Radiator New-Line Hobby 430 x 120 x 40 mm cpl. with support

The Hobby model for karts by New-Line is not a main radiator but an add-on: it is mounted together with the radiator, but in a different spot to increase the overall efficacy of the engine cooling process. The Hobby in fact receives boiling water as soon as it comes out of the engine: its function is to lower the temperature as much as possible before water enters the main radiator and undergoes the standard cooling process obtained by air hitting against the grid, after which it is cold enough to return into the engine.
The radiator is made like main ones, with an aluminum cap to let water in and with top and bottom chambers. But compared to a regular radiator the Hobby is much thinner (12 cm wide) and is mounted on the side of the engine, to the right of the pilot. This way air used in the water cooling system is harnessed from both sides, which improves cooling capacity in hot weather.
The Hobby was originally produced as a small radiator for single-brand and amateur categories and was then adopted as an add-on to RS and Big kart radiators by New-Line. It can be used in all categories, though it's advised for the KF1 and the KZ shifter.