As many of you know I purchased a Lotus Seven replica called the WCM Ultralite S2K late last year to make it a street legal track toy. While the Ultralite may maintain the spirit of the original Seven, as you can see below, it has a distinctly different shape and has generally larger dimensions to accommodate drivers of all sizes. In order to move this extra bulk (relatively speaking) around it comes with the incredible F20C engine out of the Honda S2000. The end product has some astonishing performance figures:
Weight: 1300 lbs
Horsepower: 240 bhp
Redline: 9000 rpm
Power to weight ratio: 400+ hp/ton
0-60 mph: 3.5 seconds
My particular car was the first prototype built by World Class Motorsports and is the actual car used in most of the magazine tests. The original owner of the car then sold it to an active PCA member who took fantastic care of the car and documented his changes. He also had the car made street legal under the California SB100 exemption for kit cars. After a few years he ended up selling it and the car went through 2 other owners before I found out that it was on sale again and jumped at the chance.
The first and most immediate thing that hits you when driving the Ultralite is sheer mind-blowing acceleration. When I bought the car it was on a set of fairly old 235 width Falken Azenis. Now while the Azenins are actually pretty good tires for autocross, they have nowhere near enough grip for the ridiculous horsepower of the Ultralite. The very first time I tried a hard acceleration run I spun the rear wheels in 3rd gear and got a full on fishtail moment at 60+ mph. This is the only car I have driven where you have to rev match on upshifts or the rear wheels will happily lose traction 
Even within the same gear the acceleration is phenomenal. The car pulls pretty strongly below 6k rpm but once you go above the 6k threshold the VTEC cuts in an it feels like someone has hit the fast forward button. Plus with the 9k redline you have plenty of time in the powerband and dont have to keep rowing the gears. Also despite the fearsome power, I do have to say that the Ultralite is actually a very benign handling car. The rear gives you plenty of notice before it steps out and you can easily use the throttle to play with oversteer through the bends (see opposite lock below 
).
Driving the Seven is very visceral experience where you can see, feel and hear every mechanical thing on the car. While you are “one with the road” it is a very different experience than what you feel in a Lotus Elise. The Elise is delicate, nimble car and will eagerly follow your every command while the Ultralite is like a raging bull that you have to manhandle into position before you step on the throttle and hold on for dear life. It is very much of a “mans car” where the controls are very heavy and you end up smelling of oil and gasoline after every drive.
While the car was in running, registered and mostly-drivable condition when I bought it, I nonetheless had several improvements in mind before it would be truly track worthy. While this car is likely to be a project car for the rest of my life, for the more immediate future I plan on a series of “Setting up a Seven” blog posts about work I have already done including the safety setup, wheels/tires, exhaust, suspension, etc… In the meantime enjoy this video of Rob doing a run at the last Lotus Club autocross of the 2009 season.
video by cxcheng
