[F87source]

Originally Posted by M Fifty

Noting that this isn't intended as an attack on your purchasing preferences, judgement, political affiliation, sexual orientation, nationality, self identified technical expertise, or prose style, lets try again:

Nope. 6 bolts. Trust me. If you really want to you can turn the locking tabs on the trim covers and remove them to give yourself more room to get at the 4 rear bolts.

As to scratches, the floor is generally a good place to rest it, as the shape means that provided you put it down right way up, the CF bits are kept away from any possibility of scratches. Or, it's possible to lean it against a wall if using the floor takes up to much space. HTH

1) Yes I guess you can do it that way to avoid using spring compressors, I always like pulling the entire shock body. Cost is always part of the consideration if you are deciding on which option, especially when effectiveness is debated. Don't forget cutting of the fenders may also be involved.

2)

- First of all the m235ir and other m cars besides the m2 doesn't have the strut tower mounting points for the corner braces, so it isn't about just adopting it you'd have to change both the front support and weld in the tower support.

- Second you seem to forget the turner motorsports option is brand new, well before the time of the m235ir's creation. This means bmw has to use what they have on hand, and it is either the flimsy corner braces off the cabriolet or the better option that comes with an aluminium strut brace - i.e. the m4 solution. So obviously the choice was clear.

- Next you seem to have misread my response. I said the turner corner braces were much more effective than the carbon boomerang part, but what makes the bmw solution better is the aluminium strut tower brace. Which secures the strut tower from left and right movements as well as attach it to the firewall for forward and back movement.

The Turner solution inconjunction with a strut brace like this tubular steel bar: https://afepower.com/afe-power-450-5...nt-strut-brace

Or any carbon or aluminium brace of your choice if weight is a concern. Will now give even better left and right bracing than aluminium, as well as now giving better bracing forwards and back - because you have 2 items bracing in this direction - the tubular steel stock brace + the corner braces. Then in terms of wheel house bracing the turner corner braces do a better job because they are bolted to the wheel house region by more connections thus reducing the leverage and reducing flex. Look at the install of the oem brace and see the amount of flex when you have such a large unsecured arm. You cannot beat physics regardless of the material.


Lets also not forget upwards movement as the towers flex. The turner braces will help resist this better as they are more rigid from being bolted in in more places, plus there are braces on either side of the strut tower acting as a strap to hold it down. The aluminium brace acts on one side making it a weaker retention on one side. And the fact that you can see the large amount of flexing when it is being bolted down isn't a sign of immense rigidity, it literally makes it look flimsy, because these bolts aren't torqued to immense loads and it was still enough to deform the brace.


You also posted about the brace being able to rip out the threads and destroy the mounts in a crash proving its rigidity. No that is not proof of rigidity, that is proof of the immense shear, bending, and tensile strength of the carbon fiber vs. the thin sheet metal front support it is bolted into. Examine the details and types of forces better if you want to debate rigidity... Which also brings up the point, if the only 2 front mounting points are flimsy stamped steel how is it going to help transfer chassis stresses to the brace to improve rigidity? That's why it is better to bolt into many points vs. fewer.


Like I said before it's not the engineer's fault for not building everything up to top tier spec, it is the budget constraints. You seem to not realize this. Why do you think cars are still stamped steel and not carbon fiber? Why do you think M cars are based off of regular series cars and don't have their own custom chassis which would make performance way better? Why does the m235ir still share the same stock intercooler and cooling? Exactly budget.



- The original steel brace is an extremely simple V shape with a hollow tubular bar, it has one job movement towards the firewall and bumper. It weighs almost nothing. The aluminium brace is a solid one piece design, to get a solid design to have the same rigdity as a tubular design you must add thickness, as that will give more rigidity in the plane of thickness. Then you must designn it to wrap around the strut towers and brace the fire wall adding alot of material and size, this adds alot of weight. Then add in the strut tower brace, again a simple piece of tubular metal (aluminium) or carbon and since it only braces one direction you can make it as simple or complex as you want. The overall package will still be much smaller than the large aluminium brace. I doubt it weighs more than the aluminium brace.


In fact lets do a calculation:

M4 aluminium brace: 2.479kg (https://www.realoem.com/bmw/enUS/par...&q=31127855855)


M2 tubular brace: 1.685 kg (https://www.realoem.com/bmw/enUS/par...&q=51617378711)

Weicher's carbon brace under 750g as per: https://www.escape6.eu/wiechers-spor...f87--id462690/ (cheaper at ecs tuning)

2.436 kg is the total. So it is lighter...... That's not counting the additional pieces that are retrofitted for the alumium brace, you still have strut top reinforcement rings etc.