JMHO, but even if they don't affect lap times, they'll undoubtedly provide a longer life for the unibody...

 

............or shorten it because of the additional loads imposed that weren't engineered for.

Great discussion all the way around. Just the kind of thing that makes this site one of the best.

Only a long term test will determine the pro's or con's of either system. But as with all mods, you takes your chances

 

Roll cage...nuf said

 

agreed

 

Just for a somewhat related data point, early spring a built by bones rollbar was installed in my car (onasled's old bar). My Cooper has 95,000 miles on it now, so it has seen some use. While I did notice a difference in handling after the roll bar was bolted in, it wasn't a huge difference. I think most of the difference was actually mental / placebo. There was a difference in sound, and my brain wanted to believe the car was going to be "stiffer". So, the sound must be due to increased stiffness. And the increased stiffness must be a good thing, and must make my car handle better - so I think I'll drive it faster / harder.

Of course, my rollbar is only connected to the back half of the car, and this thread is about the front half mainly...

I'm not sure exactly where I stand on the whole mental / placebo side of tuning... Is a part that doesnt really do anything, but you believe it does so you drive faster / better a good buy? I'm not saying that any of these braces are parts like that.

 

Wife and kids in car....'nuff said

 

That's the part that causes accidents or gets your a$$ kicked in a race you don't belong in.

 

My 2006 MCC had an OMP frame brace for 6 months, and was updated to an M7 USS a few weeks ago. The OMP cannot be installed with the M7 at the same time.

At the time of my OMP installation, three suspension mods all went in at the same time: OMP brace, Koni FSD shocks, and a rear sway bar. The handling was transformed and the car felt great. However it is really impossible for me to say which effects came from the OMP vs. the other suspension mods because everything was installed at the same time.

I can, however, comment on the transition from OMP to M7 USS. The M7 took the handling to another level. Keep in mind that I have a convertible, where the effects may be more pronounced than in a hardtop. The car now responds much more quickly and accurately. I can apply a quick twitch to the steering wheel to go around a pothole, and the car responds immediately out and back. Previously, it felt more like I was having to control the car and actively steer around the pothole. Looking back at it before the M7 USS, my impression now is that it was as though the wheels were in constantly changing state of slight misalignment, wanting to go in different directions rather than working together. I think this was an effect from the convertible's body flex. I cannot comment for the hardtop but I highly recommend the M7 USS for the convertible.

 

ouch!

 

That's the part that causes accidents or gets your a$$ kicked in a race you don't belong in.


snid is not that kind of person, by the way...

 

rkw,

Thanks for the thoughtful input. Helped me understand the relative value of both brace items. Your post gets to the heart of the question that started this thread. Hope others are comfortable enough to post their experiences as well.

Happy motoring,
John Petrich in Seattle

 

rkw
As above thanks for the info about the pieces not working together. I hope that helps everyone who may have had thoughts about buying both at the same time. It may also help people on a budget as to which product fits the budget. Both work. I guess it's just how far you want to go.
Thanks for the input.

 

I know that.
The reference wasn't towards him at all.

There are, unfortunately, many that are like that. Always have been always will.

It was a joke,, that's why I did the winky emoticon thing.

 

I agree. Both the OMP and M7 serve to stiffen the frame. The M7 does it to a much greater degree but also at a much higher cost.

Adding to my comments above, my intuitive feeling is that frame flex has the effect of causing a lag in responsiveness of several components including the steering, springs, and struts. The frame flex participates like an active component during steering, body roll, hitting bumps, etc. but does so in unintended and unexpected ways.

 

I got a great deal on the OMP lower strut bar about 5-6 months ago when scobib's hook-up was moving and wanted to clear out some stock.

My first, overwhelming impression was a noticeable 'reduction of drama' in turns, especially tight turns where there are surface imperfections (bumpy), sand or gravel. In those loose situations, I can't say that the car oversteered, but it didn't understeer as much as it did before. The front end just didn't skitter (lots of tiny bounces) as before... it seemed to track better and keep the tires in contact with the pavement in a more predictable fashion.

This is one of my favorite, under-rated mods.

 

But I gotta say, the whole discussion was very civilized. seems there are two products that work to differing degrees at different price points! Sounds good to me!

Matt

 

It appears that those who purchased the OMP bar either got a deal from a buddy or had a bad experience with overcharging vendors. Can anyone point to a reasonably priced/honest source to purchase this product?

 

I'm also interested in a reasonably priced OMP bar.

 

agranger,

Thanks for your update on your experiences and reviving this thread. We need this type of feedback. This entire area of suspension and chassis development is one where I feel that there is a lot more to be learned. However, we are lacking in information until more experiences like yours accummulate. Review my post #99, where I liken this mid-chassis brace discussion to the original discussions of strut braces back in 2003.

I agree with Maximini, in his post early on in this thread, that the MINI chassis tends to "fold" in the center, I say "like a giant hinge". I also believe that there is compliance from the mid-chassis area to the front subframe. These two, the hinge effect and the compliant connection to the front subframe, are a form of compliance that affects the spring, strut, and tire performance and has noticeable effect on weight transfer in cornering and braking. Last winter I started working on a homemade approach to improving mid-chassis rigidity that I am willing to share. Here are two postings from our local BMW Club website that describe some experiments that I have made with homemade mid-chassis brace systems. I hope that they are of interest.
http://www.bmwpugetsound.com/vbb/showthread.php?t=30115
http://www.bmwpugetsound.com/vbb/showthread.php?t=31349

Regards,
John Petrich in Seattle

 

Before I upgraded to an M7 USS , I was using an OMP frame brace from RallyNuts that cost about $75 including shipping from the UK.

 

the stuff looks great. Only one suggestion: If you can put a 90 degree bend on the edge of the plates (3/8ths of an inch or so) the plates will have greatly increased immunity to any flex. Don't know how much this will help as the tunnels is somewhat "boxed" now, but it is a long run of the plates..... to test I guess you could bolt on some "L" stock....

But as usual, your being creative in all the right ways. How do they feel?

Matt

 

John finally shares his obsession! Glad to see it hit the forum here... Curious to know what you'll have strapped-on for Laguna Seca?! Either way, enjoy...

 

I'm almost afraid to ask. What are your hobbies besides cars?

Matt

 

Matt, you know, as I was typing that, I almost changed some words but thought no one would have such a dirty mind to think such things! Boy, was I wrong...

 

I don’t discount the experiences of those with OMP style brace but consider these points; the bolts (2) that fasten those types of braces are small with only 41 ft-lbs of torque applied, not much security, and they do nothing for the control arm bracket. The sub frame is substantial and doesn’t receive the credit it deserves keeping the body hinge in check where it counts the most. The section of body work behind the front seats, forward of the gas tanks at the upper edge has a lot of reinforcement. Combine that with the section above the rear axle carrier and you have very stout resistance to the hinge effect. I agree the floor pan is flimsy and that’s one reason I believe targeting that area won’t yield much extra rigidity, unless the brace goes all the way to the door sill area. The area under the seats is so flexy it makes me think of a Harley I had long ago with a seatpost spring or one of those big rigs with suspended cabs. Anyway, I think those sections of the cabin, not counting the center console channel, are almost independent from the rest of the body. The roof and B-pillars do more for chassis stability than the floor under the front seats. I think the heat shield above the exhaust pipe is misleading, once removed, the bracing forward, above, and aft in the channel become apparent.

The bottom line is, even after the rubber has been removed from the suspension pivot points there is still more flex in the suspension components than the body.