Even after final assembly, this racing alternator is not quite race-ready. Durability testing, as well as real-world experience, have identified several areas of the alternator assembly that are exposed to unusually high stresses. These areas are reinforced with a special epoxy, then baked for curing in order to provide additional strength and support. Each unit is then hot-tested for at least 30 minutes in order to provide a "burn-in" of the electronics and to verify output and overall integrity.
The final result is a very dur-able racing unit with predictable output, weighing just 7 pounds. While some manufacturers rate alternator output cold, Bosch units are rated hot, which is, after all, the condition in which they will actually be operating. These racing alternators produce either 100 or 120 amps hot, depending on model. They will actually go into an overload condition (core temperature permitting), up to either 140 or 160 amps, for short periods of very high draw. All are supplied with a V-belt pulley, although many race teams choose to install their own pulley in order to accommodate individual belt/pulley configurations.
The Bosch GCB1 sells for about $2,600. However, with the recent introduction of the new 120-amp version, it's likely that some race teams will be upgrading from the current 100-amp model. As these units come in, they'll be recon-ditioned and made available to weekend racers at a substantially reduced cost.