Well... it's been a while since I updated this thread...
The E-kart has taken us a bit longer to complete than we expected (like a year) - but it's done! My son was in a full leg cast for 4 months, and had rehab for another 4, so we got behind on the project. The shop that was bending the 4130 Chrome moly tubing last year screwed-up, and didn't get us the tubing on time, but I don't think there would have been any way we could have gotten it all cut and fitted in time anyway.
It took quite a while to notch and fit the cage tubing to satisfy the rules, but it should be legal. We had it professionally TIG welded, and that alone took the welder almost 4 hours.
We added another battery (behind the seat) for 48V, and picked-up another 1000 RPMs and more power. Top speed has been 48 MPH, but that was in the neighborhood. Should be faster on the track's 1mi+ straights.
Here's a picture from today -
Competition is this Monday (5/13/13) at Road America. I'll post results as soon as possible.
Jay