MK IV tubular spaceframe drawing

I have now constructed an alternative variant of the side boxes.
Aluminum plates riveted to the tanks.
Weight saving approx. 16
These two tanks are bigger than we thought.
To make them removable I changed the side boxes again
Thanks to the McLaren group, Udo and Andrew for the great input
Hi ,
I have now completely redesigned my frame. Additionally I have done extensive FEM studies. I have always used 42crmo4 with 800-1000Nm tensile strength as material.
The tubes are 40x40x2 and 25x25x2 mm
Unfortunately I have to realize that there are only round tubes made of this material :(
Now I have only two possibilities to redesign everything with round tubes or to use another material.

Which material could you recommend me?


Just my 2 cts ;
Not a smart solution to have tapered holes (say conical ) on top and below your uprights
1/ very expensive to do if you don't have the exact ramer tool
2/ will have play soonly after track use
Fortal which ? 7075?
I have two friends who are both race engineers, they argue about it, one says great the other says no just not, it tends to crack ?!?
He says aluminum 6061 T6
I am confused....

I use racing suspension joints from Carl ts Hischmann, they are tapered.
On my race car, I have big problems with disassembly, nothing gets loose. I can not understand this experience with conical pins.


At the moment I am in the first step in the determination of the lower wishbone.
Therefore, no angles of the steering geometry are determined yet.
Wait, still to come.....
Both of those can be used ; cracks are linked more with how you will distribute tension with your drawing using "spokes" where they have to be

Tapered machining in steel material is not at all an issue ( beside as statedit is more money when done as you draw ; there are others cheaper solutions )
It's an "eventual" problem in aluminium stuff ( electrocorrosion and "matting")
But as usual and as stated before it is your project and your decisision ; I am only giving "humble""" advises
True my previous race cars had steel wheel carriers....
Whereas I've never seen this as a problem, all the sports cars I know use tapered bolts.
Audi R8, Lambo etc....

Better like this? (the load in the FEM simulation is 20000 N)

Unless you will use big diameter and hight angular movment spherical bearing your solution will limit hightly steering angle
you can use tapered roe joint but arrangement have to be different using a "removable"steel insert that you can have it easily done in a lathe and then pressed into top and lower part of the aluminium upright and any way solidly fit when you tighten the end screw of the tapered part



You need more headroom. With the new helmets especially, you will be solidly up against the roof/roll cage structure. Not good.

Chris Kouba

I can't determine from the drawing- is the LBJ a heim joint? If it's loaded with spring force, are you concerned with its integrity?
Nice thread to follow, note that Jac has not commented on the engine shown since you stuck a Ford in your drawings.:p
What country are you in? Your English is improving nicely as this thread moves along
Hi, the frame and the front axle are finished, all FEM issues are done. Does anyone of you maybe values for weight distribution and brake balance for me?
42% Front, 58% Rear, do not have brake balance, dependent on tire & brake combination, presume you intend for sensible combination for those parts.
42% Front, 58% Rear, do not have brake balance, dependent on tire & brake combination, presume you intend for sensible combination for those parts.
Ha - Jac is back ;)
Thank you, I still want to work on the subject of anti-dive.
Do you know the roughly height of the C.G.?
Brake balance still comes, first the steering geometry.
At the moment I still have problems with the topic Bump Steer