Immaculate low mileage 2004 Silver Grey CSL Inspired Build

[Avedis]

My shipment from Karbonius came about a month earlier than expected. I had some free time this weekend which gave me an opportunity to install the Karbonius strut brace.




The strut brace is a replica of the BMW Performance part, so going into it, I knew that I would have to make some changes in the engine bay. What I hadn’t anticipated was just how much improvement could be made to BMW’s installation instructions, and some damages left by a previous owner. Let’s just say the whole project took far longer than the 1 hour estimate in BMW’s official installation instructions. Standby for the world's longest strut brace install.

First the factory strut brace was removed. I immediately noticed the passenger’s side base was cracked. I initially chalked it up to being a cast part, but then I started to consider a possible collision that wasn’t disclosed to me. I checked diligently around the base and edges of the strut tower and there was absolutely no signs of a collision or repair.





However, on the top of the strut tower I found some distortion next to the front hole. I measured out the distance between the damage and the opening. Based on the distance and shape of the damage, it was immediately apparent that someone, at some point, had installed the strut mount in a rotated position. This caused the alignment pin to protrude up and into the underside of the strut tower. It was left that way long enough for it to do some minor distortion to the strut tower and crack the strut brace mount. As you could imagine, finding damage, even minor, on a car in this condition was really frustrating. Even more frustrating was how basic and preventable this error was.



I mocked up the new Karbonius strut brace and it was obvious that if I didn’t level the distortion, the base wouldn't fit right and I would risk damage. I decided to move along with the project and take care of the strut tower at the very end. First, the battery terminal and hood sensor were removed so that they could be modified.


BMW provides diagrams which show the areas of the mounts that need to be removed.


First was the rough cut, then the edges were cleaned up with sandpaper and a file.





I checked my work on the car and realized that the cuts that BMW recommended were not only too complex, but left a ton of unnecessary material on. I went back and simplified things by making a few additional cuts. I also bored out a tunnel so that the battery terminal wires fit better. I’m not sure why BMW chose to cut the mounts that way.



Next the wiring for the hood sensor / anti theft system needed to be cut and extended. Wires were cut, new wires were soldered on, heat shrink applied, then wrapped with electrical tape. BMW’s instructions state to run the wires through a hole/grommet near the strut tower. The Karbonius kit did not include the grommet and I thought of a better and near invisible way that I could route the wires. I chose to extend the wires longer than recommended, then route them underneath the rubber seal and to the sensor.




After yet another test fit, I found that the diameter of the strut mount alignment pin was slightly too big to fit through the base of the Karbonius strut brace. The alignment pin was removed, put into the cordless drill, then sanded down to fit.


Just to be safe and not risk additional damage, I jacked up the car and dropped the strut down. I checked on the topside of the strut mount just to make sure that there wasn't anything still there. Once I confirmed it was clear, I used a combination of 2x4 and hammer to massage the metal back flush. I suppose a "massage" is a nice way to put it. The fix itself was actually a pretty quick and painless process. After a little bit of touch up paint, it was looking pretty good.


You'd think that at this point, i'd surely be done. Unfortunately not. I am working on a solution for better mounting hardware and caps for a more OE look. A few orders need to be placed, so for now I will leave on the hardware from Karbonius. If you made it this far, here are the semi-finished photos, and a teaser of what's to come next.

[liam821]

Wow! Beautiful work, your attention to detail is incredible. Picking the matte carbon for all the door cards and interior bits was next level, and came out amazing. Side note, I wish my garage was THAT clean.

[Avedis]

Avedis Love the build, following as I'm in CA as well (Bay Area) and wondering what your solution is for passing smog with the carbon airbox. I have an 06 SG/Black ZCP as well and putting together the "list" for the OEM+/CSL build.

Thank you! I have been in the BMW world for about 20 years now and I have never really had any real hurdles with smog. There are so many options, none of which I have ever tried, as that would be unlawful...

Few that I am aware of:

• Montana LLC registration, register the car once for the rest of its life for around $150, pay to maintain your LLC.
• Register the car in CA, but in a rural county with no smog requirements (you can Google the counties, recently found out about this from a forum member)
• High friends in low places, for example a person at the smog shop, a contact at the actual DMV itself
• Revert back to stock for smog, then reinstall CSL components.

If you want to use my build sheet as a starting point, i'd be happy to share my Google sheet with you. It is essentially an excel sheet with the part name, part numbers, cost, links, etc.

Amazing work on the seats! These really look the best on this platform imo.

Thanks! They legitimately look like they were made for this car. Following your build as well, great work.

This picture really shows how perfect your interior is, especially for the driver. And to top it off, the steering wheel trim is simple but so proper. It reminds me of the steering wheels on the 997gt3 but yours is even better.

Appreciate the comments. This is really what I was going for all along. Streamlined, driver focused, no distractions. Really happy with how the interior turned out.

[nyc951]

This picture really shows how perfect your interior is, especially for the driver. And to top it off, the steering wheel trim is simple but so proper. It reminds me of the steering wheels on the 997gt3 but yours is even better.

[bavarian3]

Amazing work on the seats! These really look the best on this platform imo.

[eXpensiveGears]

Avedis Love the build, following as I'm in CA as well (Bay Area) and wondering what your solution is for passing smog with the carbon airbox. I have an 06 SG/Black ZCP as well and putting together the "list" for the OEM+/CSL build.

[0-60motorsports]

Wow that looks beautiful!

[Bry5on]

Glad it all worked out and thanks for taking all those nice pictures!

[Avedis]

Seats arrived from AMX in Poland. The AMX purchasing experience was very mixed. It wasn’t a horrible experience, but for the premium price, it wasn’t good enough to do business with them in the future. I don’t want to go into details and turn this into a negative post, as this build thread, and the project itself are really positive outlets for me. We’ll leave it at that and move on.

Factory seat coming out.


Seat rail and electric motor disconnected from factory seats.


Bry5on custom seat mounts mocked up. These things are incredibly well thought out.


I got about this far before I realized I needed to stop and shift my order of operations. Everything came back apart so that I could make a few adjustments then rebuild in the correct order.


First, the seat harness mounting bracket was removed, placed in my vise, and given two subtle bends. The minor adjustment ensures there is no rubbing when the seat moves back and forth.


Next, the Recaro seat bracket was attached to Bryson's seat mounts. All the bolts received Loctite to ensure they don’t back out in the future. The factory seat rail has a threaded stud that passes through the seat mount. The stud is a strange shape with a stepped and shouldered shaft. This required a custom thickness washer combined with the original nut.



After that, the seat cushion could be reattached to the Recaro seat bracket. Bottom half complete.



Next part of the install was the wiring. Again, I received some help from Bryson (I swear, I’m surprised he hasn’t started billing me). First I pulled the seat memory trim off the original seat.



Then out came the wiring harness.


There were a lot of wires, but I only needed four specific ones to wire a momentary forward and backwards switch. Off came the 20 year old Tesa tape which made a sticky mess. Old adhesive was cleaned off of the harness, then the wires were de-pinned and removed.




Old connectors were cut off, motor wires got a jumper cable for the momentary switch. Then I crimped on some spade connectors and finished with heat shrink for extra insulation.


Test fit the wires onto the seat and momentary switch.




Here is the completed look. A lot of work for a little switch, but I’m incredibly happy with how clean it looks.


Final test fit was done in the car to ensure the switch worked. Once I confirmed that, the seat came out one last time so that I could wrap the new harness in Tesa tape and install the upper portion of the seat.



The upper portion of the seat was attached. It was starting to look like a finished product, so I stopped to take a few photos.




New bolts, new nuts, and new covers for a finished OE look.


The fully assembled seats were weighed (50.4 lbs) then installed in the car. For reference the factory passenger seat weighed 63.2 lbs The seats look like they could have been a factory option for a "CS" model if BMW ever made a proper CS for this generation. Really happy with how this project turned out.

[Avedis]

While browsing through member's build threads, I saw a quality OEM+ (thicker) steering wheel posted in SQ13 thread. I reached out to him and he provided me additional information on the seller and the wheel itself.

I currently have a F30 335i and G07 X7 as my daily drivers. Both of those cars have thicker steering wheels. I don't drive my M3 very often, but when I do, the thinner diameter of the steering wheel stands out to me. Part of me feels like it's nostalgic, adding to the overall driving experience. The other part of me feels that it's too thin, detracting from the driving experience. I wanted to try out a thicker wheel to see how I would like it in the M3. Rather than wrap my current wheel, I chose to replace it. This way if I ever wanted to go back to stock, I'd simply swap the steering wheel back.

The steering wheel was purchased from GS Specialties who sells both on eBay and Instagram (LINK). The seller takes an original used steering wheel, strips off the leather, adds new thicker padding, and wraps the wheel in a smooth Nappa like leather. The wheel is ~1cm thicker in diameter but otherwise identical design wise. The 1cm difference in diameter doesn't sound like much on paper, but it makes a huge difference in feel. The seams and stitching are perfect, and the overall craftsmanship is excellent for a very reasonable cost. It shipped from Poland and arrived in a week without issue. I would highly recommend the seller if anyone is looking for custom steering wheel work.






I also picked up this extra long valve stem tool after seeing it recommended by sleeks. The tool fits perfectly into the hole in the back of the steering wheel and cradles the airbag retention spring. This makes depressing the spring a little easier than using a flathead which tends to slip as you apply pressure.




Onto the installation itself. First the battery was disconnected, then airbag and trim were removed.


Wheel removed.


Prior to installing the new wheel I took some comparison photos to show the difference in both diameter and leather.



Wiring was transferred over to the new wheel then it was torqued to spec.


Here is a before and after. Visually, it’s a very subtle difference, but feel wise, it’s a massive change. My plan is to keep an open mind as I drive the car for a few months, then revisit at a later date to see which wheel I like more.



Prior to reconnecting the battery, I installed a quick disconnect adapter for my NOCO Genius 10 battery charger.

[karter16]

so I asked Marek at AMX if he could create a small woven label (clothing tag) with the ///M logo and stitch it into the bolster seam.

Very cool - love this little detail! looking forward to seeing photos of the finished seats!

[1bluemcm]

Cool project. That's some dedication to the parts search. Love the silver greys. Nice!

[Avedis]

I have been in a "gearing up" mode for the past few months and have been slowly ordering major components, small parts, doing research, and prepping for future installs.

As I mentioned prior, the seats and custom seat-mounts are the last components for the interior phase of this project. I bounced back and forth between fixed buckets and more street/passenger friendly seats. After seeing BBB's seats, I decided to order a near identical set.

The specs are Recaro Sportster CS, custom leather upholstery, ///M logo embossed in the headrest. I also wanted to somehow tie in the tri-color, as I did with the seatbelts. Some of the examples of tri-colors integration on the AMX website were a little loud for my taste. I wanted something more subtle, so I asked Marek at AMX if he could create a small woven label (clothing tag) with the ///M logo and stitch it into the bolster seam. BBB provided me with some photos of his seats, and I used the photos to do a small mockup for AMX. Marek quickly took my mockup and designed the woven tag.

Although this is a mockup only, I expect them to look exactly like this.



With the interior nearly complete, I have been able to shift more time and money to other areas of the build. I've probably looked at the CSL intake 100 times on the Karbonius website. Today, I finally ordered the full carbon CSL intake, carbon CSL snorkel, and carbon M-Performance style strut brace from Karbonius.

I again chose to deviate from the original CSL design, ordering all the parts in 1x1 matte finish carbon. Just as I did with the interior components, I will ceramic coat them which will give a satin sheen to the parts. Really excited for the install. In my opinion, a CSL intake is the biggest enhancement to the driving experience and character of our cars.





Prior to ordering the intake, I had already ordered and received all of the necessary parts, accessories, and tools for the installation.



In addition to preparing for the intake, I also ordered a ton of parts for the CSL trunk I posted on page 5


I’m big on doing as much research as possible prior to doing any installation. Just as with the CSL interior parts, I found the lack of comprehensive tutorials for the genuine CSL trunk lid surprising. Because the DIY I did for the CSL interior components was received so well, I will be creating a comprehensive DIY for the CSL trunk lid as well.

[Avedis]

Love the details on the battery. Do you need to keep the charger on it most of the time?

Per Braille and discussion with forum members, it does not need to be kept on a charger all the time.

slavik1988 informed me he left his car in the garage, undriven and uncharged for 3 months. He stated it fired up with no issue. This was one of the main reasons I went with the i48cx over other batteries.

[bavarian3]

Love the details on the battery. Do you need to keep the charger on it most of the time?

Also love the dedication on the seat bracket covers. I had the same dilemma and opted for pick n pull and some careful application of trim paint 😁