The track is a 1/4mile clay oval surrounded by a concrete wall and heavy fencing.
Rules for the cars are (in short):
max capacity 248 cid . This is a recent rule change in regard of engines in use, for a long time it was 240cid to suit the flathead ford v8 overbored, widely used in the 60s-70s. Then various small block and 6 cyl fords, destroked chevs, chrylser 6's were used. Finally in the last 8 years or so an aussie ford i6, toyota v8 and nissan v8s became very popular, and the capacity was enlarged to move with the times.
induction must be by 4 barrel carb, fuel is petrol usually avgas.
Min weight 1400kg, max 1500kg.
Most of the rest of the rules related to weight, dimensions, bumper construction, roll cage construction, belting and seat construction... watching these hit the concrete retaining wall headon, sideways or rearwards at 90mph with another car pushing makes you cringe a little. To watch one drive away afterwards is amazing. When pushing and shoving or ploughing an opponent into the wall to immobilise or roll them is legit and encouraged you are garrenteed a spectator sport. Bones broken by the impact are common, ribs, shoulders etc. my previous employer suffered a broken spine on what was meant to be his last race. Dissy caps are strapped and banded into place as they will literraly shatter on impacts as the engines are solid mounted. Everything must be secured, and not lightly.
In a normal race these cars lap the 1/4 mile clay oval in about 16-18sec, not bad considering the weight. In the NZ national teams racing event held annually over 2 nights only 15km from where i live the format is simple. 2 teams of 4 cars each line up for a standing start, 4 rows of 2. After the lights go green the first driver to complete 10 laps wins the race for his team. You may only drive anti-clockwise round the track. Its a very destructive form of racing, and a real spectator sport, especially when everyone there has a team to support. Im getting a bit OT ... but ive been waiting 49 weeks and the excitement is building :D
They seem to run fine on a 4brl and the biggest spenders are making 600+ hp, (and spending $60k+NZ). Most are 450-500hp and use only one gear while racing so vary thru the rev range quite a bit. The quad cam v8s are noticably easier to start and almost easy to drive around slowly, unlike the older iron block engines which where in states of very grumpy tune. Bryan hartley builds many of the engines used in these cars, and has a rep for building engines which will last a season without overhaul, some of these suffering overheating during the season but still going strong. Some of the credit must go to nissan of course. The engines that havent been hot often need only bearing shells and rings between seasons. Also OT - to give toyota thier due the 1uzfe has proved as able as the nissan and wins races against them.