The Ridge!

The Ridge!

"On April 29th 2022,  I launched a crowdfunding project to create a new 1:1 E46 M3 CSL carbon diffuser option on the market. 30x members backed the project in a few days 🙏

In this special series written in collaboration with René at, I document the entire ideation, development, master & negative mold production process along with my unboxing impressions and final fitment

This journal entry documents the backstory to this successful crowdfunding, and why it matters."


Suppliers of 1:1 CSL carbon diffusers are none existent as of today or others just plain don't have the tooling & data to do it right.

René @ CarboProject has a CSL diffuser with a slight design change that smooths out the ridge in between the carbon and painted section to avoid IP issues with BMW in Europe.

The ridge-less design


It was introduced a year ago and was fitted by a few members of EuroConnex. 

He backed off on producing more of these due to packaging issues on the initial batch and went back to the drawing board. The packaging issues were fixed - but his production was backlogged with other projects.

The 1:1 Crowdfunding Project

I was finally able to convince René @ CarboProject to consider the project and create some time in his production schedule for something new.

The project involves opening up a new carbon fiber mold for the production of this design instead of his older slightly different design to avoid IP issues with BMW in Europe.

I can go into little details about this - René will not simply be using an OEM CSL diffuser to create a negative mold.

It's a level higher in terms of precision, and it will support the creation of a durable mold that should allow the E46 M3 community to have access to an OEM like CSL diffuser for years to come

New Mold to OEM Precision

What I can tell you is he had already produced a prototype way back in the days and settled on making the slight design change mentioned above.

What differentiates this new project from any other CSL diffuser currently available will be it's exact design and fabrication replica to the OEM BMW M3 CSL diffuser in every single detail, cut and carbon process.

The carbon process is the same as OEM: Pre-Preg Carbon cured in Autoclave using the original 1x1 plain weave as used by BMW M on the CSL. 2x2 is optional.  


The learnings from the initial batches

This project will incorporate many of the learnings from the initial batches of the previous CSL diffuser of René.

1. Packaging

More foam, more bubble wrapping, more paper, thicker cardboard boxes. It increases shipping & packaging prices a bit.

It's a no brainer trade off considering 1/5 of the initial diffusers were trashed UPS and incurred some form of damages to the paint, carbon or mounting clips.

2. Color Matching is still available

Color matching remains available and is very affordable alternative to getting it painted locally as it fits within René's fabrication process.

The paint line will be dictated by the ridge unlike his previous design which left more leeway.

3. Ready-to-Paint Primered

This is for the guys that want complete controle over their paint process: preparation, paint line, color matching and paint finish.

Up next: taking you behind the scenes on the various steps to the master mold creation process. 


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