Not that there's anything wrong with a dyno meet, but I'm thinking of other options to throw on the table:
How about some kart racing at New Jersey Motorsports Park? Look at this page on their site:
http://www.njmotorsportspark.com/karting.html
It's 1 hour from Philly. For example:
Mini Grand Prix: $80.00
Day License and all equipment will be provided. Groups
of 8-12 will be racing on one of the Club Tracks. Event will consist of (3) 10-lap races followed by a 12-lap final.
Groups of 13-18 will be racing on one of the Pro Tracks.
The race format will consist of (3) 8-lap races followed by
a 10-lap final.
There's another kart track near Allentown that I hear favorable reports about, but I've never been there.