Comparing Dimensions

I've been reading the excellent Lotus Seven & the Independents, and one thing I'm struck by is how much variation there is in the critical dimensions of various Sevenesque cars.

I've compiled various measurements for the two common Locost platforms as well as for three baseline Sevens and a few lightweight sports cars. I've also thrown in weight and horsepower numbers for reference.

Car	Overall			Track		Wheel base	Ride Height	Weight	HP
	Length	Width	Height	Front	Rear
1962 Lotus Super Seven Series II	131.5	56	39.5	47.5	48.5	88	6	924	85
Haynes Roadster (Gibbs)	129.5	67	46	56	57.5	94	3.9	1309	105 est.
Keith Tanner's CMC Miata-Locost	128	65.5	42.5	51 est.	56.2 est.	92	4 est.	1279	175
FM Westfield	131.5	63.4		55.5	56.2	91.5	5.75 est.	1300	125
2006 Caterham CSR Superlight	129.9	66.3	40.0	59.3	57.7	91.1	3.9	1245	260
1993 Mazda Miata	155.4	65.9	48.2	55.5	56.2	89.2	4	2222	116
1974 MG Midget 1500	141	60	48.3	46.3	44.8	80	4	1631	65
2003 Ariel Atom II	134.3	70.8	47	63	63	92.3	3.5	1005	220
1957 Lotus Eleven LeMans	139	60.5	31	45.5	47	88	4.5	1360	84
2000 Lotus Elise	147	67	45.2	56.7	57.9	90.6	6.3	1574	143
1964 Austin Mini Cooper S	123	55.5	53	52.8	46.9	80	6.3	1250	70

Click on the car's make and model for the sources for my data.

The first thing that jumps out to me is how tiny the original Seven Series II is. The Caterham is nearly 10" wider than the original car. Of course a lot of this is wider modern tires, but it's still significantly smaller than anything on the road.

The other thing is how much longer the wheelbase is on Gibbs' Haynes Roadster vs. every car in the table. If you look in the Haynes book, the front wheels actually stick out past the front of the nose cone! Since my frame design is based on the Haynes Roadster, reducing the wheelbase to 90-95" is going to be one of my design priorities.

I'm going with the stock Miata front and rear track on my Locost (as of right now), so the width of my finished car should be in-tune with the rest of the pack.

Update 6/22/08 - Chris Gibbs has contacted me with corrections to my table. It appears that the figures I had before for the wheelbase were way off, as many have commented. Now with the correct dimensions, it appears that the Haynes Roadster isn't as big as the discussion forums would have suggested. This makes me feel much better about using the design as a starting point!

Update 4/14/09 - It appears the Haynes Roadster wheelbase figures are in dispute again. I've received word from a reader who very adamantly states that the wheelbase is actually 94". The reader states this is what he got in CAD when modeling up the frame. Gibbs himself on his forum states it is 92", so I'll chalk that up to the book not completely representing the actual car.