[M4Lou]

Originally Posted by USMC_Sam

The closer they are (laterally) on this chart the less the severity of corrosion. AL and Carbon (graphite) is almost as worse as it gets.

https://en.wikipedia.org/wiki/Galvanic_series

As for stiffness, I'm assuming torsional stiffness is whats needed. Having 5 mount points, like the CS style, brace only offers marginal increase in stiffness with a 1 lb (ish) weight adder (solid AL vs tube/box steel).

I agree with M4Lou, If I change/upgrade - I want it to "be" an upgrade. Not just some bling.

Good pick up Marine. I can see why my old muscle car buds would fuss about aluminum and stainless.

My guess is that a lot of the CF braces have some type of "space age" epoxy (lol) that attaches the strut mounting points to the CF struts.

I'm waiting on someone to pimp the Motech units. They look like poor man's version of the Fall-line/fallout boy deal. I wonder if they are stiff/well made (the motech unit).

I am glad this thread has some legs. There are TONS of strut braces and quality is unknown w/ 75% of them...

[USMC_Sam]

Originally Posted by M4Lou

Good pick up Marine. I can see why my old muscle car buds would fuss about aluminum and stainless.

My guess is that a lot of the CF braces have some type of "space age" epoxy (lol) that attaches the strut mounting points to the CF struts.

I'm waiting on someone to pimp the Motech units. They look like poor man's version of the Fall-line/fallout boy deal. I wonder if they are stiff/well made (the motech unit).

I am glad this thread has some legs. There are TONS of strut braces and quality is unknown w/ 75% of them...

To be fair, bonded joints using composites is (when done correctly) strong as shit. Composites are great with distributed loads, but with point loads, special consideration is needed.

I have seen any strut braces from MoTech yet, can you share a link?

I'd argue that most aftermarket stuff has no performance benefit and are all for ascetics.

S/F

[M4Lou]

[USMC_Sam]

Originally Posted by M4Lou

I doubt this Motech brace is much of an upgrade. AL is ~1/3 the density of steel but steel is 3x stiffer. The geometry of this bace leads me to believe is not much (if any) stiffer. I didn't crunch any numbers, just going off my engineering judgement and experience.

[SwankPeRFection]

The BMW engineers who made the CSL one are laughing at all the aftermarket junk out there that doesn’t stiffen up shit. 😆

[forcefed]

Originally Posted by SwankPeRFection

The BMW engineers who made the CSL one are laughing at all the aftermarket junk out there that doesn’t stiffen up shit. 😆

But it looks purty

[M4Lou]

Originally Posted by USMC_Sam

I doubt this Motech brace is much of an upgrade. AL is ~1/3 the density of steel but steel is 3x stiffer. The geometry of this bace leads me to believe is not much (if any) stiffer. I didn't crunch any numbers, just going off my engineering judgement and experience.

Yeah - just looking for "as stiff" and lighter/better looking. Heck - even the cross brace on my X3M is aluminum and looks better than the crow/bar on the M4.

[gc.g80brg]

Originally Posted by Mapper

Karbonius.
Black friday price.

nicest strut available ! I would color match the silver part to the car.

[Tall Tom Cruise]

I have the CSL one. Fun fact, the OEM CSL brace could be had for $900 from PaddleShifterz last year for a few months (luckily I bought it then)... now it is $3k on IND lol.

It was a nice, brief window of time. Then BMW starting asking for VIN #'s when people wanted to order a CSL brace.

[USMC_Sam]

Originally Posted by M4Lou

Yeah - just looking for "as stiff" and lighter/better looking. Heck - even the cross brace on my X3M is aluminum and looks better than the crow/bar on the M4.

Crowbar! haha. Haven't heard that one yet

[USMC_Sam]

Originally Posted by Tall Tom Cruise

I have the CSL one. Fun fact, the OEM CSL brace could be had for $900 from PaddleShifterz last year for a few months (luckily I bought it then)... now it is $3k on IND lol.


It was a nice, brief window of time. Then BMW starting asking for VIN #'s when people wanted to order a CSL brace.

ML Perf. is ask $2k. Not vastly better than IND and certainly not as good as your deal. I've seen some on ebay for about 1k but there is always uncertainly there.

https://www.mlperformanceusa.com/pro...wYTmlrfrt56PnA

[Mapper]

Originally Posted by gc.g80brg

nicest strut available ! I would color match the silver part to the car.

Thanks for the suggestion. I like the idea and will implement. Thanks

[Info@mad-us.com]

Originally Posted by Tall Tom Cruise

I have the CSL one. Fun fact, the OEM CSL brace could be had for $900 from PaddleShifterz last year for a few months (luckily I bought it then)... now it is $3k on IND lol.

It was a nice, brief window of time. Then BMW starting asking for VIN #'s when people wanted to order a CSL brace.

That's insane. 2-3 k for a strut brace you better be a track star.

[Mapper]

I inquired with ryan and INd and karbonius on these speicfic questions on strength, torsional strength and galvanic properties.. their rsponse is
"there is an adhesive used between the two materials which will prevent corrosion from happening between the two materials so not a concern "
and
" the brace is just as strong if not stronger than the cast brace from BMW OE CS.

Shrug

[USMC_Sam]

Originally Posted by Mapper

I inquired with ryan and INd and karbonius on these speicfic questions on strength, torsional strength and galvanic properties.. their rsponse is
"there is an adhesive used between the two materials which will prevent corrosion from happening between the two materials so not a concern "
and
" the brace is just as strong if not stronger than the cast brace from BMW OE CS.

Shrug

Mapper thanks for asking and yes, shrug. I'm not shocked their answer is vague, why would they share deign details for others to copy.

If there is no fasteners then its obviously bonded which can still be an electrolytic path, albeit not as much of a conductor and therefore has slower corrosion rate.

Strength and stiffness are 2 different things and often confused. They aren't even the same units! (force/area vs force/distance)

[SwankPeRFection]

The torsional strength of the Karbonis CSL copy can easily be tested by taking off just the front screws on the radiator support and then trying to lift and twist it at the corner in the front. If it moves at all, then its torsional strength isn’t as good as the BMW one. That’s where the CSL design is a bit stronger because it has multiple points on engagement on the front and the front is also a solid long bar as opposed to a single bolt point, so technically, the front should twist as much torsionally when compared to the normal single bolt one. Now, if you change the material out to something that’s not solid, you might get back some of that flopping and twisting. I can tell you that obviously with the stock CSL ones, you can grab it at the front with two hands and you can’t twist it up and down on the sides when it doesn’t have the bolts in. It’s a solid box point.

[RUNSOK]

What about the kies carbon strut brace?? Is that functional or pure bling as well??

[M4Lou]

Originally Posted by RUNSOK

What about the kies carbon strut brace?? Is that functional or pure bling as well??

lol - idk!

It gets a pretty high mark on the ocular "bling-meter".

[Mapper]

https://youtu.be/mBMPvf8Joos?si=zgUOrC6hFA6gH7Yy


Aluminum 6061 fails before carbon fiber on the press.

[SwankPeRFection]

Originally Posted by RUNSOK

What about the kies carbon strut brace?? Is that functional or pure bling as well??

Considering they changed out flat mounting bars (effectively box beams meant to keep twisting at a minimum) to round mounts, yeah… in my opinion a downgrade for $1200 or whatever ridiculous amount it is. The front bar is meant to tie in the towers to the front a bit more to keep a boxed setup to try and minimize horizontal plane undulation a bit. Stock works fine, with the addition of the CSL side structural components incorporated into it, the load and reach of the forward-most mounting point was spread out more, effectively improving the undulation control more of the front end. In all honestly, I’ll take a flat and box beam designed one like the factory one is over a separate/split up mounting point one no questions asked. All the point points the Kies one has introduced had introduced variables into the rigidity of even the stock one. Not sure why they’d think it was better… outside of just better for their wallets when they sell them. 😆

[Wo-Wo]

I just had mine wrapped in the body colour as I couldn’t see the benefit of such a small weight saving vs the cost.

[davidmct-M3]

Originally Posted by Wo-Wo

I just had mine wrapped in the body colour as I couldn’t see the benefit of such a small weight saving vs the cost.

You could save the weight by adding slightly less gas in the tank - or having a smaller lunch. 😀