While it's worth noting that many airframe parts are replaceable and bolted or riveted in place, it's mostly the "skin" between the frame pieces that provides the stiffness which triangulation of the joints would otherwise provide. The USS has no such triangulation pieces.

An open rectangle does not resist diagonal stresses very well, while triangulated frames cannot be deformed without destroying them. Purely for mechanical engineering, I'd pick the TSW piece.

Oh yeah, my "diagonal braces" are on order. Hard to beat $53.32 delivered from http://www.customminishop.com/.

 

Fooled again I see...........these braces really don't do anything. What kinds of forces are causing the front of the car to want to go up ahead of the strut towers? None that I can think of.......

 

Don't ask me, this is just another lousy vendor trying to force their useless-junk parts down my throat, by making their useless junk a standard-equipment part on the Cabrio. The dirty dogs. Or maybe they just love bolting on extra parts for the fun of it.

Those marketing guys at BMW and MINI sure are subtle in the ways they market their useless junk, and their engineers don't know nuthin...

Either try it yourself or give it a rest, Scott. You are making noise with no experience, and several respected people who have tried these say they work. You apparently haven't tried these braces, and you clearly aren't an automotive structural engineer, so try to keep a stiff upper (and lower) lip...

 

LOL

I'll ask for your degree next time we meet..............

And of course I believe everything I read on the internet.

 

And I'll invite you to swap my diagonal braces into your car and report on your thoughts.

 

What forces are these braces suppose to react to?

 

Nice pics agranger.

 

Quote:

Originally Posted by OldRick

Don't ask me, this is just another lousy vendor trying to force their useless-junk parts down my throat, by making their useless junk a standard-equipment part on the Cabrio. The dirty dogs. Or maybe they just love bolting on extra parts for the fun of it.

Those crazy folks at BMW sticking it to those Cabrio guys . Oh wait there was no extra charge They must have decided they were making too much of a profit and wanted to give something back to the people. On a more serious note and the underlying reason I thought they were a good idea stemmed from a conversation I had out at Willow Springs with the engineer who designed BMP's strut tower brace way back in the infancy of our cars. He always wanted to have a piece extend from each end of their bar to the frame much in the same fashion as the Cabrio braces. He said that one side , the passenger would have been no problem but the drivers side was going to be an issue. He never got the go ahead from the Mfg ( BMP ) to proceed with the project due to cost restraints. Mind you that is all this guy does for a living , design race car chassis and related components . For the minor charge and hour or so to install them it was well worth the " investment " in my opinion.

Randy
M7 Tuning

 

Again............what exactly were these suppose to do?

 

They're obviously resisting some forces that causes flex. Not many people will know the magnitude and cause of these forces, and to be honest, they must be significant on a cabriolet. Maybe the roof on the coupe lowers the magnitude of the flex, but i doubt if it completely removes it.

 

OldRick
Please post your feelings on these braces when you have them installed.
Thanks, Steve

 

If you look at where they are installed, they extend out in front of the strut towers. All of the loads are at the tower, there is nothing attached at these points except for the bumper and engine. I don't see any way for any loads on a hardtop to be present this far out in front of the towers.

This link shows the location of those braces. IMO they are there to stop vibrations from the front of the car.

 

Sure will.

 

I was just reflecting on the long-held myth that the MINI is so well-designed and built that "it doesn't need" any of the usual braces and props to make it more rigid for better handling.

Randy Webb, for example, was widely quoted on NAM as having measured negligible motion between the strut-tops of a MINI on a race track.

Yet, here we are, debating the merits of different designs, while almost anyone who has tried using strut-top and lower frame braces will testify that they provide a large improvement in handling precision in any conditions where the suspension is stressed.

I can personally testify that the differences from adding bracing are both unmistakable and obvious, at least here on my local twisties. I'd bet money that I could reliably tell whether either of the braces currently on my car were removed.

So what I was wondering is: who are these self-appointed gurus who don't bother to experiment with a product, but simply prognosticate that "it won't work" without any personal experience?

The other part of this, philosophically speaking, is that it seems that when some people buy a part, it instantly becomes the only part that could possibly do the job, and all other products from other vendors are dubbed as junk. These are the folks who will comment from complete ignorance as if they were authorities, and never even wonder if there might be something better than the piece they bought. Perhaps it would somehow diminish their self-esteem if someone else had something better?

But back to the thought: I have no idea whether these braces translate to faster times on a track, and we'll never know, because they are illegal in all but unlimited autocross, and any other timed auto-sport has so many other variables that the effects of chassis bracing would be nearly impossible to measure. To make it worse, serious racers who do use these things and find them useful probably aren't going to pass their secrets to their competitors...

They are certainly mostly useless for handling if you live in flatland like Miami, although they can improve launch control.

So, in parting this thread, I ask the question, "Who are these gurus, and how do they come up with clearly false statements like "the MINI is so stiff that it doesn't need bracing?"

 

Exactly....
I'm sure the Mini engineers didn't come up with this random part using the SWAG method. More than likely Computer Aided Modeling proved that reinforcement in this particular area would improve things in the more flexible cabrio..

Sounds good to me. I ordered a set from Brad this morning...Impressions later..

 

First of all, the Mini is a unibody and therefore, any twisting and flexing forces will radiate throughout the vehicles body/frame. It will be harder to twist the vehicle diagonally if ANY PART of the frame becomes more difficult to twist, including the front or back.

However, I believe those braces are intended to quell cowl shake. I could be wrong, I have no idea to be honest.

 

Ah yes the eminent sage doth speaketh.......

Now lets talk about the way humans self-enforce the buying decisions they make.....

 

You've already been demonstrating exactly that through this entire thread. How's your OMP brace, Scott? Do you like it? Is it a better buy than anything else on the market?

Please. let us know again...

 

Huh?

What does that mean. I don't have the OMP lower brace.

 

Then why on earth do you presume to give advice about it and other products when you have no personal experience with any of them?

 

Gee.......I thought that's what you were doing.

You are the one that has to try and justify to yourself the purchase of a product that has little if any proof that it actually works. I love the irony of your sig........

Why don't you read post 50 again. I think you missed something..................

 

I suppose since nobody has actually subjectively taken g readings before or after an install and posted them here, there is little or any proof here.

My car has a gps based vehicle dynamics feature that accurately measures linear and lateral g forces. I should take video of the readout as I drive before/after an install and post it.

Now I am curious. Is the chassis stiffening (and its effect on handling) provided by a STB and then also by a USS not real? Is it not significant enough to be measured? IS the sensation of improved handling felt by several in this thread only psychological? Some sort of mass hysteria? Or will the installation of one or more devices to "tie together" "weak points" in a design that is not intended for maximum handling actually help?

If it is mass hysteria or snake oil and there is no proof to be found I suppose a lot of people who are autocrossing their cars (be they minis or not) who have dumped hundreds if not thousands into suspension tweaks will be lining up to get their money back.

I mean if chassis stiffening hasn't been proven to help then we all should (with proper training) be able to pass Porsche 911s on a twisty track with stock Minis.

Succubus hit the nail on the unibody head by the way. Ever try to twist a pop can? twists where there is the least reinforcement first right? even if you only put the load on the ends.

 

I have no idea whether or not these products actually contribute to a better handling car because I have never seen any kind of test to prove otherwise. The only data we ever see is from folks who have installed them and then posted how much better the car "felt". My problem with this is that there were a couple of studies done recently by 2 different univ. that concluded that people who by a product/service with little or no way to validate the effectiveness have a very strong bias to affirm the benefits to themselves and others. Similiar to the placebo effect of drug tests. For example, if someone buys a product and they have no real way to effectively test it's benefits that person will want to believe that the product performs as advertised. I am not saying that any of the products discussed here are bogus, but I would like to have more than a post about how the butt dynio says it works. I myself have bought many products that really didn't perform as advertised, so I have a stronger desire to make sure I get what I paid for.

I am all for chassis stiffening.....absolutely nothing wrong with that. Just look at how a roll cage will benefit the cars handling. But there are several products that do absolutely nothing, or very little, for the cars handling. Such as the rear strut brace that doesn't even attach at the towers, some of these are of very questionable benefit.

 

OK, I've said this before, but here's my beef with the M7 strut tower brace: It is too narrow and long to do much for twisting forces, so the only real potential it offers is to keep the tops of the towers at a constant distance apart. That is, it must work in compression (or its negative). But look at how the bar is attached to the plates: it uses large (10mm cap screws) in longitudinal slots. These slots are in the axis of compression, allowing movement in that axis. What's stopping movement? The torque on those 4 big cap screws, but they are threaded into aluminum--you're not getting much strength from them, so they are not offering much resistance to the plates moving in and out against the bar.

If you look at other strut bars, they are usually attached to the plates with bolts that are orthogonal to the axis of compression--and they work.

So, my conclusion, in the tradition of Dr Obnxs: The M7 strut tower brace is most likely not doing much, as is the M7 USS due to the rhombus design and the twisting forces involved.
However, I do believe there are STBs that work, and under braces that work.

And as you all should know, I have personal experience with most of these products. Not that my popodyno is calibrated any better than other's.

 

And anyone who wants to read more on any of these topics (including some very heated debates) need only do a search for M7 uss on this supension forum.

I for one cannot quantify the improvement which I have indeed felt in the cabrio's handling from the USS -- although I'll be first to admit (as I have often done) that I get nothing out of the STB except for the anti-mushrooming plates. I will say, however, that for months I've driven over the very same speed bumps in our parking garage (and at the same speeds), and there is NO question that the car feels a lot more solid (it no longer rattles and creeks like it's being shaken apart). I can't diagram the forces at play nor quantify how this translates to driving the twisties, but as I've suggested in another thread, maybe I'll do a hemorrhoid test -- go over the bumps with and without the USS and see at which speed the 'rhoids flare up.