Carbon GT mono

[keohep]

Ok no probs Epoxy is much better very little shrinkage ,iv in the past used vynlester resin it shrinks like nothing else i think as much as 3%.so we had to layup both sides of the foam at the same time with the same layup ,to do simular jobs. i wish I had a Cad and and a plotter,makes life so much easyer.Can i ask what the price of Carbon is in the the usa or europe if any one knows here its around $45 per/mtr

[Urs]

Hello together
The price for a 200 gr Leinen is around 50sfr.
now im ready to cast the lower 2 A- arms for the negativs.
i waxed and polished it 4 or 5 times after this i bring on a seperating coat and then the ( Formenharz) i dont know in english!!
At the end i fill the form up with laminating ceramics .
Then i hope to get it out!!!

[EGLITOM]

Originally Posted by Merlin2222

( Formenharz) i dont know in english!!

resin

tom

[Troy]

Your build is moving along very well - great to see! Keep us posted on your progress. Excellent stuff.

Keron, let me know if you still want a CAD program.

Troy.

[Urs]

now i preparing the molds from the lower A arms to laminate them at the weekend.The molds are made of laminating ceramics (good for tempering)and the black thing you see on the molds is mold resin ,it s very scratch resistant ,to get off more than one thing i hope.
you also see bronce bearings. we lay them in when we laminate the A-arm.and we secure them with a bolt that they are in line.
now i start with waxing and polishing 4 or 5 times and then the disconnect coat.

[Jim Rosenthal]

Urs, I think this project is a great idea and looks terrific. However, you will have enough wooden parts left over to build a WOOD GT40 tub when you are done! Can I have first rights on the wooden GT40?

Seriously, do you have a design weight for the monocoque? My guess would be about 150-200kg finished. Am I close? I have seen carbon-Kevlar body sections like the ones for my GT40 (which are polyester and E or S glass)- they weigh about half as much or less. I think an empty steel GT40 tub weighs about 700-800 lbs. What do you expect the finished car to weigh?

[Urs]

Originally Posted by jimbo

Urs, I think this project is a great idea and looks terrific. However, you will have enough wooden parts left over to build a WOOD GT40 tub when you are done! Can I have first rights on the wooden GT40?

Seriously, do you have a design weight for the monocoque? My guess would be about 150-200kg finished. Am I close? I have seen carbon-Kevlar body sections like the ones for my GT40 (which are polyester and E or S glass)- they weigh about half as much or less. I think an empty steel GT40 tub weighs about 700-800 lbs. What do you expect the finished car to weigh?

Hello
Why not build the mono in wood ; ) i learned carpenter ,and the idea is not too far

until now ,the chassis weighs 45kg including with the integrated rollbar.at the end ,the chassis should weigh around 65 or 70 kg ,but we will see.The finished car should be around 750 or 800 kg.
Greetings from switzerland

[Al Jones]

Urs,is the 427 engine completely alloy or does it have an iron block? A complete aluminum motor would result in an extremely light car. A.J.

[Urs]

Originally Posted by A.J.

Urs,is the 427 engine completely alloy or does it have an iron block? A complete aluminum motor would result in an extremely light car. A.J.

Yes its the alloy block.We try to use only light materials,when it s possible.

[Urs]

Yesterday at 10 o clock in the morning, we started with laminating both A-arms.at 3 hour later we started to tempering both parts in our oven.
in the evening we took the first one out of the molds.Now some pictures from them.
like christmas for me!!!

[Jim Rosenthal]

This car is going to be scary fast. SCARY fast. And I like fast, but this is going to be something else again, like heat-seeking-missile fast....

The Kirkham Motorsports folks have an all-alloy 427 block, machined out of two solid chunks of 356 aluminum, which weighs 75 lbs. (before you put anything in it) They make these on one of their CNC machines. There are some photos of it on their web site. With aluminum heads, forged aluminum rods and pistons, etc, the only iron or steel parts of any size in the whole engine could be the crankshaft and the camshaft. How light would a big-block "Ford" motor be, built like that? 450lbs?

With a vehicle that light, and that much power, how do you keep the rear tires glued to the road well enough to make it go fast? I guess you use very sticky tires.

[Jim Rosenthal]

Urs, 800 kg is about 1800 pounds. Race-ready GT40s with small-block (iron block) engines weighed 2100 or so pounds, I think. I suspect your car is going to be a lot lighter than 1800 pounds. More like 1200-1400. If you use CF for bodywork also (and why wouldn't you?) the two heaviest things in the car will be the crankshaft and the glass windscreen. Your power to weight ratio is going to be better than a McLaren's, and those are VERY fast cars. Think of a Beck Spyder with a 427 engine....

[J. Salmon]

I thought GT40's were more like 2800 pounds in race trim? 800 kg is scary light.

In the supercar world (road cars), there are two groups: metal, and carbon. The list of cars in the carbon section is pretty small. A few Ferraris (F40, F50, Enzo), Carrera GT, Pagani, McLaren, that Gumpert thingy... I can't be missing too many. It's like an order of magnitude beyond to be in that group. This is simply one of the most amazing things I have ever seen.

[Jim Rosenthal]

You may be right. I don't think they were 2800 lbs, but I got my information more or less from the Horsman book, and a lot of his info about GT40s is about the Wyer team cars which all had small-block engines and ZF transaxles, which are lighter than T44s and 427s. Maybe 2300lbs; they had early CF body parts and some aluminum as well. The GT40 was heavy for a race car, I do know that. The Mirages that the Gulf teams fielded soon after were much lighter cars.

Urs' car is going to be very light indeed. So light that you think about ways to cut weight out of components that you don't usually think of as heavy- the glass windscreen, for one. It sort of sets you off on a chase to take weight out of everything. It will be interesting to see what kind of spring rates he picks, etc, because when you make the car so much lighter all those loads are different and I would assume less. Lighter springs, lighter shocks, different sway bars- the list goes on and on. And the fuel tanks become a proportionately bigger part of the car and affect trim more as the fuel gets burned and the weight distribution changes....it's all very interesting.

I love the carbon fiber control arms. I wonder what one of those would cost....

[Urs]

Originally Posted by jimbo

You may be right. I don't think they were 2800 lbs, but I got my information more or less from the Horsman book, and a lot of his info about GT40s is about the Wyer team cars which all had small-block engines and ZF transaxles, which are lighter than T44s and 427s. Maybe 2300lbs; they had early CF body parts and some aluminum as well. The GT40 was heavy for a race car, I do know that. The Mirages that the Gulf teams fielded soon after were much lighter cars.

Urs' car is going to be very light indeed. So light that you think about ways to cut weight out of components that you don't usually think of as heavy- the glass windscreen, for one. It sort of sets you off on a chase to take weight out of everything. It will be interesting to see what kind of spring rates he picks, etc, because when you make the car so much lighter all those loads are different and I would assume less. Lighter springs, lighter shocks, different sway bars- the list goes on and on. And the fuel tanks become a proportionately bigger part of the car and affect trim more as the fuel gets burned and the weight distribution changes....it's all very interesting.

I love the carbon fiber control arms. I wonder what one of those would cost....

Hello Jimbo
You only have to change your suspension points then we can talk about the price of lower an upper A-arms The molds ar ready!!
And you are right . There are a lot of challenges on our way! But that s the intresting thing.
next week i will take off the molds for the upper arm.
thank you for all the posts.

some swiss greetings.

[Del]

Urs - could you give some more detail on the layup of those arms? Look amazing!

[Jim Rosenthal]

Like the man said, there are metal-chassis cars, and then there are CF-chassis cars, which are in a different league altogether. Nothing is as light as those; with 500hp and 1200-1500 lbs total weight, it really IS going to be like a Beck Spyder. Except more so. My Beck Spyder had 180 hp and weighed about 1300 lbs. And it was very quick- until it started to get light in the front end. You're going to need some downforce, I think.

Greetings from Maryland. If you plan to be in this area, ever, let me know and I will show you 1149, which with some luck might be done and driveable.

[Urs]

Originally Posted by Delinquent

Urs - could you give some more detail on the layup of those arms? Look amazing!

Hello Del
at first there are two layers of leinen ,then we put in a cord of carbon rowings 185cm around the bearings in one peace.
then we put in some short cords for ears and strengthening .And at the end we close the part with the leinen again at the under side.Difficult to subscribe everything.
you can pull around 120 tons on one bearing.


@Jimbo
thank you for inviting.
You are also invited to visit me in switzerland .

[Del]

Thanks for that Urs - very interesting. I've done a fair bit of simple layup, mostly GF but carbon as well but never tackled anything structural, I don't think I'd have confidence in anything if I made it!

I'm looking to learn more for my own CF project car so watching your build is truly inspirational. Maybe when you do one of the arms you could do a series of photo's showing the layup as it happens?

[Urs]

Hello
some good news we got some nice wheels with Rolex 24 experience.!!
Now the build up goes to the rear section. With engine, transaxle and suspension.