Jump to content

Rear control arm fabrication

Recommended Posts

So here is one of the mods I am working on now! This will be mounted to the floor inside the car using the existing mustache bar mounting points. Shocks will be monoshocks from a motorcycle. Does anyone have a computer program to calculate what the length of the upper control arm should be? Should it be parallel to the lower C-arm? Ideas?




Link to comment
Share on other sites

My understanding of control arms is that the length relationship between upper and lower doesnt really matter, the most important part is that the outer pivot point be parallel or behind the lower pivot point or you will introduce positive camber when the wheel goes up. I'm sure someone will chime in with a more scientific answer though.

Link to comment
Share on other sites

You can make the handling real funny if you don't get things quite right, in short, the position and length of everything has some effect.


I believe there is a trial version of this program.






If you're going to do something as drastic as this, you might want to pick up a copy of Racecar Vehicle Dynamics.

Link to comment
Share on other sites

Any Ideas how much camber change/in. of travel should be designed into the system?


Car will primarily be used for Hill Climbs, AutoX, and occasional street joy rides(will be street legal).


Take my advice with a grain of salt (or a few pounds as the case may be). You haven't mentioned tires and that's the first thing I'd look at. Try and find a car that uses the same tires and see what they are using for camber gain. My gut feel is that 50% recovery from roll is too much. I'm guessing that it's going to be in the 20 to 30 percent range. If you have too much with modern radials it will give you snap oversteer. And the way you'd end up fixing it is running really stiff to keep thing from moving.


With regards to motion ratios you will want to keep those very close front and rear. That will make shock tuning much easier. And I'd also make sure you're new rear suspension moves the RC in such a way that the car tends towards understeer on corner exit. If you can think about having some adjustment in the rear for RC height as that can be a powerful tuning tool.


Hope that helps,



Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...