How good is the strut brace? Performance wise?

[m3f_das borgen_362acec4fe]

A local here runs 900 #/in front springs on his race car





No shock tower cracking





1100 spring in the back.... Koni shocks

[m3f_ASC FTL_ccd289122e]

A local here runs 900 #/in front springs on his race car





No shock tower cracking





1100 spring in the back.... Koni shocks



Is it a track only car?



i think it's the potholes and huge camber changes between gutters and driveways that do these towers in..



as well as plowing into curbs!

[m3f_OahuMPower_17503f01cd]

Oahu - were you running some really brutal springs? I'm scared all over again!





nothing crazy... OEM for a while, 500 Eibachs on Konis (GC Track/school), and now 600 Hypercos on ASTs

[m3f_Richardspe_ff9fba485e]

Interesting. I wonder if it's a case of metal fatigue which would cause a brittle fracture to the fatigued area. Either way, that's not a good thing to have.



Interesting. I wonder if it's a case of metal fatigue which would cause a brittle fracture to the fatigued area. Either way, that's not a good thing to have.



Fatigue failure and brittle fracture are pretty much unrelated failure modes.



Brittle fracture is a catastrophic sudden failure of a material (usually steel) when subjected to stress, and the temperature of the material is below the reference transition temperature where there is little elastic or plastic deformation.





That picture looks like a fatigue failure mode. Too many cycles, the material hardens, then gets softer, then fails.



Anyway, it isn't that common. I mean BMW made what, about a million E36's worldwide? I've got the Motorsport bar, and don't really worry about it. I remember talking to Steve Dinan and Tom Milner at an IMSA race at Watkins Glen, and the both said that if a bar has a hinge, it's eye candy, not functional.



And the problem with the Mini's was pretty much a R50-53 problem. (first gen of the new Mini) But it's still not a bad idea on the R55-57's (second gen)

[m3f_das borgen_362acec4fe]

Is it a track only car?



i think it's the potholes and huge camber changes between gutters and driveways that do these towers in..



as well as plowing into curbs!



I said race car...didn't I?

[m3f_OahuMPower_17503f01cd]

I remember talking to Steve Dinan and Tom Milner at an IMSA race at Watkins Glen, and the both said that if a bar has a hinge, it's eye candy, not functional.



and dinan still made their strut bar with 2 hinges in it? That doesnt make sense

[m3f_JPoland_e17b491a3d]

Well Nick, I just went and looked and you are right there are no channels to accommodate the ridges.

This may just be me trying to defend my purchase lol but I don't see that as a problem. If anyone disagrees with the following reasoning then by all means I'd like to hear it.

If the brace accommodates the ridges then the goal is to get it to sit flush with the tower surface (ok pretty obvious). However, that then means that the area immediately around the bolt holes is not likely receiving much pressure on top from the brace. If that is the case then the brace is doing very little if anything to prevent any crack formation or propagation from occurring at the holes.

Since the holes are the most likely spot for a crack to initiate (basically any hole or discontinuity in a surface like that is a stress riser, think of a chip in a windshield is highly likely to be where a crack starts or quickly propagates to), not having surface to surface contact there is not ideal.



So having a brace that is specifically made to make sure that area is getting the most surface contact, at least statistically, could do more to prevent a failure than a brace which attempts to cover as much of the tower as possible.



All that said, using that logic I still think it may be possible to improve the design principal of the mason brace, at least in an ideal world where every strut tower is identical.

If the brace was contoured to accommodate the ridges in the tower and come very close to the surface of the tower but still use the current design idea of sinking the area around the bolt holes to ensure those locations are the points of contact all the time, you would get the best of both worlds. You would have the sandwiching of the area around the bolt holes (the most likely place for failure to initiate from) and if the surface of the tower deflected slightly it would come into contact with the brace and stop deflecting.



That is idealistic though and to machine something like that would be WAY too costly. The tolerances to get the gap between the tower surface and the brace to be within the elastic deformation range of the metal would be tough especially since there is going to be differences from car to car. This is why I suspect the Mason brace is designed to protect against the most likely points of failure.



Seems in depth I know and maybe that is just how I'm justifying owning the brace but if my logic is flawed then I want to know. I have no problem admitting that I purchased a product which possibly is not serving the purpose I had intended and actually, I would want to know.

[m3f_Roland H_da3d16ded4]

and dinan still made their strut bar with 2 hinges in it? That doesnt make sense



Makes tons of sense. They're an eye-candy company that also makes some performance parts.

[m3f_slickfast_363624089e]

Fatigue failure and brittle fracture are pretty much unrelated failure modes.


Brittle fracture is a catastrophic sudden failure of a material (usually steel) when subjected to stress, and the temperature of the material is below the reference transition temperature where there is little elastic or plastic deformation.


That picture looks like a fatigue failure mode. Too many cycles, the material hardens, then gets softer, then fails.


Anyway, it isn't that common. I mean BMW made what, about a million E36's worldwide? I've got the Motorsport bar, and don't really worry about it. I remember talking to Steve Dinan and Tom Milner at an IMSA race at Watkins Glen, and the both said that if a bar has a hinge, it's eye candy, not functional.


And the problem with the Mini's was pretty much a R50-53 problem. (first gen of the new Mini) But it's still not a bad idea on the R55-57's (second gen)


I didn't really mean brittle fracture then, I apologize for the confusion. I meant fatigue failure (the brittle bit was about how it yielded). I'm an aero engineer, my language of failure modes is a bit rusty so thank you for the correction. That's something I should know thoroughly.


It's not that common, but if it wasn't an issue over so many different chassis I probably wouldn't be talking about it. What about E46 subframe mounts tearing completely out? Rear strut mounts in E36s? R50-R53 strut towers deforming? E31 rear strut mount failures? Z3M Coupe trunk floors tearing? It's all just conjecture and observation, but I feel like (although usually not severe enough to call for a recall), BMW constantly makes the mistake of underestimating the amount of material needed to sustain normal loads that the car will experience. Or maybe it's just that they're designing the cars to withstand the first 50k miles. Anyway, BMWs overall are extremely well-built cars, but they aren't without their glaring problems. Sigh. /rant


Edit: the one positive thing is that they do seem to be learning from all this. As you said the R55-7 generation hasn't been having any problems that I've seen, and the E9x generation doesn't seem to be having those problems (that I know of). So hopefully my complaint is short-lived.

[m3f_JPoland_e17b491a3d]

It does stink that even the performance division of a company commonly regarded as producing well engineered cars made for being driven enthusiastically still knowingly leaves some engineering undone on the table. They too fall subject to the approach that the majority of the cars they produce will not be driven in a way that will compromise the potential weak points thus they will be able to cut some costs by stamping thinner metal or whatever the case is.



Still, given the cost and performance potential of the car (as well as my current income :lolhit: ) I am willing to deal with the weak points in order to be able to enjoy the rest of the car.

[m3f_ASC FTL_ccd289122e]

I said race car...didn't I?



:raspberry:



Im fighting off a sore throat, gimme a break :shifty:

[m3f_Richardspe_ff9fba485e]

Hey, eye candy sells too.

[m3f_OffensiveDriver]

I'm no engineer but when I decided the lightweight BMW motorsport strut bar was too expensive, one of the few bars that looked like it made sense was the UUC Strut Barbarian.



http://www.uucmotorwerks.com/STB/STBE36_pics/Img_6746.jpg



it looks like it's on sale.

[m3f_ASC FTL_ccd289122e]

I'm no engineer but when I decided the lightweight BMW motorsport strut bar was too expensive, one of the few bars that looked like it made sense was the UUC Strut Barbarian.



http://www.uucmotorwerks.com/STB/STBE36_pics/Img_6746.jpg



it looks like it's on sale.



It's a nice piece but it doesn't allow access to adjustable shocks.



I'm a fan of the cheap steel one, and will probably one day get one.

[m3f_Roland H_da3d16ded4]

I'm no engineer but when I decided the lightweight BMW motorsport strut bar was too expensive, one of the few bars that looked like it made sense was the UUC Strut Barbarian.



http://www.uucmotorwerks.com/STB/STBE36_pics/Img_6746.jpg



it looks like it's on sale.



It's prone to stripping and cracking. Buyer beware.