Re-visitation rights.
"In this Product Series about the widened carbon fenders, I document the logistics, unboxing impressions, test fits along with my recommendations on new wheel & tire fitments.
After numerous trials and errors, I follow it up with the development and final fitment of the V2 variant now available.
In this entry, I discuss the intentions to revising the original V1 design of the widened fenders, and the development process to the improved V2s."
- Matt
When delays become the standard.
The last entry to this Series was in November '23 - it's been 10 months! Updates specific to the fenders were delayed for a myriad of reasons.
The Phoenix's entire paint work was needing a redo for reasons to be discussed and I was awaiting the delivery of the prototype set of CSL style wheels from the Bespoke Forged Wheel Program.
The wheels showed up later in early '24 and the paint redo still isn't finished as of September 2024. Ultimately, this presented the new opportunity to revisit numerous aspects of the build, including the V1 version of widened carbon fenders.
Misaligned specs-to-purpose.
The purpose of the widened carbon fenders is to widen the potential track of our E46 M3s, reduce front end weight and gain aesthetic points in the process.
In all 3x categories, the V1s fell short of perfection. Considering the cost to source, and paint these fenders, they should be perfect.
Fender tabs.
On the original metal fenders, there is a section of folded sheet metal closest to the tire. Its purpose is to to add rigidity to the flimsy metal and creates a tab to position the wheel well liners.
The V1s recreated every single design feature of the Genuine BMW metal fenders, to a fault.
Notice the white line across lower section of the fender? That is the liner tab.
The tab is a section that most often gets rolled by owners looking to maximize fitment. On a carbon unit, cutting is the only option. I hadn't done it prior to paint. It was an oversight on my part.
On a widened carbon fender that's far stiffer than metal and aims at optimizing wheel fitment, this section not only serves no purpose, it's a detriment to it.
Wet carbon layup.
The original manufacturer of the V1 was avoidant of the conversation regarding carbon manufacturing process, using non industry standard terms such as "sandwiched" carbon.
The V1 fenders were made from vacuum infused carbon fiber.
In short, carbon resin is laid into a mold and the epoxy is vacuum injected into the resin. There is no post curing required, leading to cost effective method of making carbon parts.
This process most often leads to air bubbles and weave defects. The additional epoxy also creates a heavier part compared to pre-preg carbon processes. The V1s came in at 1,200 grams per unit. In a vacuum, it's light - but it could have been far lighter.
You will notice epoxy residue that dried off in a glossy appearance, signs of wet carbon layups.
White gel coat finish.
Most important to some E46 M3 owners, the V1 fenders were gel coated in white across the entire exterior shell. This was chosen by the manufacturer to hide weave imperfections and lower manufacturing scrap rate.
While this saves some paint and body labour, it fully eliminates the possibility to run fully exposed carbon fenders. To some, it matters.
The inner sections were also coated, including the inner door section.
Unless you'd bend over and remove the liner, there would be no visual way to tell these were carbon.
An attempt was made.
Products improve through the feedback I receive from customers, and my own. I reached out to the manufacturer to improve the product and met a dead end.
In my now 4 years running EuroConnex and sourcing "wishlist" products for my M cars and likeminded M owners, I have come to the realization that products are one part of a very humane equation.
Values that translate in service quality matters - and some people simply don't care.
With The Phoenix' restoration dragging, I put the V1s up for sale. They were sold to a customer in the US with an E46 M3 race car.
They were primed, packaged, and shipped.
The V2s.
I thus turned around to a German carbon manufacturer that I knew cared about creating the best product, owning an E46 M3 himself; Silvano from CarbonProduction.
He works very differently to the previous manufacturer; using development & manufacturing processes I have come to favour in the creation of new carbon components.
We have notably developed the subframe braces together amongst other niche, functional products and the signature GTS/GT4 wings.
CAD design iteration.
To begin with, we started working from original CAD data of the E46 M3 front end. This is a significant departure from the previous manufacturer, who used an original fender and reshaped the curvature manually.
We tested different design curvatures to the wider arches, retaining fitment with the original bumper.
We settled on a design that extended the top of the arch by 10mm, however, we slightly reduced the rounded bulge of the initial V1s for improved aesthetics.
We eliminated the fender tab from the lower fender liner bolt holes all the way to the front edge of the wheel well. This design choice does not compromise any mounting point of the fender.
Mold machining and creation.
A significant improvement to the manufacturing process of the V2s over the V1s starts with the machining of a master positive mold. Following similar processes to the 1:1 CSL carbon diffuser development, this allows ultimate precision from CAD to physical product.
Moreover, having a positive mold ensures that any defects to negative molds can be redeemed rapidly, or a new negative mold can be created, supporting the long term production of a product.
The positive mold is actually comprised of nearly 10x pieces that come together to form the complete fender.
The first negative mold was created from pre-preg carbon fiber applied directly over the positive mold.
The negative molds were cured in autoclave. The process activates chemical hardeners and solidifies the matrix, reinforcing the carbon fibre.
The end result of the mold manufacturing process is this negative mold that will be used for production units.
Weight testing.
The next step to the development process was testing different carbon layup processes and techniques to achieve our desired weight and rigidity.
The V1s weighted 1,200 grams using vacuum infused carbon - they were needlessly rigid, and thick, making installation more difficult.
Our goal was to make a lighter fender that was also more flexible in key areas, while retaining rigidity for impact resistance. We targeted a 25% reduction in weight for 900 grams total.
On the first tests, we drastically beat our target by coming in at 631 grams.
However, the fender shape was too flexible as captured in this video. For production units, we opted to add a unidirectional carbon insert in the area pictured below to improve rigidity.
The final production weight of the fenders will be +/- 650 grams, a near 50% weight reduction over the V1s. 
Targets were hit and bested: we had a lighter fender, with improved functionality and the possibility of raw carbon finish.
Up next: I import and unbox the fenders, and document a rapid test fit.
The V2 widened carbon fenders are now available here.
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