TL;DR Everything needed to recreate this project can be found here: https://drive.google.com/drive/folde...KH?usp=sharing
Sharing my design for a street car friendly way to triangulate the front strut towers to the firewall. This is inspired by the stock triangulation present on the E86 and newer BMWs. I also have to give credit to Slon for pioneering this concept on the E46 chassis and proving that it was worth pursuing.
I'm sharing this completely for free and in the open source spirit. I expect no one to profit off of this and just ask that you share any modifications/enhancements/tips/feedback if you go through with installing on your own car.
This should be compatible with both RHD and LHD cars, but I've only tested on my LHD car, so can't say for certain. If anyone with a RHD car wants to recreate this, I suggest 3D printing the custom parts out first just to check fitment.
Some pics of the installed braces:



The main design considerations were "OE-ness", engine serviceability and crash safety. To achieve this, I based the design around the stock E86 triangulation braces and designed the rest of the components to work with them.
There's a good amount of discussions regarding the benefits of this type of bracing in other threads, but to summarize, these are what I consider the main benefits:
I strongly suggest you read the entire documentation before doing anything else. I know it's long, but there are a lot parts involved and a lot of places to go wrong.
For more details and an ongoing discussion of the project, refer to this thread: https://nam3forum.com/forums/forum/m...694#post298694
NOTE: This project is not fully finished. I still need to wrap up the design of the modified cabin air filter housing and fill in some sections in the documentation. I'll get to these tasks soon and update this thread when those are finished, but figured I would share now in case anyone wants to replicate what already exists.
Sharing my design for a street car friendly way to triangulate the front strut towers to the firewall. This is inspired by the stock triangulation present on the E86 and newer BMWs. I also have to give credit to Slon for pioneering this concept on the E46 chassis and proving that it was worth pursuing.
I'm sharing this completely for free and in the open source spirit. I expect no one to profit off of this and just ask that you share any modifications/enhancements/tips/feedback if you go through with installing on your own car.
This should be compatible with both RHD and LHD cars, but I've only tested on my LHD car, so can't say for certain. If anyone with a RHD car wants to recreate this, I suggest 3D printing the custom parts out first just to check fitment.
Some pics of the installed braces:
The main design considerations were "OE-ness", engine serviceability and crash safety. To achieve this, I based the design around the stock E86 triangulation braces and designed the rest of the components to work with them.
There's a good amount of discussions regarding the benefits of this type of bracing in other threads, but to summarize, these are what I consider the main benefits:
- Increased torsional rigidity (and all the good things that come with that).
- Increased grip mid corner, since there is less camber loss when the front tires are loaded.
- Increased steering feel, since more force from the tires (i.e. feedback) is going into the steering rack/wheel instead of going into deflecting the strut towers.
- Decreased NVH, since the chassis can deflect (and thus, creak) less.
- Fun side effect: the replacement cabin air filter housing and firewall plug parts are WAY lighter than the stock ones, so you get significantly more intake noise in the cabin.
I strongly suggest you read the entire documentation before doing anything else. I know it's long, but there are a lot parts involved and a lot of places to go wrong.
For more details and an ongoing discussion of the project, refer to this thread: https://nam3forum.com/forums/forum/m...694#post298694
NOTE: This project is not fully finished. I still need to wrap up the design of the modified cabin air filter housing and fill in some sections in the documentation. I'll get to these tasks soon and update this thread when those are finished, but figured I would share now in case anyone wants to replicate what already exists.
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