Tim Keith

I'll probably be safe and stick to someone else's engineering. From a practical standpoint it's my intention to use existing components, not simply because they are proven, but because existing parts are *much* cheaper than dealing with race car engineering shops, especially when I might have to place more than two orders to get it right. There are racing applications such as mini-Sprint cars that fall into my weight goals. It'll be wiser to do 1-800 credit card, but I probably have to keep changing rates until the springs are precise. A lot of this stuff is sold on ebay. There are some "new" thirty year old Porsche torsion bars on Ebay with a current bid of 99 cents. I wouldn't want to guess how much a custom spring shop would ask to make a set. Motorcycle torsion bars are probably nearer to my requirements. Ich Bin Ebay'r. I have a neighbor who makes all sorts of non-spring things from leaf springs from junk cars, a torch with a big hammer. Springs are pretty good metal to hammer into things. Thanks Tim

Even if it's only a prototype spring, I would like to try. When I work out the spring rate, I would probably find a shop to make the springs. The application is a 1,000 pound car based upon a Lotus Seven. I don't know who might sell torsion bars for such a light weight car. It would be prohibitively expensive for me to order custom springs as a "guess". I suppose springs from a motorcycle might work, but it might be hard to match the rate needed. Or torsion bars from an junkyard might be turned down on a lathe, then heat treated? I figure if I build the car, I'm already taking my life in my hands. Especially in a 1,000 pound vehicle, more or less the size of a 1948 Crosley. Thousands of "Locosts" have been built with coil springs, few with torsion bars. The torsion bars are used to mount the suspension inboard of the body shell (it's space limited so that coil springs will not fit). The inboard springs reduce wind resistence. The "Locost" suspensions are typically hand built, as is also the case in many hand built motorcycles. A lot of folks are risking their life in building these mini race cars, once tested *most* Locosts have few problems. I'd probably use an OEM Honda suspension in the rear. Sorry, not much of this post is blacksmith related - the entire car is a study in metal working, it's a stressed space frame with triangulated welded tubes, more like a 1940s airplane than car. Tim

Can a torsion bar spring be made in a simple forge, assuming I have the correct type of steel? I know little about metalurgy. In a particular application I would like to use a torsion bar instead of a coil spring. I figured someone here would know how to make these. Some torsion bars are hollow, a solid bar is OK for my use. The spring would be used in the suspension of a light weight automobile, it would probably resemble springs used in motorcycles. I try to rely upon parts that I can find in salvage yards. Some of my design ideas don't have appropriate off the shelf parts, it can difficult to find a spring with the precise capacity that is needed. Tim