Quote:
Originally Posted by F87source
If you compare the bracing for the wheel house I think the turner corner braces do a better job, and like I said before if you add in the aluminum brace then the whole m4 bracing package does a better job like I said before. However when you start adding in braces to the stock package then I believe it will match if not exceed the aluminum m4 brace in terms of strut tower bracing. Because you can chose a stronger materials with higher young's modulus for bracing, also strut tower brace are also positioned between the strut towers which is a more optimal position for transferring forces to the brace vs. the m4 aluminum brace which is off of the axis of movement meaning less efficient force transfer and in the direction where the brace is less reinforced (example if the towers flex together it is more efficient to transfer the forces directly into the brace where the forces are taken as compression in the direction the brace is the strongest, whereas a force coming in at an angle now acts as a shear force where there is little to support it.
The first m3 production date was April 2012...
Because nothing is perfect, every road car has compromises to meet road regulations and budget constraints. Why choose bmw? Because compared to other brands they have the least garbage put into their cars, fantastic tubular steel rear subframe, stainless steel tubular front subframe, all forged aluminum control arms and suspension components, and their fantastic quasi dry sump oil system. They just make garbage cooling systems and some parts like the bracing was cheaped out.
Like I said before this is why the aftermarket exists, to fix the crap left over by the OEM, because the aftermarket doesn't have to meet regulations nor budget constraints.
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Looking through RealOEM (which does have a number of errors), the earliest F8X (M3/4) came with a CFRP front brace with the part number 51618061631 (weighing 2.295 kg). This is listed as being used from 03/03/2014, which is inconsistent with the launch date of the various models. It is however listed as superseding 41008417085 (weighing 1.862 kg) but that is only listed for the M235i Racing from 11/01/2013.
This suggests that the brace predates the M3/4, even though the dates don't match.
So, there are now two scenarios:
1. BMW developed a chassis bracing system for motorsport use which they subsequently adapted for use on road cars for marketing reasons.
2. BMW developed a chassis bracing system as a marketing device, and subsequently used it for motorsport applications (but tried to make it even lighter and subsequently replaced it with a stronger item).
In the former case they will have prioritised effectiveness (so a trade off between weight and stiffness) while minimising cost. Using it on road cars was primarily a marketing solution (as said road cars would be unable to exploit the benefit), but it wasn't cost prohibitive and did actually work.
In the latter case, the marketing solution would have prioritised bling while minimising cost. While wishing to maximise the marketing potential, it would only ever have been used for motorsport if it provided a benefit that couldn't be realised more cheaply using other means.
In both cases, had just beefing up the corner braces yielded significant benefit, we could reasonably expect to see something like the Turner items on the M235i Racing (or just thicker versions of the wriggly tin items rendered in steel or aluminium), as there would be a compelling cost/benefit and weight reduction benefit compared to what they did come up with for marketing or motorsport use.
Having fitted the BMW supplied uprated parts on three cars now (R53, E46, F87), the difference can be felt in the steering while turning when going over camber changes and rumble strips at both low and high speeds. So, they are doing something.
If you can't feel any difference when using products from other suppliers, that doesn't mean they aren't making an improvement to your car's handing, but away from a track day with data-logging - how would you know?
But, they are significantly cheaper than BMW's solution, and - in concert with additional strut bracing - might result in a difference you can feel rather than only measure with data-logging on track.
HTH.
