I was thinking about this as I have the M7 strut brace in my car. I understand that the strut brace prevents the strut towers from pushing up, but what about the rubber strut tops? How does it stop them from pushing up and cracking? Wouldn't the added protection on the strut towers just make the rubber strut tops more susceptible to cracking? If you go over a bad pothole wouldnt the shock transmit more to the rubber piece since the metal towers are protected?

 

I don't know how it works, but I can tell you it does work. My 2006 MCS has had an M7 bar on since new & at 69,000 miles I have no mushrooms. IMHO money well spent.

 

A strut brace is not really designed to stop the mushrooming but it can help provide support to the top of the strut tower. The amount of benefit depends on the strut brace design where it mounts to the tower. Some braces provide a lot of support and some do not. The M7 brace does provide a lot of support for the strut tower because it utilizes a thick plate at the top of the tower.

The strut tower can be better supported from underneath the top of the tower. For example, adjustable camber plates utilize a thick plate underneath the top of the tower.

The M7 strut brace will not help the top rubber bushing of the strut. The rubber will still crack/tear/rip. Again, adjustable camber plates eliminate the problem by replacing the rubber bushing with a strong bushing, usually steel.

Another option (rather than adj camber plates) to resolve both issues (mushroomed towers and cracked rubber bushings) is to installed fixed camber plates. They have three benefits. They increase the negative camber by 1.25 degrees, use tougher rubber, and have a stronger top plate.

 

None of the strut tower braces or plates will prevent the rubber on the strut mounts from breaking or cracking. The only way to prevent that is to replace them with camber plates.

The M7 strut brace is the best at preventing mushrooming cause it has the complete plates on the ends. The thickness of the plates keeps the metal in the mount from bending and being mushroomed. The reinforcement isn't going to cause any more force to be transfered to the rubber.

 

thanks alot. thats what I figured.