We have finished production on the Rear Dtress bar, and it has come out beautiful.

Take a look at it over a the vendor announcments.

www.northamericanmotoring.com/modules.php?op=modload&name=phpBB_14&file= index&action=viewtopic&topic=20116&for um=35

Thanks
Dan
Pilo Racing

 

Thank you Dan for your post and new product.
How much does it weigh? Including hardware.

 

The whole thing weights under 5 lbs. But you are alse removing about a 1lb and a half or ogigional PArts as well, so you do not gain all that much weight. I don't have a digital scale to give an exact weight though. The bar is made out of Light Weight Tubular Oval Aluminum Bar, and the brackets are made out of a Textured and Powder coeated Steel and are very strong to hold the seat in place as well.

Also incase anyone tried to check out on hte site, there was a shipping charge error that made the shipping come out way to high. Thiis has been corrected.

Thanks
Dan
Pilo Racing

 

Cool ... what does it do? How much deflection have you measured between the rear strut towers with and without the bar?

 

Besides measuring deflection, there is another thing I was thinking about for strut tower braces in the front or rear.
By having the extra strengthening a strut tower brace contributes, a MINI chassis might suffer less metal fatigue over time and maintain it's reasonably good rigidity-maybe less rattles and creaks, maybe better handling even as you put more miles on the suspension/frame.

 

Minihune,

You hit the head right on the nail.

There is little to no deflection on your car now. but after autoX and spritied rriving, This bar will help keep it that way. It provides pressure toward the center of the car keeping every thing nice and tight.

Thanks
Dan
Pilo Racing

 

Can you explain how this bar minimizes deflection? I'm having a hard time understanding by looking at that one picture... Thanks.

 

As a follow-up, how much force is exerted on the bar during autocrossing? Is it in tension or compression?

 

not to be a weenie, but that bar adds absolutely no torsional stiffness without triangulation, either from a diagonal cross member or large, non-pivoting gussets.

 

interesting point, architecturally speaking I would agree, unless the connection points have a spread attachment point ala the BMP front strut brace...no?

 

a la "large, non-pivoting gussets"

 

Couldn't I just use something like this?

 

ok, gloves are off. this thread is going to get just like the "don't make bad remarks about the sponsoring vendors" one, but this has to be done.

i don't remember much about my electrical engineeing classes, so i couldn't really comment on the PB. but i have spent a good part of my career designing aircraft structure and this bar is sn*ke o*l. the previous comments about this thing not being triangulated are right on. the load from the suspension will seek the stiffest path, and this relatively wimpy truss thing (compared the shell) ain't it. and how many rubber bushings are there between the appplied suspension loads and this bar?

and don't mr. moderator pull this comment or thread. the people making claims about these products are relying on NOT having professional engineers reading these forums and commenting. they are commiting fraud if they just make up stuff about their product without any scientific basis.

i DARE the guy making the claims about this bar to show us a finite element model of the rear of the car, reasonable hand calcs. of the loads and deflections, free body diagrams, or even measured deflections. i'll bet none of the above were done.....so put up or shut up and sell this thing as a nice shiny object to impress the unknowing.

 

Another thing, wouldn't that rear stress bar be bolted into the interior plastic behind the seats? How is that going to help make the car more rigid and improve handling if its just bolted into the plastic panels?

 

>>and don't mr. moderator pull this comment or thread. the people making claims about these products are relying on NOT having professional engineers reading these forums and commenting. they are commiting fraud if they just make up stuff about their product without any scientific basis.
>>
>>i DARE the guy making the claims about this bar to show us a finite element model of the rear of the car, reasonable hand calcs. of the loads and deflections, free body diagrams, or even measured deflections. i'll bet none of the above were done.....so put up or shut up and sell this thing as a nice shiny object to impress the unknowing.
>>

I'm not sold on any of the bracing products yet, either, but... engineers shouldn't start quoting the law, either...

Fraud can only be proven by you, and it must be done so both clearly and convincingly. With regard to the rear stress bar it is the obligation of you to prove these allegations by clear and convincing evidence. The burden of proof is yours, not his. Pilo is under no requirement to disclose ANY engineering information and shouldn't have to...

Next, someone will suggest that defaming someone on one of these boards is tantamount to slander.

Any reasonable person should be able to look at this part and come to their own conclusions about it. Although I will say that there are no details anywhere to be found about the install, where it's connected, etc...

On any vehicle with unibody construction, I find it hard to believe that bracing doesn't help, regardless of how torsionally stiff the chassis might be... High stress applications like racing of any sort, rockcrawling, etc. subject chassis to forces that are hard to duplicate in a lab (at least not in a tuning shop, where limited budgets would make subjecting every vendor offering a new part a ridiculous requirement to place on them). When rockcrawling in my unibody Jeep Cherokee (a 1997, which had one of the stiffer chassis they built), you would have been AMAZED by how much the chassis would twist in certain spots on a trail - enough to not allow my rear hatch to be opened or shut.

I'd like to see pics of the install...

 

Oh, and here's a fun link to a study done on a unibody chassis...

Unibody Vehicle Chassis Stiffness Study Using Abaqus

Some quotes:

"The unbraced deformations are clearly much higher. On the front edge around 75% higher, and about four times higher on the cross member. Tower displacement went from .9 to 2.1 mm, and increase of over twice."

"The benefits of the strut tower brace seem to be validated. Chassis flex at the key suspension points went down considerably. Many experienced drivers claim to be able to feel the stiffness increase in a chassis when such a brace is added, and from my results it seems as if that may be possible."

Of course, it's just one model... and one experiment. Like the author says, it warrants further investigation.

 

under heavy race usage, I am certainly going to use that....
A friend of mine didn't put strut brace for the rear in his E46 while he was racing in PDX and it turns out that the chassis is no longer flat.... it twist by 3-5 mm(between left and right!)
I better spend 180$ to make sure it won't happened


daniel-

 

You dont need to spend $180...here's a similar bar for a lot less money

Stress Bar

$180 is Quite a bit overpriced considering the market is charging 10 times less than Pilo...maybe the sticker cost $170 to make.

 

There are different forces acting in many different directions to tear yur car apart. A bar connecting your shock towers, front or rear, will counter one of these directions: the top ends of your shock toweres will no longer be able to move toward or away from one another. Make sense? A simple non-triangulated bar will at least keep the motion paralel. And that IS better than nothing. A triangulated rear bar has the additional benefit of helping to keep the towers SQUARE to one another. So that's even better. But I seem to remember PILO mentioning a possible triangulated bar in the future. It's Kinda like any other mod. There is probably a more complicated and therefore more costly way to do it better.

Just my perspective

 

This seems to NOT mount to the Strut Towers... which lends itself to become interior "jewelry", like wearing a Rolecks!

What if you removed the backseats and bolted this bar to the actual body of the car, would that help out more?

 

When designing brace products I'm sure there are many theoretic and practical considerations and concerns.
Some things that cross my mind-
I am and will continue to be open minded about the Pilo Rear strut bar- until it is clearly evident from evidence presented that this bar does not offer benefit for the MINI.

Practical considerations- Cost: While it would be nice to have complicated designs with triangulation and multiple attachment points, this would possibly increase cost of materials/design costs/manufacturing costs which also might result in heavier weight and more bulk. (although a clever design might still be possible).
Simplicity:-Simple is nice-easy to install, helps enough (albeit has limits based on design), reasonable on weight, looks nice, doesn't take up too much space or conflict with other things in the boot area.

Attachment points- seems to me that any design for a strut brace would be limited by the place where such a brace can be easily bolted on to the MINI's rear chassis/rear towers. In some cars this is easy to find. So what are we bolting this Pilo brace to? That is why I would be interested in seeing what the instructions look like-not only from a ease of installing viewpoint but does it make sense how this works. Bolting the brace to the metal frame would make the most sense if it could be done. Much like the front tower strut brace.

Personally I am not bothered too much that the brace isn't really beefy and triangulated. If I was jumping my MINI and rock crawling I'd go for lots of structural reinforcement but if I was going for a measured improvement in bracing over the stock set up then my expectations would be more subdued.

Also-can we keep this discussion going in a civil tone with constructive comments and suggestions please?

 

a way to visualize cornering forces applied to the chassis is to break them down into vertical and horizontal componenets...mull this over:

Horizontal forces are delivered from the tires' contact patch and through the rear control arms into a point near the center of the chassis. The triangles formed by the tire patch, control arms tie down point and rear trailing arm are very stiff with a slight bit of movement allowed by the rubber bushing at the traling link attachement tot he chassis just forward of the wheel. Horizontal forces are sufficienty contained and have little afffect on torsional stiffness

Vertical forces are transmitted to the upper tower, a part of the chassis, located about 4 inches above the top of the tire and inboard about 8 inches from the tire centerline. In hard cornering, or over uneven surfaces, one wheel might have an upward force component while the other a downward. This tends to twist the rear of the chassis and is contained by the torsional stiffness of the structure composed of the towers, their attachment to the chassis and the structure of the chassis between the towers and forward to the next most stiff refernce point. If all you did was connect the top of the towers with a stiff link, there would still be twist, but the two towers would not be able to pinch together or pull apart (a mode controlled by the control arms anyway). If you start to move the attachment point away from the tops of the towers, you are adding more potential for flex, even for the horizontal mode. The vertical force is simply not addressed by this horizontal strut. Imagine in a conceptual extreme case that the left tower was pushed up 2 inches and the right pushed down two inches; the horizontal bar would simply tilt since nothing is preventing it from rotating. On the other hand, if the ends of the bar had diagonals connected to the center of the chassis (at the point where the contols arms are terminated) you would have a tension/compression element resisting the twist.

 

From my observation from Dinan Strut bar, it has tilted angle and triangullar braces on the mounting parts. It does make sense when I read to jlm post...


daniel-

 

>>This seems to NOT mount to the Strut Towers... which lends itself to become interior "jewelry", like wearing a Rolecks!
>>
>>What if you removed the backseats and bolted this bar to the actual body of the car, would that help out more?

From what I remember from the posts during developement, the Pilo bar does bolt to the shock towers... just not at the top. I believe it REPLACES the stock seat latching points with his own steel brackets which include mounting points for the bar,and bolt throug the plastic to the steel... shock towers.

However, this hasn't been well publicised, and I'm sure it would be helpful for everyone if an instal FAQ were written.

 

>>and don't mr. moderator pull this comment or thread. the people making claims about these products are relying on NOT having professional engineers reading these forums and commenting. they are commiting fraud if they just make up stuff about their product without any scientific basis.

Just a note - posts don't get pulled because they are challenging a vendor on the site...They get pulled when they turn personal and get off-topic. Whenever we can we'll try to pull out the personal name calling and return the post for discussion. Even heated discussions like this one is sure to be must follow the site posting guidelines.

Now...returning to our regulary scheduled heated discussion...

Mark