05 mcs, and am looking into the plates and the strut braces. There was a previous poster who mentioned that the handling of his mini improved greatly by adding the strut brace. Is that also the case with the plates? Is there an advantage of one over the other? Thank you!

 

There are no stupid questions when you are new to the game . A strut tower plate of any type will not help your handling . A proper bar can be of assistance in this area however . We incorporated both aspects in our bar , a solid reinforcement plate and a sturdy cross bar.

Randy
M7 Tuning

 

As far as 2nd generation mushrooming: My first mod on my '05 was M7 strut plates, before any mushrooming could occur. I'm a believer: I had a set of M7 plates purchased and ready to go for our '09 Clubman, again first mod. For the price of the plates, and an easy 10 minute install, it isn't worth waiting and finding out if the second generation cars have a problem. And... I don't worry as much about us accidentally hitting a pot hole with the Clubman. It's cheap insurance IMHO.

 

So what's the best non-OEM replacement strut mount? My shop wants $90 each for the factory parts, but Boge or KYB parts can be had for $30-$40.

 

From my limited knowledge, I believe it would be in your best interest to get a Ireland Engineering Fixed Camber Plate to replace the OEM strut mount. The OEM ones suck and the IE ones give you a better ride and handling (from what I've heard). They run $180 a set.

 

Any cheaper alternatives to the M7 or the Madness strut tower reinforcements?