Water, seals - and conservation.

Water, seals - and conservation.

"These build journal entries are part of a Special Series covering BMW M's most popular wing designs.

Written in collaboration with Silvano at CarbonProduction GmbH, I take you into the historical development of these wings all the way to my unboxing impressions of the GTS, GT4 and M235/240i Racing wings. 

In this entry, the little things forever matter. I unbox and document the recently developed and improved replica of standard GTS mounts."
- Matt

30 days on, I miss the wing. 

A month ago, I had to remove the Vorsteiner CSL trunk to go back to OEM. This was needed to 3D scan the ducktail for the upcoming, higher quality E92 CSL Carbon Trunk. I also couldn't bear the fitment issues with the trunk anymore as I documented in "I unknowingly went dumpster diving.

I had surprisingly grown to love the GTS wing aesthetics -  I just couldn't deal with the little things that weren't up to par. 

I didn't have the correct mounts.

The Vorsteiner trunk was drilled to fit the GTS carbon wing I source from Germany,  but I didn't use the kit's risers. Silvano only had the GTS pocketed mounts for his GTS and GT4 Mk2 carbon wings.

I had previously documented them and didn't really like the style. 

The pocketed style is a better fit with the GT4 extended risers. 

The 1:1 GTS mounts were meh. 

The mounts were 1:1 replicas of the original GTS design - and for as much as I love sticking to OEM designs, at times, BMW M just didn't do it right. 

They were too wide for the black titanium hardware provided by CarbonProduction on the GTS wing. I wasn't going to run silver hardware here. The mounts were also pretty chunky and heavy. 

We couldn't fit the tapered washers for the bolt.

The picture above leads on to another problem. We had to seal the mounts to the trunk with a custom made urethane seal as the underside are perfectly flat. 

The improved GTS plain mounts. 

I poked Silvano to create an improved set of mounts over the Summer to offer a 3rd option on all wings sourced via EuroConnex. He sent over a few CADs, we signed off on it and off to the German machine shop it went. 

I received a set to review by mid-October and unbolted the 1:1 mounts off my shelved wing to compare. 

I filmed and edited a reel here.




There are a few visual and technical changes versus the original BMW design. 

The obvious first: there are 2x rows for adjustments to the Angle of Attack. This was a functional design decision: only 2x rows are used on the carbon board for adjustments.

The height at which the rows sit against the AoA wing sections is dictated by this bolt hole - and it's fixed. There's no way to make use of a 3rd row. 

Outside of aesthetics and weight reduction, we had no idea why BMW spec'ed 3x. I lost the tapered washers (!) - my bad.

The second obvious difference is the thickness - and thus, the weight! 

There's simply a lot more aluminum machined off the original billet block. 

The lower tapered section is machined even lower to reduce weight and to have a sleeker design. 

Flip the mounts, and there's where the most important functional design improvement is noticed. 

Finally, we have channels for o-rings to seal in the trunk efficiently, and cleanly, without having to create a custom urethane seal. 

I can't wait to have this back on the car next year. 

I find the simple, little things make or break experiences with aftermarket parts, ever more so on a wing that sits out back for everyone to see, and yourself, as it sits in your rear view mirror. 

The new GTS standard mounts are now available year long here, or can be spec'ed optionally on the GTS and GT4 Mk2 wings. 

Leave a comment

Please note, comments must be approved before they are published

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

The latest entries to the Stripper's build journal

m3 v8 programs
I source what I document.