Alternator Cut In Point
Discussion
Tomorrow I will check the pulleys diam on my S to see what is the alternator speed at lets say 6500 rpm (crank).
Modern alternators are made to support 18000 rpm.
http://rb-kwin.bosch.com/en/automotivetechnology/o...
I also have to check what rpm 1990's alternators can support.
Chris.
Modern alternators are made to support 18000 rpm.
http://rb-kwin.bosch.com/en/automotivetechnology/o...
I also have to check what rpm 1990's alternators can support.
Chris.
Good luck with your calculations but at the end of the day they are the pulleys Ford chose ( and they probably spend a bob or two on development) 
I find it easy enough to give the throttle a little "blip" to get the alternator going (and the nieghbours when going on an early Sunday morning run) and all is well (with the car, not the neighbours)
.
I find it easy enough to give the throttle a little "blip" to get the alternator going (and the nieghbours when going on an early Sunday morning run) and all is well (with the car, not the neighbours)
.You are absolutely right, I checked the pulleys to find that the alternator turns two times faster than the crank.If I could find a smaller pulley I will try it.
This is not a priority for me and I can live with that.;)
I am sure that one day, somebody will tell us why this happens on our cars.
Forecast for tomorrow seems ok and I feel like Ill have a ride with the tvr tomorrow.
Which the same for all of you.
Chris.
This is not a priority for me and I can live with that.;)
I am sure that one day, somebody will tell us why this happens on our cars.
Forecast for tomorrow seems ok and I feel like Ill have a ride with the tvr tomorrow.
Which the same for all of you.
Chris.
Gerald-TVR said:
Having changed my alternator recently I have noticed I need to rev to 2000rpm before the alternator starts charging.
My memory (which I very doutful these days) tells me the old generator cut in much earlier, at what point does your alternator cu tin please
Norman
This is normal, mine cut in at 2300 until I modified the circuit. You can lower the cut in speed by putting a larger wattage bulb in the warning lamp or wiring another bulb in parallel with the existing one. I added an additional 1.2 watt panel bulb and the alternator now cuts in at about 1300. I did a more detailed post on this a while ago but I can't find it at the moment. The charge warning panel bulb provides the initiation current for the alternator so the bigger the bulb the more current and the sooner it cuts in.My memory (which I very doutful these days) tells me the old generator cut in much earlier, at what point does your alternator cu tin please
Norman
Edited by Griffinr on Sunday 17th October 22:13
Yep, there is a specific reason why the engine has to be revved (just once) above 2,500 revs or so to get the alternator to start charging. I can't remember what that reason is though.
After that initial "kick-in" rev, the alternator charges just fine all the time, whatever the revs. It's no great strain to give it that initial rev, even if you wait till you're half a mile from your house if your leaving in the quiet hours.
Anyway, the solution is NOT to fit a smaller pulley - all that does is wear the alternator out faster for no real benefit.
After that initial "kick-in" rev, the alternator charges just fine all the time, whatever the revs. It's no great strain to give it that initial rev, even if you wait till you're half a mile from your house if your leaving in the quiet hours.
Anyway, the solution is NOT to fit a smaller pulley - all that does is wear the alternator out faster for no real benefit.
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