When I worked with Mikhail @ SlonWorkshop to introduce the carbon fiber chassis reinforcement wall back in the Fall of 2020, it was met with black or white reactions.
Some said this was snake oil and I was a money hungry douchebag (hi Brian!), others cut through the grand standing and saw the probable use case.
Is this the next carbon fiber plenum of E9X M3 products?
So why should we do this?
The E46 & E9X chassis are aging: subframes crack, bushings get torn apart, diff bolts break - sh*t happens.
Newer generation M cars continue to strengthen their chassis as they feel ever more comfortable, yet are also ever more capable of sustaining high spring rates, increased dampening and solid subframe bushings.
"We can close the gap and modernize our chassis. "
By introducing a solid, lightweight carbon fiber panel at key structural points of the chassis, rigidity is increased.
The product builds upon key chassis strengthening techniques used by automotive manufacturers such as Audi on the A8 space frames: they incorporated carbon fiber bulkheads to improve chassis rigidity.
BMW M used a similar technique with the introduction of the carbon fiber roof on the E46 M3 CSL. The CSL had chassis rigidity figures of 18,750 nm/deg while the standard M3 had 18,500 nm/deg.
Slon Workshop was inspired by the chassis rigidity figures from the E46. The E46 sedan with folding seats had a 13,000nm/deg rigidity figure, while the E46 sedan without folding seats with a factory metal wall had 18,000nm/deg rigidity figures.
So how does it work?
The chassis wall is made using vacuum infused carbon fiber and is available in 1x1 and 2x2 weave pattern. It comes in raw carbon fiber in a glossy finish
When the E46 variant was published on NAM3, it took less than 48 hours to fill up the Group Buy. These guys know a thing or two about the dangers of an aging platform.
The product is glued with OEM BMW structural adhesives.
Yes - this is fully compatible with the E46 and E9X rear seats. No more folding seat usability, yet you retain the rear seats for an ideal dual duty mod.
For some of us, this pushes back the need for a welded roll cage.
My initial impressions lead me to believe this will be useful. The carbon fiber is purposeful: it’s a sturdy piece without flex. The vacuum infused carbon work is very well executed.
I’ll report back with installation notes.
How can I get one?
This is available factory direct on the Connex - year round under Curated Specials.
It unfortunately takes months to get due to manufacturing time - a few units are in stock.