I took it upon myself to make a carbon roof panel for the E36 chassis.
Since this was going to be for a race car application, I started off by welding the factory sunroof panel into the roof skin on a bare e36 tub that I had. After the sunroof panel was tacked in next was the body work to make sure the roof panel was flat and that all imperfection had been addressed. When the body work was completed the roof panel needed to be prep/cleaned before starting on the mold.
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Making the mold. After looking at the roof I decided to make a two piece mold. If the mold was one piece the part would lock to the roof. The issues would be with the 90 plus degree turns when the panel drops into the front and rear glass area. I used a tooling glue coat and fiberglass for the mold. After both sides of the mold were completed I add some wood ribs to the back side of the molds for structure. This keeps the mold from warping over time.
Before using the mold I looked over it to address any issues with imperfection in the mold surface. I finished the mold off by wet sanding and polishing the surface so the part can be sealed.
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I laid the mold up with 2x2 twill aerospace grade carbon. After the carbon was laid in the mold I prepped the part to be vacuumed infused with the resin.
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The part turned out great for the first panel out of the mold. After trimming the part the new carbon panel dropped right into its location.
Removed the factory roof panel. Prepped/ cleaned the areas by removing the paint off the sheet metal so the carbon panel will have a good clean surface for bonding.
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Here’s the final part installed on the race car. The next one I do I’m going to add a 1/8” form core in between the layers carbon to add more strength to the panel.
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Awesome work!
How much would someone theoretically charge for something such as that?
what did the sheet metal roof weigh?
BMW e36 M3 #11 ST-3
Subscribed for more information about a fantastic project! (weight savings and whatnot)
Isn't the e36 roof skin a stressed part of the unibody? If so, is the carbon roof designed to act in its place or will the cage [hopefully] take care of that?
I just do it for fun now. When I was building parts it was time and material for one off custom parts.
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I was never able to get an exact weight after removing the skin. For the square footage of sheet metal (.048 sheet metal)that was removed it's about 2lbs a sq foot. The weight of the roof skin without the sunroof plug would be around 17-19lbs. The carbon panel after trim was 7-8lbs.
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all that was removed was the roof skin not the structure that's underneath the skin. On the E36 there's a structure skeleton underneath the roof skin at the front and rear of the roof. The carbon panel that is in place now is stronger and lighter than the steel.
Last edited by mcetuning; 01-09-2016 at 02:09 PM.
Interested in making another one since you have the mold now?
Did you wet lay up or pre-preg? How many layers? Did you cure it in an autoclave? Really cool. I'm impressed by the final quality, came out nice.
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Looks great, regardless of method
sullypants1 Did you wet lay up or pre-preg? How many layers? Did you cure it in an autoclave? Really cool. I'm impressed by the final quality, came out nice.
I used the infusion process to draw the epoxy in. I used standard Aerospace grade 2 x 2 carbon. This was the first part out of the mold I was expecting some dry spots but it turned out actually very well. This one had 6 layers of carbon, If I do one again I'm going to add a 1/8inch Foam core it will add about a pound to the part and the strength of the part will go up like crazy.
Last edited by mcetuning; 02-02-2016 at 06:06 PM.
1. since none of the cabin structure was removed other than the skin, would you feel comfortable installing this on a road-going car with no cage?
2. can you shoot some kind of ballpark price on what you'd want for one of these? no one makes one that i'm aware of. you have the market cornered if you want it.
always trying to make it lighter and faster
^^former build: http://www.bimmerforums.com/forum/sh...-neglected-M3/
current build: http://forums.pelicanparts.com/porsc...car-build.html
instant grams: doktor_b
How did you remove the oem roof, cut it? or drilled into the welds?
looking good. do you have any photos of the OEM factory removal? close up photos of the oem roof removal...
My guess is they'd be more expensive than most would want to pay. I went thru a brief time thinking of making well engineered carbon fiber wings but once you figure in cost of materials, consumables, and what your time is worth the price point gets you to a very limited market of people who are willing to pay for quality engineered parts.
always trying to make it lighter and faster
^^former build: http://www.bimmerforums.com/forum/sh...-neglected-M3/
current build: http://forums.pelicanparts.com/porsc...car-build.html
instant grams: doktor_b
Damn I'll buy the mold. Those wouldn't be much harder then a hood.
Bump
Ok, now that you're back. . . .
Hello there!
It’s been a while but loved what you’ve accomplished with your Carbon roof!
have you ever made any carbon roof molds for the e36 Coupe? I’m currently in the market for one and really don’t want to place an order for one over seas. Rather pay someone in the states.
https://www.facebook.com/john.kamler.3?ref=br_rs
This is who I had make my roof. I know he has molds for both e36 coup and sedan.
John has been doing carbon fiber work for a very long time now.
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