Mr. **** me about weight doesn't want to add anything unless it's worthwhile... So, while I saw and see the potential structural benefit of the OMP, the USS, by incorporating more points, seems to better triangulate the frame, as meb just expressed.

A visual of the two, considering the forces applied, leaves one thinking that the USS might provide additional stiffening benefits. If so, one then would need to decide if those merit the additional cost. Much like I wanted more for an ECU solution, I decided that I was willing to pay more for it...

The basis for reasoning is simply the design, with common sense dictating opinion, which might not be totally accurate, I agree. But when the input or opinion of others, especially a good number of them, it further validates those initial gut beliefs.

I'd like to add that the many who purchased and later publicly praised the USS were not previously loyal M7 fans, some are/were even totally new to the MINI scene. That personally for me has been quite a strong testement to the genuniness of the sentitment.

Until I hear from many more regarding the OMP, the couple favorable reviews expressed thus far, one from a buddy of an OMP dealer, also need to be factored into the equation...

meb, I'm waiting for your input!

 

I picked up an OMP bar around a month ago for $70 from a local guy who can get OMP parts. It installed in around 2 seconds.

Nice improvement. I'm not running a strut tower brace, just this lower brace. Hard to believe the difference ... much less torque steer, feels more planted in hard turns.

Very happy with my purchase.

 

Glad to hear some opinions.
I guess now the question is will they work together????

 

guy who posts on Roadfly installed M7 USS and upper strut bar on his 06 MCS and posted detailed impressions here:

dpcars.net

He is very analytical and I appreciate his comments. He is serious track junkie so I would trust his impressions. Read for yourself.

I installed lower OMP brace and picked up a little understeer from it, so it must have stiffened the car a little.

 

Glad some others noted the bump in understeer.

 

I also noticed this ... but it works well with the rest of my setup:

KW variant 1 coilovers, Ireland Fixed Camber Plates (-2 degrees), 22mm rear sway bar.

The rear sway is set on full soft, but I may go stiffer soon.

 

I think ground clearace over speed bumps will be an issue. At least on my 40 series 16" tires. I already bounce on the floor in that vicinity once and a while. I think the M7 package would not have the clearnce issue and may be more complete. Let us know.
Thanks

 

If there was introduced understeer, I think I would have noticed it - I did not, even on back-to-back runs with and without the bar. I noted more of a planted feel on corner exits when I was rolling back in the throttle. I've been running one for many, many track days and a full autocross season now. If there's any uneven spots in the surface, the car seems hooked up harder over those spots based on my back-to-back bar versus no-bar testing. Turn-in also seems crisper based on my testing.

I'd like to hear from someone that's got a stock suspension setup - mine's far from that. In the case of a stock setup, it might be noticed, but with all the negative camber up front, alignment, H&R/Bilsteins, and H&R rear swaybar, I noticed NO additional understeer during any part of any corner to date... tight, decreasing or increasing radius, transitions, open sweepers, etc. All I noticed is what I mentioned above...

And, FWIW, the "friend" of mine that's an OMP dealer didn't even know they had anything out for the MINI until I asked if he could get the lower bar for me to test... So, there's no sway there. In fact, I was highly skeptical until I did my testing. He only sells locally, too, so I'm not out to make him any money.

I'm running 205/45R16's on the street and haven't bottomed the bar out. Track wheels/tires are 225/50R15's.

 

This would be easy to check. It doesn't set any lower than the center air dam under your car. If that's scuffed up you'll definitely have issues. See the pic in the first post for reference.
You're certainly right about the USS having a lower profile.

 

I understand being wary of testimonials from a few die hard believers in anyone's product ,as I am the same way. However I did a little survey and on this site alone in various forums there are over 18 individuals with good things to say about the USS . Additionally here is a review by Go Motoring which may shed some light on the subject .

http://www.gomotoring.com/reviews_mo...?id=25_0_3_0_M

Now as you all know we have several close family members of the Go Motoring staff tied up in the basement so this review may be tainted as well.
The thought that the USS may be too stiff for the supposedly weak upper structure is quite a departure from the usual claims by the internet " experts " that say the mini is so stiff it doesn't even need a upper front tower strut. Talk about extremes LOL . Somewhere between the "its too stiff" and the " its too weak" is the truth and we feel that is just what we have addressed with the USS. I may have one of the most developed suspensions on this forum and if I could tell the difference with the last addition , the USS , then I know it is doing something good. Not being content with just my own personal evaluation we had Will Turner drive my car at California Speedway and in his words " I would race it as it sits " says it all to me .You can read his evaluation of the car in the April 06 issue. The combo works and it works well. If the OMP bar is all you can afford then that is what you should get . If you can afford to get the best then you should have an idea as to what that is based on the many evaluations given by completely independent owners.

Randy
M7 tuning

 

Hey Randy. Good reply.
I do think the USS is a good product. Darned near picked one up at the Dragon as you may remember. ( Nice to meet you finally BTW )

Both system have shown nothing but favorable reviews. The difference in numbers of reviews is simply a reflection of the amount of exposure.

I am dead serious about doing the comparison like I mentioned in the previous post. An after thought though is I'd gladly pay the expense of the crush inserts. It dawned on me that that would be out of pocket for you guys and eating that cost is unfair.

 

Well, for starters, I can tell you that the MINI isn't as incredibly stiff as everyone makes it out to be. On factory suspension, using tires with factory-spec grip, the chassis is more than stiff enough to give the impression of a very solid platform. However, raise the spring rates, reduce the suspension stroke, and add sticky tires, and numerous creaks and groans will signal a fairly large amount of flex in the unibody and subframes of the car. The MINI may be much more rigid than other vehicles in its class, but like any street car, adding sporting modifications with a focus on fast street and light track use will push the entire structure of the car beyond the specifications engineered into it by its designers.

My concern isn't with whether or not the USS functions as claims. There's no doubt in my mind that the USS introduces a substantial amount of additional rigidity to the front subframe, and therefore to the front suspension pick-up points. This results in suspension geometry that stays closer to static settings under load, which translates to higher cornering limits and a more direct feel through steering wheel and seat-of-pants alike.

However, that front subframe and the suspension pick-up points were designed and run through numerous finite element analysis cycles by factory engineers to flex a precise amount, no more and no less, so that the flex caused by cornering loads is distributed evenly across multiple parts, preventing any one part from taking the brunt of the load and succumbing to fatigue and mechanical failure. The USS adds a very significant level of rigidity... to a single substructure of the car. The cornering loads do not change (in fact, they increase), and have to be dealt with by some part of the car in one way or another. It would seem to me that most of the load would be transferred from the rigid subframe to the unibody, a spot-welded, thin, sheet metal structure, through mounting points that have not been reinforced to cope with the additional load being transferred through them.

With that said, suspension modifications, even springs alone, will introduce the same problem by transferring additional stress at the suspension pick-up points, and increasing the torsional and bending forces placed on the unibody as a whole, but it seems like the strong rigidity added by the USS to one part of the body may eventually contribute to additional fatigue of the unibody if it's not accompanied by a few extra spot-welds (or seam welds) in choice locations, a roll cage, or similar modifications to reinforce the entire structure, not just one part of it.

Again, this is all theory in the case of the MINI. I do have a reputable source that has seen this type of modification cause stress cracks and more on other vehicles, but this remains to be seen on the MINI, since the USS hasn't been around for a long time. The MINI's structure could very well be strong enough to cope with it, but it doesn't hurt to get your car up on a lift and inspect the structure thoroughly for stress cracks every few months!

 

[QUOTE=iDiaz]Well, for starters, I can tell you that the MINI isn't as incredibly stiff as everyone makes it out to be. On factory suspension, using tires with factory-spec grip, the chassis is more than stiff enough to give the impression of a very solid platform. However, raise the spring rates, reduce the suspension stroke, and add sticky tires, and numerous creaks and groans will signal a fairly large amount of flex in the unibody and subframes of the car. The MINI may be much more rigid than other vehicles in its class, but like any street car, adding sporting modifications with a focus on fast street and light track use will push the entire structure of the car beyond the specifications engineered into it by its designers.


Great info where were you when we were getting hammered by the " non believers " duringthe strut tower discussions ?

Now as you say here our buyers are adding " sporting modifications " and are well aware that they are pushing their cars beyond the specifications engineered by the designers. The additional rigidity of the USS is spread throughout the unibody of the car not just a couple of points . I think your theory has a lot more validity with a OMP style single bar if at all. The USS is a THREE unit system covering almost 40 % of the car and does not concentrate on one single area.
As for your concern as for the possibility of causing the car to operate outside the boundaries set forth by the engineers that is what being a enthusiast is all about . getting the most from your car. If we were to believe in your theory the aftermarket business would be rather weak and our cars would be far less exciting and rewarding to drive..For example if you have coil overs on your car think of the poor strut tower tops . They cant handle a soft stock suspension the tops may blow rite off with stiffer coil overs . That supercharger will never last with a 19 % pulley. If you put that lightweight crank pulley on the crank shaft will jump out of the car. Don't even think of changing to a stiffer sway bar , the car will split in the middle. Wider wheels , the axles will snap. Bigger brakes , the control arms will fatigue faster. Bigger throttle body , too much gas and the car will explode. You get the picture

I have the first system ever put on a mini.I have over 55,000 mostly hard miles on the car. Between the track and frequent canyon runs I have given the system as hard of a workout as it may ever have and the car is up on the lift at least bi weekly. We have been monitoring the USS as well as other items test items since day one and will continue to do do. Should there be a problem , and there has not been one so far , we will be the first to talk about it as well as the fix if needed. That is the reality. As for theories they are like opinions and every one is entitled to their own .
For the most part modifying a car will always cause advanced fatigue there is no free lunch. If you want your car to last forever , don't drive it . If you want it to perform you deal with that reality as well.

Randy
M7 tuning

 

Hahah, no doubt.

As far as I can see, the USS concentrates most of its rigidity efforts by triangulating the front subframe. The load from the front subframe is still transferred through its mounting points adjacent to the small, stand-alone middle bar. This bar only serves to reinforce that section of the unibody in a lateral direction, and does absolutely nothing to reinforce the sheetmetal in a longitudinal direction, which is how most of the stress is transferred, especially during braking and cornering. Braking and cornering probably account for most of the stress that is transferred through the subframe mounting points, and the only way to reinforce this would be through longitudinal members to improve bending resistance, which the USS does not utilize on this portion of the unibody.

Of course! But there's a difference between adding a single lateral bar (OMP) to connect the two lower control arm pick-up points, and adding solid aluminum bars connecting the entire subframe together. It's like comparing adding a 15% pulley to adding a 19%+3% system. Sure, they both take the car out of the production specifications, but you can be damned sure that the 19%+3% is going to produce negative side-effects much more quickly and dramatically than the 15%.

If we all had race car budgets, a full roll cage to reinforce the body as a whole, and enough support to replace parts and rebuild engines and transmissions after every canyon run or track day, this would all be well and good. I don't, and many others don't have that sort of budget, either. For that reason, I would suggest that most people run a 15-16% pulley, and give fair warning to those wanting to run a 19%+3% setup. To end the analogy, all I'm offering here is a fair warning to keep an eye open for any stress-related side-effects from the USS, a part that I consider to be more at home on a race car than on someone's daily driver.

Well, you haven't had it on the car for 55,000 miles, but yeah, it's good to know that you guys are keeping an eye on it, and hopefully will notify USS owners if any problems do crop up. Regarding no free lunch, of course. If you want a race car, expect to have to take the whole thing apart once a year and inspect every nut and bolt. If you want a street car, don't expect race car performance, and be wary about parts that offer race car performance for the street. There's no free lunch when it comes to race car technology, where upgrading one component to the upper echelon of performance requires you to balance that modification with other complimentary modifications. In this case, I feel the USS needs a roll cage, but again, that's just my theory. Your mileage may vary.

 

"As far as I can see, the USS concentrates most of its rigidity efforts by triangulating the front subframe. "

No, the USS works as a three piece system . The biggest area of concern was the mini unibody wanting to " fold itself " around the center u shaped tunnel in the floor during lateral movements , not merely stabilizing the front sub frame . One of the biggest results of the USS is actually in reducing the Mini's inherent " wiggle " in the rear of the car when encountering a bump in the middle of a high speed turn for example. As has been reported by many the added performance is felt at both ends of the car .

As for it being a race car only modd can we quote you in the Adds We will use that as a selling point . We feel that the Mini engineers you referred to were able to get the body strong enough to take on our USS. We will keep a eye on it anyway .

Randy
M7 Tuning

 

According to BMW folk, the mini's passenger cell is a monocoque and not a uni-body in the traditional sense. If true, I find vailidity in tethering the sub-frame and this 'monocoque' together...It makes sense to me in any event; strut bars have worked well for me inlieu of a full roll cage. The USS triangulation is a great way to tie things together, in my opinion.

 

How was this determined?

That wiggle is more likely a product of the soft bushings used to mount the rear trailing arm, but it's possible that the USS' added rigidity could reduce the way that wiggle is transmitted through the body, and therefore how it is perceived to the driver. For example, Porsche's new Cayman increased spring rates without any perceptible hit to ride quality, thanks to its stiffer fixed-roof construction:

Hahah sure, if you kick one down. I'd be glad to give you my first-hand impressions. I'm sure the performance improvements are nothing short of astounding, and you know how I like to drive. If anybody can determine the long-term reliability of this modification, it's me. I'm planning on putting a cage in the car within the next year or so anyway.

I'll keep my fingers crossed! Good lookin' out.

 

Monocoque and unibody are one and the same:

http://en.wikipedia.org/wiki/Monocoque

Both describe a design where the body itself is the load-bearing structure, as opposed to body-on-frame (Corvette) or space-frame (most pre-1980's race cars) designs, which use a main skeleton to bear loads, with the body bolted on for looks, aerodynamics, passenger cell, etc. Some automotive enthusiasts tend to view the monocoque as a vehicle where the suspension is bolted directly to the body without the use of a subframe, which doesn't really describe what was done in designing the MINI.

Perhaps. In taking a closer look at the USS, it looks as though it does distribute the load to two additional mounting points, but I'd still keep an eye on it, since those locations were not engineered with that additional load in mind.

 

Hey this was a private discussion bewteen Ivan and I LOL .

Interesting point regarding the monocoque construction. Was there any one specific handeling issue that you feel the USS helped control or eliminate? For me it was the annoying " wiggle " when the chassis was unsettled by a road deflection while in a turn . I do appreciate comments both good and bad from those that have real time experience with the items in question as well as random theories

Randy
m7 Tuning

 

Hm. Read into it a bit further:

By this description, the MINI is still a unibody. Seems like the separation between monocoque and unibody has blurred in recent decades, though.

 

Randy - I lost the replacement nutserts. Your hired help (son?) was kind enough to send two additional nutserts yesterday. So it's still hanging in the garage. I have a lot of annoying wiggles according to my wife...


Monocoque - French for Unibody - yes I know. The discussion was a loose discussion, meaning it was anecdotal to the real topic. But I did write pasenger cell and the BMW folk were particularly particular about stating that the passenger compartment was in of itself the unibody or monocoque.

Where as, and this is my assumption so have fun with it, most traditional unibodys are not so specifically designed around the passenger cell. It's uniqueness can be found by simply looking under the hood. Perhaps they were splitting hairs by trying to split the difference between traditional and non-traditional. I came away from the conversation understanding that a lot of focus was centered on the passnger cell, which in this case is everything aft of the windshield.

I will keep an eye on the two attachment points in the moncoque ...perhap four points in the unibody would have been better??? Randy, any thoughts about this? Ideally and practically?

 

So, how about that OMP bar? :D

 

Still like mine

 

All,

This discussion about underbody frame braces reminds me of the discussions in Y2003 thru Y2004, on NAM, regarding the value of top side strut tower braces. I'll explain myself.

The top side strut tower brace typically consists of a single slender bar that runs from side to side across the engine compartment and connects to the tops of the strut towers. The strut brace hardware typically involves flexible or adjustable connections to the strut towers. They are not triangulated to the strut towers or to the unibody. They can be expected to be rigid only in tension or compression, that is side to side forces. Rotational, or diagonal forces will cause the brace to lozenge and not contribute to strut tower rigidity. The top side strut tower braces fundamentally don't have sufficient rigidity to enhance the inherent rigidity of the unibody in the area of the front strut towers.

This description of the top side strut tower braces exactly describes the under body braces that are discussed in this thread and that are commercially available: slender bars, untriagulated, flexible mountings, ...

What are the conclusions about the top side strut tower braces? Well, there is a wide diversity of opinion. Some people attribute significant handling improvements to their strut tower braces. A large and knowledgeable group of drivers and competitors minimizes their potential benefits and considers them a waste of money. The critics cite lack of measureable benefit on the track times and raises fundamental questions about their rigidity, as I did above.

I think that we can guess that in the final analysis, the conclusions about the usefullness of the under body braces will be similar: a group of true believers, especially the convertable owners, who feel benefit from the braces and a larger group, who feel that these underbody braces fall far short because they are fundamentally not rigid enough to enhance the inherent rigidity of the unibody. The benefits to unibody rigidity may be detectable, but small. Certainly not substantial.

I'd be interested in what others conclude about the braces and my thoughts.

Regards,
John Petrich in Seattle

 

John that was a very well put post and illustrates the wide range of opinions about this subject. On one hand we have an opinion that the USS is too strong for the average car and should be a race application only and combined with a roll cage etc. On the othe side of the coin as you mention there are some that beleive that due to the construction of the parts they will do little if no benefit as they are not strong enough. My feeling is that the truth is somewhere in the middle which is a good thing as far as we are concerned. I have no numbers to prove it either way just a faster, more controllable car.Thanks for the thoughtfull post.

Randy
m7 Tuning