At all times, the way weight is attached to the kart must conform to the Karting Australia Handbook.
Adding Weight to the Kart
So what does all this mean ?
Endurance racing requires multiple drivers with different body weights to race on a circuit for an extended period. At all times teams must be above the minimum weight limit for the class. For Subaru Endurance Racing the class weight is 175KG Kart & Driver. In order to achieve this, weight can be altered during the race at pitstops.
The first thing to do is bolt as much ballast as possible to the seat and chassis. Do this by adding enough weight to the kart to ensure your heaviest driver meets the minimum weight requirements. Remember also, a full tank of petrol weighs about 6.5KGS, so work this into your strategy.
There are two legal ways of quickly altering weight during an endurance race;
1. Weight Canisters
Weight canisters must be firmly attached to the chassis at two points. They can be made of a combination of metal and heavy plastics. The weight canister must have a lid or device that ensures the lead ballast cannot rattle lose during competition.
The advantage of the canister system is teams can make up specific weights to add for each driver. Teams can also add specific weights based on the fuel load at the time.
2. Seat Inserts
Seat inserts must be retained by two mechanical fixings. These fixings should ideally attach to the chassis, however attachment through the outer fiberglass seat is also acceptable.
Inserts are made by using a fibreglass inner kart seat and attaching lead sheeting to this insert.