My carbon fiber hood saga...

[bigjae46]

Finally. I have a CF hood on my car...



Definitely not a Cars and Coffee cosmetic grade part but it looks perfect from 50' away at 50mph.

It has been an expensive endeavor. Although my purpose is usually to reduce costs that was not the goal. The goal is to create the lightest hood possible.

A carbon part is only as good as the mold which is only as good as the plug. So we start off with a $1300 OEM hood.

First attempt failed. Had a leak in the mold somewhere. It tossed the part and the mold. It was also 18lbs! Way too heavy



So the second attempt. Long story short...I re-designed the mold and made it worse. It was extremely difficult to get the part out. I damaged the OEM hood and the CF part getting it out of the mold.

But I did get a usable and dimensionally accurate part...



The underside has a 1x1 spread tow which is the same stuff that F1 teams use. So I guess my car is an F1 car now! lol



It weighed 4.6 lbs but it was way too flimsy. I laminated some reinforcement on the underside. The core is massive overkill here, definitely an opportunity to optimize going forward. I need to do some experiements.



Vents and stuff trimmed and the hood is ready for clear coat. Weight here is 5.6lbs



Cleared and installed. Don't worry...I won't quit my day job to be a painter. Never mind the runs and inconsistent finish. Came out to 8.2 lbs which I'm kinda happy about. Its 15lbs less than the VRS/Seibon hood I had. The vents are probably almost 2 lbs. I can get close to 7 lbs with...CF hood vents! haha



I'm not a stickler on cosmetics for this car but I do want something that is more presentable. I'll use this to test and identify any issues. Hopefully in late spring/summer I'll be working on CF Hood V3 which will hopefully be the last version!

I have to admit, I absolutely underestimated how difficult this would be. An E9X or F8X hood would be MUCH easier without the kidney grills. So when you see a $2k price tag for a finished CF hood...that's a good deal!

[oceansize]

The only way forward is a bunch of mistakes, I love it.

[ugaexploder]

That is sick that you took on this endeavor...I'm sure you learned a great bit and could probably tackle some smaller pieces with relative ease in the future. Look forward to your projects man.

[Slideways]

Looking pretty good for a CF part that was made at home.

Are there any second hand autoclaves out there? You might need an upgrade from that space heater lol

[9kracing]

but it looks perfect from 50' away at 50mph.

lol'd pretty hard at this

Nice job man.

Did you run hood pins with the Seibon unit?

[D-O]

Very impressive for a lone gentleman in his garage. Please keep sharing.

D-O

[heinzboehmer]

That's awesome. Looking forward to more seeing more parts in the future!

[EthanolTurbo]

When is the group buy?

[bigjae46]

Looking pretty good for a CF part that was made at home.

Are there any second hand autoclaves out there? You might need an upgrade from that space heater lol

I can't win...now its too cold in TX! Really not much of an advantage to an autoclave for things like this. An autoclave has better compaction of the layers and heat control for high temp cures. A hood that is cured in an autoclave would be maybe a couple of oz lighter...

I now have an electric blanket to speed up the epoxy curing.

[bigjae46]

Thanks! If anyone wants one and has low expectations...I'm your man! Remember - 50' away at 50mph!

lol'd pretty hard at this

Nice job man.

Did you run hood pins with the Seibon unit?

Lol...Yes I did. That Seibon hood was about 40lbs until I sliced it up.

[WestBankM4]

bigjae46 Probably close to 15 years ago I too laid up my own carbon fiber hood for a 240SX I owned at the time. I used the OEM hood as a mold for the top but when completed it was super flimsy so I made a second mold of the under side also in carbon fiber. I then joined both together and structurally it was sound enough with the hood pins. I mean it still flopped in the middle of the hood at certain speeds but I was happy with it.

Have you thought of copying the underside and just using fiberglass for structural rigidity, you already have the OEM part on hand?

[Cronenberged]

Be worth the drive just to help and learn how you did it. Looks clean to me, any decent body shop could clear it for $300 if you were looking for perfection.

[bigjae46]

Have you thought of copying the underside and just using fiberglass for structural rigidity, you already have the OEM part on hand?

Thought about it and still possibly might go that route. I only used core material around the hood pins in the infusion. The question is what would be lighter? An underside structore? Or more core material?

I'm going to try using more core material for the next one. I need to test this one out and see where the weak points are. On this hood, I used an absurdly thick foam core. I like the idea of a foam core, I think I can go with something about 1/3 to 1/2 the thickness. I could cover 2x to 3x the area while keeping the weight about the same. Then use an infusible core around the curvy and vent areas - infusible cores consume more resin than a foam core.

My current hood was 5.6lbs with the vents cutout.I think I can keep the hood to around 8 lbs and have adequate stiffness so the hood doesn't flex.

[9kracing]

I can't believe nobody makes a quality hood for our cars.

Well, I guess Karbonius does, but I'm not a fan of all the vents.

I heard SLON makes one too, but they won't ship to USA.

Weird that nobody has made a lightweight OEM version in carbon

[bigjae46]

I can't believe nobody makes a quality hood for our cars.

Well, I guess Karbonius does, but I'm not a fan of all the vents.

I heard SLON makes one too, but they won't ship to USA.

Weird that nobody has made a lightweight OEM version in carbon

AJ Hartman does but I think you'll have to reach out to get one made. But I think his doesn't have a complete underside so you have to use hood pins.

The E46 hood is quite difficult because it's a 3 dimensional part. The area around the grills is what makes it tricky. Also getting the flange along the sides is difficult without doing a full 2 sided part. That's where I screwed up, the mold can't be over a 180 degree plane since it's impossible to get the part out without damaging the hood.

So if you're doing a full 2 sided part, the hood will be heavier and cost more to make. Then most who will want a full 2 sided hood will want the part for cosmetic purposes. So this also increases the cost due to the finishing work. And most cars and coffee types are also the tight wads who expect to pay less than $1000 for a quality hood. Then most will want fancy vents and stuff on the car to make it look ricey...I meant race-y

To sell a full 2-sided hood with a perfect finish...I couldn't see it being any less than $2k. Then there's the whole pain with shipping and damage.

An E9X M3 hood has the same issue with the side flanges but there is no front overhang so it will be much easier to make.