E46 M3 Subframe Reinforcement Kits
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Staged Solutions.
These kits enable you to plan according to your use.
Top and bottom.
Plates aren't enough. Top side reinforcement is required to prevent long term catastrophic failure.
Front and rear.
A rear bar is not enough and does not address the weakest section of the chassis: the front upper subframe mounts.
Weld-in installation.
It's the ideal time to restore your underbody.
Build journal: Special Series
BMW M got sued over this.
Thanks to bright engineering minds, the technical understanding of the E46 M3's rear chassis weaknesses have evolved.
A comprehensive top and bottom, front and rear solution is recommended if you intend to keep your E46 M3 forever.
In this Special Series, I document my experiences on the Phoenix's restoration: the theory, the practice, the comprehensive solutions I reviewed, and the one I chose.
Enjoy,
- Matt / @m3_epoustouflant
Get your kit
If you want more [...]
level up to stage 3!
CMP offers bolt-in front and rear braces upgrades to further transfer loads across the chassis.
For street use, the front brace is an interesting "why not!".
It fits with the rear seats, still allows pass through, and does not compromise rear trunk space.
What was BMW thinking?
In this entry, I touch on the original design flaws, BMW's attempt to fix it and how they fell short until the M3 V8s came around.
The comprehensive solution I picked.
In this entry, I unbox Cayn's upper chassis reinforcement kit and chat about its engineering and technical features.
Need help?
Been there, done that.
Cayn @ CMP Engineering
The most efficient solution is often the most simple.
That's Cayn's moto.
The company began in late 2016 to answer the growing problem of E46 BMW RACP/subframe cracks and failures.
After discovering significant cracks in his low mileage E46 M3, he put his engineering abilities to the test and began developing what is now a comprehensive range of CMP reinforcement products for E46 BMW’s, new products for the M3 V8 and other M chassis.
