Does anyone know much about this conversion. would it be to firm for a street car etc etc?

www.minispares.com/Product.aspx?pid=36782

I'd ask your question on the MiniMania forum, http://www.minimania.com/msgthreads.cfm
These springs were designed in US.
Some people say they do give problems.
people either love em or hate em....

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

I like them, but they can be a pain. Here is a pic for you.

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*Reasonable pricing
*I come to you..
Jay: 0431404607

in what way can they be a pain..... i think i will post it on the MiniMania Forum

The mini suspension set up does not lend itself to using coil springs in place of the rubber springs. The lever ratio of the suspension requires a stiff spring with a short travel. To achieve this with a steel coil spring requires a low number of active coils and a thick wire diameter.

Manufacturing coil springs is a process that requires very tight control so that there is very little variation from spring to spring. In my experience, spring manufacturers struggle to get the number of active coils to be exact across a number of springs. The number of active coils is the number that deflect under load so it doesn't include the ones flattened, closed and ground at each end of the spring. It is hard to control due to the way that the hot wire is wound on the mandrel during manufacture. This is not really an issue for a spring with say 10 to 15 active coils like on a coil-over conversion or 5-8 on a modern road car spring. A difference in 0.2 active coils on a spring with 10 active coils is only a 2% variation in spring rate across springs.

The mini replacement springs appear to have only 1-2 active coils so a variation of 0.2 is a 10-20% variation in spring rate. This would be noticeable on the road. These springs must therefore be made very well to be consistant. Having seen them, they appear to be made quite well, but not as well as some other brands. Of course, old rubber cones would have a very large spread in rate across different cones.

The other issue with these springs is that they are short and, like a rubber cone, could fall out if the suspension is allowed to droop too far. This means that the spring needs to be held in place by straps or ties or the suspension droop needs to be controlled by shorter shocks or droop straps. Some sort of pre-load spring like the flat coils used in some progressive rate, two spring units (Eibach I think) would improve this but make them even more expensive.

In terms of whether they improve the handling, it is their linear rate that is the difference. The spring rate does not change with deflection, unlike a rubber spring which has a rising rate characteristic. The way this affects the handling would lead to some people preferring them and others preferring the rubber cones.

Oh, and they have no internal damping, unlike the hysteresis in the rubber springs. The dampers would need to have good high frequency control to have equivalent damping. This would be a minor issue more related to transmitted road noise and vibration than handling.

M.

(please treat this like all other free advice on the net, with caution, until verified independantly)