[Speed Daemon]

With Tomy AFX you could achieve 10 lanes or 12 for just an oval, the problem would be to get power to the inner lanes. We used to run 6 lane tracks and I have adapted start straights to power the inner two lanes as well as power boosters for longer circuits. 

I used to build tracks in a similar small space, 4 lane tracks work ok but remember that you will need 4 drivers and at least one or two marshals unless you decide to drive at a speed that you will not come off! (Never happens) You can also send the track vertically up a wall, the only limit is your imagination!

I have just restarted racing again after a 13 year break, we had a 70 feet 4 lane track at the local pub, with a lot of banking, very fast! I have over 1000 feet of track, so the limit is the size of the hall we can hire. Check out my website click here

You would probably be better off trying to get to an established club as suggested above, I think your ambition should be applauded but you should reign it in a little to meet practicality!