E86 Front Triangulation Braces Retrofit

[heinzboehmer]

Thanks everyone! Very excited to see this recreated on other cars.

Also, added a cost breakdown and weight breakdown (still incomplete) at the end of the doc.

[Casa de Mesa]

Heinz FTW!! This is incredible. Will dive into this in detail once this work week is in the rearview.

[discoelk]

Hell yeah. Thanks. More stuff to distract me from my actual project car. Haha.

[Obioban]

Excellent!

Can vouch that front end triangulation was one of THE best mods I've done to this car. And, only better-- zero downside.

[bigjae46]

Hell yeah! This project will be much easier for me since my car is not a street car. I've deleted the heater core and wipers. As I've mentioned previously, I think the base mount is a great candidate for a forged carbon part. Not too difficult.

https://nam3forum.com/forums/forum/main-forum/member-build-journals/6890-the-red-drift-machine?p=320337#post320337

This is a great video on compression moulding

https://youtu.be/25PmqM24HEk?si=nhcX4nBLUswcC3cl

For the strut towers, I am thinking about also compression molding the OE strut bar ends and bonding slightly longer studs so I can bolt two bars to the same plate. I am concerned with putting extra loads into a cheap cast aluminum part. Then make carbon tubes from this site below. They have rod ends that can be bonded on. I like making my own parts but they have the layup optimized which is much more important in a load bearing part.

DragonPlate | Engineered Carbon Fiber Composite Sheets, Tubes and Structural Components | Made in USA

[karter16]

This is just incredible. It's been so so cool following you through this project. I had a browse through your documentation and it's so clear and thorough! A+ job all round on this!


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[0-60motorsports]

heinzboehmer Thanks so much for doing this and posting up the details for the community.

[heinzboehmer]

TL;DR Everything needed to recreate this project can be found here: https://drive.google.com/drive/folde...KH?usp=sharing

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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:

1. Increased torsional rigidity (and all the good things that come with that).
2. Increased grip mid corner, since there is less camber loss when the front tires are loaded.
3. 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.
4. Decreased NVH, since the chassis can deflect (and thus, creak) less.

There are also a couple fun side effects that come with this:

1. The comprehensive install results in a net decrease in weight (roughly 2 lbs), when compared to the stock parts.
2. Since the replacement cabin air filter housing and firewall plug parts are WAY lighter than the stock ones, you get significantly more intake noise in the cabin.

All documentation and design files can be found here: https://drive.google.com/drive/folde...KH?usp=sharing

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