"In this Special Series, I document the backstory, unboxing and driving impressions of the S65 OE+ Carbon Plenum and the custom painted carbon variant.
In this entry, I pay homage to the original M3 V8 GTS.
I look back on the original GTS design, and unbox, inspect, install my take what the GTS should have had. Someone goes on a night run - with proper video clips to boot."
The GTS original.
BMW M has patterns, and at times not all. With the arrival of the M3 GTS, much was made of the stroked S65 up to 4.4 litres.
It was beyond what we had ever seen from BMW M with respect to the previous E46 M3's S54B32. There was no trick airbox and increased duration cams. Instead, they worked the fundamentals: there was no replacement for displacement.
The stroke changes were taken directly from the prototype development of the unreleased V10 M5 CSL and it's 5.5 liter S85B55.
No carbon airbox?
Stroking a V8 is expensive, and the M3 V8 GTS was already a massive premium selling for close to 150,000$ US back in 2010. The GTS had the original M3 V8 standard air intake system manufactured in plastic.
By this era, BMW M had mastered the engineering and design of sealed air intake systems after introducing the design on the V10, there was no performance to be found here unlike the S54.
I assume BMW M was, at some point, restrained by accountants on any plans for a carbon intake purely for noise.
It did have a unique touch, the plenum was color matched to the GTS' Fire Orange U94 code and finished in a frozen finish. Another new factory option introduced with the M3 V8s.
My take, from Germany.
To pay homage to the GTS, I felt the only brand & partner I could turn to was René at CarboProject. I have been running variants of the OE+ S65 Carbon Plenum from René at CarboProject since late 2020.
In 2020, I started with a gloss unit testing a thinner carbon lid, it had the original bolts on the lid and it ended up vibrating. Since then, the bolts were discarded and it's been a flat top for all production units.
I couldn't do without the noise and replaced it with a unit that was returned due to a weave error and a failed seal.
I repaired it with urethane and sent it - I wanted the noise. The urethane seal lasted 2 years until it failed as documented in the previous entry.
The V10 M5 experiments.
René has been consistently improving the product and expanding customization possibilities with the rapid adoption of his unique OE+ design.
We recently explored OE style painted finishes on the S85 OE+ carbon plenums, offering a wrinkled and smooth satin black finish over the carbon lids.
V10 guys can be either over the top, or extremely subtle. This was a true OE+ upgrade - all about the noises with none of the flash.
My M3 V8 specs.
After chatting about this since the Spring, René's production schedule free'ed up and we had time to tackle this new project. I commissioned the first custom color unit in August, it got here on September 1st.
I first filmed and edited a reel of the unboxing and fitted to the engine bay.
UPS managed to get it to Quebec within 4 days - that was fast. The taxes and duties were +/- 250$. There are good news for Canadian M3 V8 owners: we can avoid duties because of the latest CETA agreements. I'll get some money back :)
As always, René over-packages these with styro-foam bubble wrap, double layered boxes and more soft foam sheets.
My first impressions: woah.
This popped way more than I anticipated for a few reasons. I had initially spec'ed Frozen clear coat, but René wouldn't hear it. That's part of dealing with Germans (!).
Sometimes they know best. The Frozen clear will hide the carbon weave.
Inspecting the paint, it was proper. The wet sanding and polishing process was properly done. There were no visible sanding marks, orange peel or pin holes.
If you put your face to it in a way that you will never, ever do. I found a single, small pin hole that can easily be corrected if I wish to.
I don't - this will get a paint protection film applied over, something I never thought I'd consider for an engine bay part.
New premium details.
Instead of a new option on the current listing, this will be a stand alone product on EuroConnex.co. In part due to the obvious aesthetics nuances, and in larger part due to the attention to details that make this a premium product.
Any BMW color codes can be replicated on the plenum. Owners with black, white or silver cars have the ideal base to explore contrasting colors.
Stencil > Sticker.
The standard carbon plenum uses a white M Power sticker applied before the clear coat is sprayed.
It's been a distinguishing visual cue to René's plenum, which various copies from off brands that fail to replicate the placement, sizing and proper font René uses.
The aesthetics are achieved using a stencil to let the carbon work peek through. It is the only option for the custom color carbon plenums.
The font, size and shape of the M Power are retained 1:1 on this new unit.
It's subtle, superb touch that means business. Carbon can easily be overdone for aesthetics.
This sits on the other end of the spectrum: less is more.
René commissioned his painter to refurbish and coat the underside of the plenum with a hydrophobic, oil resistant wrinkled coating. It looks better, and is more durable.
The OE units lose their dark black appearance over time and exposure to oil, turning grey in the process, with easily noticeable stains.
If you had any doubts, there is no trickery nor short cuts here. The lid is still a complete pre-preg and autoclave 2x2 weave carbon.
You can see the carbon sheets as you peak through the air entry.
Engine bay aesthetics.
As good as it looked on the garage's floor, the final say would be once it sits on top the S65. I got the OEM plenum off in 5 minutes and carefully greased, and carefully aligned the painted carbon plenum.
My first impressions: 2x woah - my goodness, yes.
As I installed it, this is when I realized this would need a PPF. Not a single mechanic would pay as much attention as you will when installing it. I suggest putting microfiber cloth to avoid scratching it if you won't have a PPF applied prior to installation.
It is especially risky by the back side of the plenum where it is designed to clear the bolted chassis bars.
The contrasting lid with the black lower section is the only way I feel this can look as good.
The complete carbon plenums without an edge would look really weird here, and the paint lines would need to be perfection.
BMW's solid gloss colors are beautiful, in part for how much lighting influences its hue. The chassis being out under the moon's light looked much darker than the plenum under the LED light.
The clip below was filmed with a shotgun mounted microphone on top of the camera. There's no enhancements during editing.
I do my best to give it to you straight. Say no to the Fugazi, say no to under hood microphones to falsely advertise products.
My sound notes:
- The money zone for this plenum is 3 to 5,000 RPM - it’s rather guttural and lets new frequencies through the cabin.
- The volume is enhanced across the board, velveted in a bassi’er tone than OEM.
- The top end, closing in the increased 8,600 RPM redline starts to shriek just before the upshift.
Up next: you get to spec yours year long right here. Slide in my DMs to chat color codes and ideas.
I may revisit this Series later on and fit a carbon airbox lid to document the sound increase.