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Overdrive alternator pulley question.

  • Thread starter Thread starter DaveL
  • Start date Start date Oct 5, 2004
D

DaveL

Founding Member
May 10, 2001
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NYC
Oct 5, 2004
#1
  • Oct 5, 2004
  • #1
Is it possible to overdrive an alternator too much? Does anyone know what the stock size alternator pulley is as well? I'm thinking of getting a 70mm pulley.
 
W

wytstang

Mustang Master
Mar 14, 2004
4,988
4
78
Summerville,SC missing South Fl. weather :(
Oct 5, 2004
#2
  • Oct 5, 2004
  • #2
70mm is an underdrive pulley. The over drive pulley is 56mm.
 

mystang94gt

New Member
Jun 14, 2004
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Bay Area, CA
Oct 5, 2004
#3
  • Oct 5, 2004
  • #3
Not sure about the stock size but that seems HUGE imo. I think the one on my Alt (u/d one) is like 50mm at the most.
 

mystang94gt

New Member
Jun 14, 2004
951
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Bay Area, CA
Oct 5, 2004
#4
  • Oct 5, 2004
  • #4
wytstang said:
70mm is an underdrive pulley. The over drive pulley is 56mm.
Click to expand...


Really? Damn I must be tripping. I looked at my ruler and thought 70mm seemed way to big.
 
W

wytstang

Mustang Master
Mar 14, 2004
4,988
4
78
Summerville,SC missing South Fl. weather :(
Oct 5, 2004
#5
  • Oct 5, 2004
  • #5
mystang94gt said:
Not sure about the stock size but that seems HUGE imo. I think the one on my Alt (u/d one) is like 50mm at the most.
Click to expand...
That can't be right. The bigger the pulley the slower it turn hince underdrive. The smaller the pulley the faster it spins hince overdrive.
 
W

wytstang

Mustang Master
Mar 14, 2004
4,988
4
78
Summerville,SC missing South Fl. weather :(
Oct 5, 2004
#6
  • Oct 5, 2004
  • #6
GO to this link scroll towards the bottom it says underdrive Cobra R pulley 70mm right under they have one for sale as overdrive 56mm http://www.mustangparts.com/engine.htm
 

mystang94gt

New Member
Jun 14, 2004
951
0
0
Bay Area, CA
Oct 5, 2004
#7
  • Oct 5, 2004
  • #7
wytstang said:
That can't be right. The bigger the pulley the slower it turn hince underdrive. The smaller the pulley the faster it spins hince overdrive.
Click to expand...

Well your right about that. I just couldnt picture a 70mm pullie on my alt. I'm on my way out the door so I will go measure right now. LOL.
 
D

DaveL

Founding Member
May 10, 2001
320
0
0
NYC
Oct 5, 2004
#8
  • Oct 5, 2004
  • #8
wytstang said:
GO to this link scroll towards the bottom it says underdrive Cobra R pulley 70mm right under they have one for sale as overdrive 56mm http://www.mustangparts.com/engine.htm
Click to expand...

Dang I need glasses cause that's the exact page I was looking at! Thanks.
 
M

mackey

Active Member
Jan 25, 2003
1,284
1
38
Beverly, Massachusetts
Oct 5, 2004
#9
  • Oct 5, 2004
  • #9
I would never overdrive my alt. I blew up two in one week at New England Dragway. Good thing the one i bought has a lifetime warranty. The first one, just stopped charging (bad diode). The second one had the voltage regulator go, and cooked the battery at 18+ volts and the battery literally exploded acid everywhere.
 
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