I just found your forum and I hope I might be able to use it as a resource in my long term effort to design a light weight two seat mid engine roadster.
The main idea being an adapted FWD engine in a steel sub-frame attached to a E-glass monocoque tub with a steel front sub frame carrying the front suspension. Add a little fiberglass bodywork and it will be a full bodied road car with no top and no doors.
The target weight I've had in my mind is 1,400 lbs which probably seems quite piggish by locost standards. I was hoping that by the time my design is almost ready I can find one of the 1.4l eco-boost motors with a twin clutch manumatic that Ford will be putting in small cars pretty soon. It should give good mileage as well as good performance and the manumatic could lend itself to a racy paddle shifter setup.
It's hard to start with an engine that I can't even see, so I'll investigate front suspensions first.
I want donor parts that look nice and are not too overbuilt. With a light car that may be a challenge. The front end will be light with most of the weight in the back. My wheel choice will be as small as possible to reduce unsprung weight, same with the brakes, at 1,400 lbs or less almost any brakes would be overkill because almost every road car weighs lots more than 1,400 lbs.
My first thought was MR2 or MR-Spyder as a donor but when I looked it seems like very normal looking steel arms, nothing sexy about it. Then I looked at Miata, I think it got a nice looking aluminum A-arm setup for 2006 and newer. That's more like it but a front engine Miata has a lot more weight over the front, those arms might be vast overkill. Unless I find a better donor (must be common, probably not any Kei car stuff), I will probably design with Miata arms in mind.
So, I don't know much about Miata parts interchange but I know that Miatas started out really light in 1989 and have gotten heavier as the years went on. One web site seemed to think that the 2006 style spindle was an FWD design taken from the parts bin. So what can interchange, what is lightest and what is bulletproof? Could 2006 arms on 1989 spindles be a good light weight setup?
Thanks for the help.