That's right. The belt is still hooked-up. The electricals are disconnected (easily reinstalled in under 1 minute on the roadside if needed). I have seen quite a bit of discussion here about where the biggest gains come from, unbelting or just disconnecting the field wiring. I was persuaded by the guys arguing that the major source of drag comes from powering the alt., and that it is basically freewheeling otherwise. The powering of the magnetic field to
generate electricity produces most of the drag on the engine, they say.
If you look in my trip log, at the "Aliso" run, beginning in the last few days you will see evidence of what this mod seems to be doing in a high load driving situation. If the log and my estimates are reliable--and it's not really scientific, though quite methodical--I appear to get at least 10% gains on this run.
I have begun to believe that the gain is greater where the engine load is higher: on the freeway and climbing. My "Aliso" run has significant climbing, from near sea level to maybe 500 feet in maybe 5 miles.
Quote:
Originally Posted by oil pan 4
You are spinning the alternator but have cut exciter power right to get your gains correct?
If you picked up about 4% with the alt spinning at no load, that is good.
I think I could pick up 2 or 3 times that with out spinning the alternator in my truck. I expect big gains from a mod like this since the coolant pump is is now electricly driven.
35mpg with a huge truck could be possible.
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