Some of you asked for it and here it is.

Our own Will has worked diligently to put together an easy
to understand technical analysis of what the patented
M7 Strut Re-Inforcement Plate will do for your MINI.....



Strut tower deformation, also known as mushrooming, is one of those problems that continues to plague MINI owners in all drives of life, from track cars to cruisers. It seems like the sheet metal that serves as the mount for the front strut towers was made far too weak for the strength of the suspension. If the mushrooming is drastic enough, it can affect the behavior of the car. Many MINI owners have had to take a 2x4 and a hammer to their strut towers to bang the metal back into place.

The deformation occurs either over time through continuous small events or sometimes all at once with a large event. Likely events can include bottoming out the suspension due to catching air, running off the road or track, or even hitting a large pothole, among other things. All of these conditions impart a force on the thin metal that holds the strut tower that it was obviously not designed to withstand. Using finite element analysis (FEA) software, we can analyze the effects of large forces on the strut tower.These first two images show the relevant pieces of a simulated strut tower. Some of the model has been suppressed to make it easier to see. This model is not meant to be completely accurate with respect to the Strut tower of the MINI, however the shape and contact points are approximately correct and the properties of the materials are accurate.




From the factory the strut tower provides a flattened surface for the strut to rest against. This is important for maintaining straight alignment and proper suspension geometry. Using this model, we simulated an extreme case of the “car” essentially being dropped, as if it were to have jumped off the ground or fallen off the road. The deformation is readily apparent, but to make it easier to see we have enhanced the deformation to make it easier to see. The following image are the results of that fall. Following to see, will be a colored image. The color shows the amount of displacement from the original position. Blue means little or no displacement, moving towards red which is the maximum measured displacement.


It is apparent that a hard impact to the strut tower from below will deform the metal. This has been seen on many MINI’s in the last few year, and this simulation serves only to validate the effect. While the mushrooming of the strut tower is not something that is guaranteed to happen, given the frequency of the effect it is definitely something to be mindful of
M7 is mindful of strut tower mushrooming, and has developed a solution that will help prevent it from happening. The Strut Re-inforcement Plates bolt to the strut tower using the stock bolts that hold the strut in place, sandwiching the thinner sheet metal between two more rigid pieces of metal. This sandwich serves to distribute the force of an impact over a much larger amount of metal, resisting deformation. The following two images show the same simulated strut tower with the SRP’s installed.


The SRP equipped strut tower was then exposed to the exact same impact force as the preview, non-SRP model. The results make a very strong case for the advantages of having the reinforcement plates installed. not equivalent to the previous colored images. The same green or red color does not equal the same deformation from pre-impact in the two sets of images.


As you can see, mushrooming is almost completely prevented, even in one of the most extreme cases we could simulate. Even with the deformation enhanced, it is difficult to see the mushrooming occurring with the SRPs installed on the strut tower. Even in less extreme instances, it is clear that you can protect the integrity of your strut towers using M7’s Strut Tower Reinforcement Plates. The M7 strut tower bar provides the same protection with the added benefit providing extra structural rigidity to your frame. The only question now is which product is right for you?

peter
Team M7
562-608-8123

 

That write-up is really not convincing at all to me. Where was the force(s) applied and what was used as a restraint(s)? What value was used for the force in each example and what material? He says the values are different for both analyses but no numbers are given to explain what the colors are. Is the stress in the first one higher than yield stress so deformation actually does occur? What about the second one with the SRP? What about the strength of the weld with the SRP installed? There is a tremendous amount of information that has been left out of this tech paper and it does not convince me that the SRP will do what you say it will. I understand the philosophy of the SRP, but I am not convinced of the functionality from this paper. Also, was this done in Solidworks with CosmosExpress? It sure looks like it.

 

Why would we do a technical FEA analysis in Solidworks or Cosmos E.
It's all done in a very complex and technical FEA software.
As for the the numbers you don't believe in Will is more than happy
to answer those questions by tomorrow....

peter
Team M7

 

The full Cosmos? You can do FEA with CosmosExpress inside Solidworks...it just isn't the most accurate. I'll be waiting for those numbers tomorrow.

Is there also a way to get a picture with the SRP hidden so the strut tower deflection can be seen in the SRP installed analysis?

 

Just so Weezer isn't hanging out there by himself. You guys seem to have a lot of satisfied customers with your products and I am anxiously awaiting your black strut tower brace with SRP plates.

But... the writeup as presented is really not convincing as it is. I had the same feelings as Weezer, but also please show the comparisons plotted on the same deformation scale and better yet, a von-mises stress plot (on the same scales for both pictures) would really be most appropriate.

From an intuitive engineering standpoint, your products would seem to make a better strut tower structure... but your "proof" as posted is really just a series of colorful pictures. FEA software routinely scales deformations so that the displacement is scaled from zero to max across the full-color range. So you can have something that has less overall displacement, show more red (and a more exagerated picture) than something that has tons of displacment but far more localized.

Thanks for the willingness to put your results up here, I'm sure it will look better when the numbers are there to back up your claims.

 

I completely agree with you. That write-up as it is above is just a bunch of pictures. It isn't conclusive whether they work or not from it. In theory the SRP should provide some benefit, but without the proper support (actual pictures with scale and stress/deflection values) then I don't see how the conclusion can be made that they completely eliminate mushrooming. Boy, I've been thinking too much tonight.

 

I really hope Will wrote that and drew up the pictures on his home computer, and that my tax dollars and the Navy didn't pay for that.

 

Musrooming is a bad reality. Even with my JCW SB, i had slight deformation of the driver strut. This alone was reason enough to throw the m7 SB on there.

 

Oh my....

peter

 

another episode of M7 wars heat is on

 

can you use the existing tower bolts?

what would M7 consider to be the next weakest part of the strut tower
after the plate install? (if the tower doesn't deform, where would the
stress go to next?)

 

Ya man...what was the specific gravy at the crib where this was stimulated and did you account for the cumpooter's wate and colloring? Did ya, did ya??? Huh??? Where's the reel numbers dOOde :impatient :impatient :impatient Come on...what are you trying to HIDE here Peter?:impatient :impatient :impatient I mean...ya can't fool no colege edumacated poison like me ya know...Looks like this was drawn up with sketchomatic lol:

 

Funny, sometimes make me think........

 

The weld's gonna bust... It'll pop open like a tin can. I've seen it on two cars with bad offs at the track. Not only did the top of the tower deform, but the massive force popped the seam weld. IMHO, reinforcing the tops of the towers isn't a bad idea - but a big enough shock will most DEFINITELY pop that seam weld with the reinforcement.

 

Well, for me the next weakest point was the stock strut
itself. It bent badly and to the point where I was forced
to replace them with Konis.

 

dang...!

ive hit some real nasty bumps on my ride... no bent rim, no mushrooming.
perhaps my 205/50/16's saving my car.

 

more than likely, i do not have that luxury, have to watch out, I checked mine today, everything seems fine.

 

It looks to me, like the last two diagrams that show the strut support attached, show deformation in the plates them selves. It makes me wonder what the strut tower looks like underneath the strut support.

 

As previous posters have said, you can't read too much into the pictures without knowing the maximum stress or displacement. These FEM programs like to make color plots and show the range divided up into a descrete # of color bands. It's impossible to tell without knowing the scale of the values what the colors mean. One plot could be showing 100,000 psi peak stress while another could be showing 1,000 psi. The same goes for the deformed shape. FEM packages like to show a (grossly) deformed shape that is deformed enough for you to see where the deformation is. Nothing wrong with that, except when you try to compare plots with different displacements. Again, we could be looking at one plot that has a displacement of .1" and another that has a displacement of .01" (a 10 fold reduction in displacement). We wouldn't know that though just by looking at the color bands if there weren't any numbers.

A good practice, as was recommended earlier is to show the plots on the same scale (i.e. force the plot to have color bands that have the same meaning across the two models).

It's also a good practice to limit the use of "red" in stress/deformation plots to areas where there is a real problem (i.e. an area which would show a negative margin).

 

O.K. I guess we will have to see some #'s.

 

Will should be back home later this evening and I'm sure he'll be glad to offer more insight


Mine go on this weekend. Yay!

 

I'm still waiting Peter and Will. Any numbers or answers to any of my questions? I feel they are very valid questions to ask when the claim is made that this product "= no mushrooms."

 

they are studying right now

 

I can't speak for Peter, but Will has been out of town all weekend and had a very long drive today.

Chill y'all. Seriously.


Every once in a while, people walk away from their computers