classicretrofit Posted April 24, 2020 Posted April 24, 2020 For our all new 6 phase alternator, we chose to use Denso 6 phase 'hairpin' internals. These units are in widespread use and have been designed to support the high loads of modern vehicles with all the gadgets and stop/start systems. The units are highly efficient and generate very little heat which is the killer of rewound Bosch or Valeo units. They have internal cooling fans too. The major work was in designing a casing to fit the 911 fan shroud of which there were 3 variations over the years. The unit will fit the earliest fan housings without modification and the later years by using a spacer. Some changes to the wiring are needed in the car, namely the positive and negative cables to starter and engine case need uprating to 25mm cable ( 4 AWG ). Although the unit is rated 180A, it is unlikely that a single pulley would be capable of transmitting that kind of power. Internet wisdom suggested that a single pulley limit is around 120A but we test everything first hand. Our initial testing included running the alternator at 140A with no pulley slip. The unit produced 90A at 950 engine RPM , falling slightly when warm. To put this into context, a 964 110A unit only produces 40A at idle. Success with our prototypes was great news for electric A/C and also for electric heat, several versions of which have been in testing and development for a while. There is no clear winner on electric heat as yet!
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