The carbon slicktop thread

[JeST]

[JeST]

[Obioban]

Tough crowd.

[Tbonem3]

hahah

[mainstreamer00]

^
Thirsty bro?

Will post actual roof pics when it stops raining.

[pawa_k2001]

Those pictures are like if someone asks for cleavage and gets this..

[mainstreamer00]

;}

[Obioban]

This thread is useless without pics 🙌, but for real, I just like to see E46 with carbon roof conversions...

[Albino09]

This thread is useless without pics 🙌, but for real, I just like to see E46 with carbon roof conversions...

[heinzboehmer]

I've heard/read somewhere the actual carbon fiber roof panel is only about a 12 pound weight savings over the slick top steel roof panel. Can anyone confirm this?

Feff

Lang's roof is supposedly the lightest and their website states it weight 7 lbs which is 3.175 kg. RealOEM lists the factory slicktop panel as weighing 8.564 kg:

https://www.realoem.com/bmw/enUS/part?id=BL93-USA-04-2002-E46-BMW-M3&mg=41&sg=30&diagId=41_1103&q=41318242962

That means the lightest CF roof saves 5.389 kg which is 11.881 lbs. So yup, about 12 lbs saved with a CF roof. Although keep in mind that this is at the highest point on the car, which is significantly more impactful than in other places.

[mainstreamer00]

Sounds about right - all other components are the same in the conversion, so it's a matter of steel vs cf.
The actual roof skin is very thin - can bend/roll it with your hands.

[Feffman]

I've heard/read somewhere the actual carbon fiber roof panel is only about a 12 pound weight savings over the slick top steel roof panel. Can anyone confirm this?

Feff

[BMWahba]

Nice, I’ve had this done and happy to answer any questions if anyone has as well. The weight difference from a sunroof car was very noticeable.

[Epsilon]

I've seen many slicktop write-ups from M3F, but none here yet. Hopefully everyone can contribute.

First, the why:
*CSL build
*Race car?
*You lose ~52 lbs off the top of the car according to Lang's website
*More headroom and helmet space
*Aesthetics
*True slicktops don't readily come to market often

Notable carbon roofs to choose from (some clear coated and some not):
RKP (formally called Challenge) - https://ind-distribution.com/product...bon-roof-panel
Bimmerworld - https://www.bimmerworld.com/BMW-Part...er-Roof_2.html
Lang Racing - https://store.langracing.com/bmw-e90...er-roof-panel/
Karbonius - https://karbonius.net/producto/bmw-m...al-roof-panel/

Slicktop headliner:
https://www.ecstuning.com/b-genuine-...k/51442699065/

Slicktop coathook (L/R):
https://www.ecstuning.com/b-genuine-...et/51168223047
https://www.ecstuning.com/b-genuine-...et/51168223048

Trunk drain plug to fill antennae hole:
https://www.ecstuning.com/b-genuine-...g/51718170298/

Roof bow:
https://www.ecstuning.com/b-genuine-...w/41328242075/

CSL roof insulation:
Front: https://www.ecstuning.com/b-genuine-...t/51488229733/
Rear: https://www.ecstuning.com/b-genuine-...n/51488229734/

CSL roof moldings (can use existing):
Set - https://www.ecstuning.com/b-genuine-...51137897925kt/
Left - https://www.ecstuning.com/b-genuine-...137897925~geb/
Right - https://www.ecstuning.com/b-genuine-...137897926~geb/

Wurth Glue
Wurth bit to remove welds

BMW Adhesive (83190417144):
https://www.ecstuning.com/b-genuine-...l/83190417144/

Pliogrip Glue (Alternative glue):
https://www.amazon.com/Valvoline-Pli...a-571599294458

3M Panel Bonding Adhesive (Alternative glue):
https://www.amazon.com/3M-08115-Pane...6K7B5Q45H68X60

The front windshield may also crack when removed so be prepared for a replacement. I've read some folks call a mobile windshield guy to do this.

FAQs:
Why not use an OEM slicktop steel roof which is half the price?

• From what I recall, the consensus was that it is difficult to weld the thin metal and not warp it. For the cost of the mod, you go all the way.
• Update:
  • 3M Panel Bonding Adhesive can be used on OEM metal roof instead of welding. See Post #17.

What is the advantage if I already have a factory slicktop?

• Not much.

Weights:

• OEM Factory steel: 20 lbs according to Lang's website
• Carbon roof: 5-12 lbs depending on manufacture

Shops that have performed this:
ABS AutoBody in Southern California - $1.5K


Videos:

https://www.youtube.com/watch?v=Bny08_GKhNk

https://www.youtube.com/watch?v=wmC-gooNM0M

https://www.youtube.com/watch?v=kXnRyO38_rQ

https://www.youtube.com/watch?v=6TovbVfvpyY

https://www.youtube.com/watch?v=fspk3LgHIIw

https://www.youtube.com/watch?v=WgRp36WF6qg

https://www.youtube.com/watch?v=wF4-oLDS50Y
https://www.youtube.com/watch?v=0jdThGJtem0&t=1958s

Build threads:
https://e46m3.bimmerpost.com/forums/...d.php?t=877448

Expected costs:
https://nam3forum.com/forums/forum/m...ge6#post108572

Anything else? I will update as more feedback comes in.