"These build journal entries are part of a Special Series on my impressions of the S85 OEM+ Carbon Plenums. 

In this entry, I cover the background development to the S85 OEM+ Carbon Plenums and document my unboxing impressions of this clever design I've used to great effect on my V8 M3."
- Matt

The Original Design.

The OE+ S65 carbon fiber plenum is the original design that sowed the idea to EuroConnex. I did an initial group buy in the Summer 2020 and it eventually snowballed into the launch of EuroConnex in Winter 2021.

I have been running his S65 carbon plenum since Fall 2020 and still love it to this day.  

Unboxing the V10 variant.

It was only natural I fit the V10 carbon plenums to my M5. I received these 2022 before the end of Winter. They came well packaged and without any damages during shipping from Germany.

The S85's Carbon Plenums are developed with the same foundational OEM plastic lower base.

The lids are replaced with pre-preg, autoclave'd carbon fiber lids. They are much thinner than the standard ABS plastics, providing the enhanced sound we're all looking for.

I love the box due to its proven design: these were initially developed around 2007 in Germany.

The lower half being Genuine BMW ensures an OEM fitment. It also ensures no mission critical failure to trumpets which have happened on some carbon fiber airboxes and plenums for the S54 and S65.  

René goes to great lengths to refurbished the Genuine BMW plenum core. It is fully cleaned and new black upper clamps are fitted for a clean appearance. 

Customization Options

As the S65 community started adopting the product en masse, we provided feedback - and he listened. 

René has improved the product and started offering various new customization options: new weave patterns, finishes, badges & stickers and increased sound options. 

Continuous Improvements.

Most importantly, René has improved the product design with new processes to bond the upper carbon lid to the lower Genuine BMW base of the plenum to eliminate cracking & ungluing risks. 

My Specs.

My S85 Carbon Plenums are further proof to René's relentless pursuit of perfection. I opted for the Export Version in Naked aesthetics: no badges or stickers. As of 2023, all Carbon Plenums are "export" sound variants.  

The Matte clear coat's sheen level was specifically blended to match the Sealed Carbon Intakes that I first fitted to my S85. 

My engine bay should now be proper.

Up next: I'll discuss my driving impressions, provide more installed pictures in the next entry and I hope to get sound clips.