Are S65 Carbon Fiber Plenums worth it?

Are S65 Carbon Fiber Plenums worth it?

Short answer: yes. 

Long answer: it is the best driving experience modification on the M3 E9X.

I will stand by that - here's why. 

The S65 is a masterpiece: it is the heart, soul, and backbone of the E92 M3 - without, it may as well be another 335i with a few bits and bobs. 


Yet, Germans subdued the experience with sound deadening as it aimed at building a GT car first. As 15 years are now gone, we value the E92 M3 for its rawness hidden right below its coat. 

The Carbon Plenum is like seeing your wife moving from pyjamas to a dress: it exposes the flattering charms, fierceness of her character, and it does it with class. 

If you thought downshifts sounded good, you haven't heard anything yet. 

Unlike an exhaust system: a Carbon Fiber Plenum has no drone, no booming.

You control the madness with your right feet. 

It is forever grin inducing. 

If smile per miles was a true metric, this would top the charts. Fortunately, there are still things we can't measure in this world.

Whether you opt for CarboProject, Eventuri or Karbonius - this modification is, and always will be first and foremost about the driving experience. 

CarboProject's S65 Carbon Fiber Plenum

As a Canadian, I didn't feel like spending 5,000$ on a complete carbon plenum as I was mainly looking for the added induction sound, the motorsport carbon look and additional finish options that other OEM style carbon plenums didn't have. 

I started working my supplier network in Europe to find rare parts for my personal E92 M3.

I ultimately got introduced to René @ CarboProject. I wasn't ready for what came next. 

Learn more about the backstory to the Original German Connex here

I was in the 2nd batch of the original Group Buy and opted for the Export version with M Power stickers, Gloss clear coat finishing and OE screws top.  

Immediately upon unboxing the plenum as I received it from UPS air shipping in 4 days from Germany - one thing was evident. 

This was a quality piece. 

The CSL style 2x2 weave pattern is perfectly aligned. The M Power stickers are under the clear coat and you can see no visible specs or dirt in the clear - this has been wet sanded and polished, a quality touch. 

As I begun the installation and manipulated the plenum, I couldn't help but think the lid was flexible, and somewhat thin. 

I was a carbon fiber beginner back then. René introduced me to the concept of pre-preg & autoclaved carbon fiber: the highest level of carbon fiber construction quality. 

This will flex, but never crack. This is how the induction sound reveals itself in all it's glory - but I didn't know it yet. 

When I completed the installation, I went for a 250km drive down to Quebec City from Montreal. 

The entire driving experience is augmented. 

7-6-5-4-3, 3-4-5, 5-4, 4-5-6 - I couldn't stop doing it. My fingers were trigger happy, pulling the paddles at every occasion to discover new acoustics of the S65 across its entire rev range. 

The induction sound volume is drastically increased, and the sound characteristics are changed from the OE plenum. The CarboProject Plenum in Export Variant offers a deep, bassy tone from the S65 and lets in higher frequencies, slight vibrations - not to be confused with rattles. 

Continued Product Development

His carbon fiber plenum had initially been developed in 2007. As the community started adopting the product en masse, we provided feedback - and he listened.

The community feedback has helped improve the product with no-cost options such as Matte Clear Coat, Flat Top finish and the infamous Export version with the thinner, pre-preg, carbon fiber lid for improved induction noise. 

He's also went out of his way to offer custom CSL metallic grey stickers for @Gordon.M3 from CarbonExpress Inc

Learn more about the S65 Carbon Fiber Plenum and get the Connex with CarboProject GmbH here

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