I have been doing what you want to for years now, and I am not sure you know what you are getting into...

To start off, if you are going to design your own suspension, then start your homework. Why are you wanting to get away from a Mac Pherson setup? There are a number of reasons why you might, but you will want to understand the pros and cons to each. If you go to a dual a arm, then you have options of parallel, non parallel, equal length, unequal length, and have to understand the pros and cons of those alone, etc. Getting your caster, camber, KPI pneumatic trail, and scrub radius correct is a pain in the ass. Steering rack placement is also of utmost importance. Some programs that you can use are Susprog for your suspension kinematics. Its inexpensive and relatively easy to use. Its what we have been using for 9 years now. Susprog will provide you will the tools that you need to design these systems, but its up to you to understand the values that it provides. If you use all stock components, then much of this is unnecessary.

As far as the tube chassis goes, you will want/need to do finite element analysis if you want to make that chassis light and strong. Choose your material whether its 4130 or mild. Intelligent tube placement makes a world of difference, as does tubing diameter (remember that diameter is where the strength in a tube is, not nearly as much as wall thickness).

The program that you can use to do all this is Solidworks. The program is amazingly powerful and again relatively easy to use once you get the hang of it.

The next issue that you run into is tooling. Getting a tube bender, optical table and a decent MIG/TIG is expensive enough. And I couldn't build anything that I design without my lathe and milling machine either.


Good luck with your project. I am unsure as to your knowledge and skill level, so please don't take anything that I have said the wrong way. Many people do not go to this extent, but IMO if you want to do it and do it right this is the only way. I have seen many hack jobs before that just made me cringe. Shit, just today I looked at the suspension design on an old British Jensen and just laughed, and it was a production car nonetheless!