Carbon monocoque

[David Morton]

I was in the Schnitzer garage during the 1997 Le Mans 24h and the car was the Gordan Murray designed McLAREN F1 gtr using the BMW engine. About 0800hrs JJ Lehto fell asleep. Not really a big deal unless you realise he fell asleep while he was driving. The car spun into the brick wall on the right hand side between the start straight and the pit lane. It had to do another lap to get into the pits but that was the last lap it did. The team stripped all the bodywork and ancilliaries and then Murray examined the front right area of the cf monocoque. To me it looked like a small fracture - I've seen bigger cracks with bandages over them in aeroplanes that I flew -but Murray retired the car as in his, and Charlie Lamm's opinion, this small crack had wrecked the front end of the monocoque. And yes, watching the team pulling it apart it did seem quite brittle. I've got the whole episode on video. I'll try and reformat it - if nothing else it's quite interesting.

 

Miles & Urs,
I've benn thinking on doing a GT40 roof just exactly like you described. Using a core to make the roor would or should cure the problem of the roof sagging down on conposite GT40 roof. I use a flexible foam core material that would work really well. I have plenty of honey comb aluminum and arimide, Hexel's HRH-78 that would be perfect for the job. I have enough carbon cloth to do the roof also.When I get some time, I'll do it.
Right now it a little hard to figure doing anything in carbon around this part of the world. Supply is on and off, mostly off. The big aircraft manufacturers are eating up all the carbon that is being produced. My last 100 foot roll of carbon cloth cost $3300.00 USD. The price can go from $28.00 per yard to $100.00 per yard. Not very stable to go ahead and estimate a product. My polyester resin went from $649.00 per 55 gallom drum last Nov.'07 to an even $800.00 per 55gallon drum last Wed. I/02/08 . I have no idea what epoxy resin is selling for now!
Dave, did they fix that chassis or throw it away?

 

[David Morton]

Well, it came up for sale a couple of years later but I don't really know it it had a replacement monocoque. At the time a few guys in the team said it was scrap and I asked if they could thow it out - in my direction. Not a chance.....
Anything can be repaired/resurrected/fabricated when you look at what goes on in the Cobra world and to some extent in, the GT40 world as well. There are some 'clever bastards' out there.

 

[Miles]

Question already answered by FRPGuy!

 

[Randy V]

Bill,

I think I still have a 130 yard roll of omni-directional CF Mat.. Pretty thin stuff - I was going to use it to build a comp body for one of my GT1 cars. Car's gone. Might also have 20yds or so of Kevlar. Better have a sharp scissors..

 

Randy, I'll pass! I used to use the CF mat when I was building rowing shells. I haven't had a use for it since 1982. I got plenty of Kevlar style #285 twill that I can't find a use for also. I don't dare sell it. If I do sell it, that's when I'll need it. Pretty tough stuff to cut. Try grinding it, it fuzzes up beautifully! Thanks for the offer though. Bill Hough - datonabill - FRPGUY

 

What really has my curiousity up, is what would a properly designed GT40 mono carbon fiber chassis look like?

 

[Russ Noble]

What really has my curiousity up, is what would a properly designed GT40 mono carbon fiber chassis look like?

Bloody nice I would think Bill.

At that stage you would go for a complete suspension redesign push/pull, bellcranks, stressed motor/trans etc and drag the whole lot into the 21st century. All in a timeless body shape. Add some unobtrusive chin spoilers and rear diffusers and wow......

Who's going to be first. Jac Mac? That'd be a good project for you!

 

[Jac Mac]

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[Ian K]

If anyone could make a double skined epoxy carbon roof with a honeycomb core then I can see real benefits, (pressumably one could then do away with a roll cage?). In practice this could only be too expensive. One could quite economically use a foam core though...

Just some idle thoughts on the subject!

ERA's roof (maybe entire spider) is high temp/low shrink resin reinforced with CF/Kevlar
composite. Better stiffness and holds shape better, but not enough of a significant structural
improvement to do away with a cage.

GT Chassis illustration

Ian

 

[fostereast]

Koenigsegg Official Website

Link to mid-engined supercar w/Carbon Fiber monocoque

 

[Nicholas Gomez]

What happens if you get into a smash-up? The entire monocoque is ruined right? Very costly.

 

[Russ Noble]

If you're building a carbon mono you're not pitching it to the lowest common denominator, you are going for the top end of the market. Cost is irrelevant and that's what insurance is for anyway!

 

[Urs]

Hello nicholas
you could n t say that in every crash you could throw away the mono.You have also repair problems with a steel momo a alu mono or a tube frame.

Russ
When i see what costs for a sequential hewland gearbox is or a ZF then i think also a chassis could cost something.

The suspension is also a challenge there are a lot suspension kinds on different cars.
i started now with the templates of the front part.Somebody knows the weight of the original steel chassis?

greetings from swiss

 

[Russ Noble]

Merlin,

385lbs or thereabouts according to Fran on this thread http://www.gt40s.com/forum/gt40-tec...ls/22530-chassis-weight.html?highlight=weighs

Are you going to build a CF car?

 

[Urs]

we try

 

[Joe]

thats really exciting news!
good luck

Joe

 

[René]

seen this?
looks lovely...its for some new (hybride) Ferrari, it looks a bit ala GT40 (roof), but I guess it will get butterfly doors?

love the looks of that part.

 

[Mike Pass]

Mick Sollis at Southern GT does a front and rear clip in carbon fibre. Glenn Mason has them on his car.I had a good look at the rear clip when I was down there some time ago. Not only was a huge amout lighter than GRP but was very, very rigid as well. I believe that the rear clip is less than £4,000 but I'm sure Mick will give you a price and weights etc. I understand that Tornado offer a carbon chassis but I haven't seen one yet.
On the repairability front my GTD space frame had had some front end damage in a previous existence. It took one afternoon to jig it up, weld in new metal and paint it. Try that with CF.
Cheers
Mike

 

[René]

that from Tornado is this thread I guess>>

http://www.gt40s.com/forum/vendor-manufacturer-announcements/31606-carbon-mono.html

en in this thread they build a complete carbon GT40...lovely.

http://www.gt40s.com/forum/gt40-build-logs/24086-carbon-gt-mono-10.html