Very Cool. We are also racing endurance machines at Electron Raceway here in Oregon. We are also running a mix of H plate chassis. However we are running these machines with Deathstar or ProSlot 16D power and adding custom front and side pans to improve handling. Check out the link for CanAm cars http://slotblog.net/...raceway-can-am/
and for endurance machines (we call them Gran Sport class) http://slotblog.net/...way-gran-sport/
For a frame of reference on speed a bone stock Scaleauto (no pans with a stock motor) turns about 5.75 seconds per lap. The Can Am/Gran Sport cars are running a bit less than 5 seconds. The 917 has run 4.75
We have found that the best car in these classes is the Porsche 917. It is very wide front an rear and very low.