Kent2 wrote:
I do want to make the cockpit big enough so regular size people can fit, or even regular American people.
My Haynes is 221, and my American-sized (donkey reference)(6 foot, 220 or so pounds) fits w/o any issues. The driver's butt width (EDIT -- uh, the space in the car, not the width of the human, ed) is almost 20" wide in mine, and 18" for the passenger. For comparison, my kitchen chair is only 17" wide.
IMPORTANT SAFETY TIP -- do NOT measure the width of your wife and/or girlfriend's (donkey reference) when building your car, at any time!!
But then again, my almost same sized frame fit (snugly) into a genuine Lotus Seven S2, which is around minus-3 to "the book" (or 7" shorter, 7" narrower, etc than your proposed frame). It was like getting into a sleeping bag w/o unzipping it, and I don't think I could drive it w/ my shoes on, but.. I fit and I could drive it. I'm betting that a good number of "American sized" people who don't shop entirely at Robert Hall / Lane Bryant would fit into the the original.
How did the Seven do it? Well, first off, the trans tunnel in our builds are, by comparison, massive -- 8" wide at the hip. The original Seven didn't have a frame running down that tube -- it was just a bit of aluminum sheet -- and if I recall correctly, the drive shaft is maybe 2" in diameter, so the entire hump is only 5" wide. EDIT -- the S2 had 16" butt spaces for both passenger and driver. /EDIT The original also had no side padding for your hips -- your butt sits on a "Bench" and you've got the aluminum drive tunnel on one side, and the aluminum/tube side panel on the other.