SN95 U/d Pulleys And Amp Issues?

Discussion in '1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-' started by 90lxwhite, Oct 8, 2013.


  1. 90lxwhite

    90lxwhite Mustang Master

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    Hey guys w 94/5 gt's w under drive pulleys did y'all experience an amp loss w them- dim lights etc? My 90 came w em and I had to add a higher amp alternator to compensate. With the stock 130 amp on the sn's is there an issue?
  2. 90lxwhite

    90lxwhite Mustang Master

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  3. Mustang5L5

    Mustang5L5 Car used in adult film "Highway Gangbang-InDaButt" SN Certified Technician Founding Member

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    You don't need a higher amp alternator. At best, you are probably using maybe 100A tops at full load.

    The issue is pulley RPM. The alternator does have a minimum RpM required to output 12v. The underdrives have slowed the accessories down. You need to spin the alt slightly faster to compensate.

    Stock Sn95 pulley is about 2.75". ASP makes ford alt pulleys in 1 7/8", 2", and 2.5" diameters for about $20. You can also use a 2" fox mustang alt pulley. Keep in mind with these pulleys you may need a 5/8" ID washer as a spacer to keep the pulley from hitting the alt case.
  4. 90lxwhite

    90lxwhite Mustang Master

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    Thanks. Prob won't do pulleys on the 95 but was just curious. I don't think they're worth messing with.
  5. 01Laser

    01Laser New Member

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    I think you're right...
  6. 90lxwhite

    90lxwhite Mustang Master

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    They came on my 90, so I can't give a before and after. All I know is its slow w dim lights.., well not so dim since 90 amp alt but u get the gist
  7. mikestang63

    mikestang63 Mustang Master

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    You'll be fine with the proper set. Just don't expect 20 hp as advertised.
  8. revhead347

    revhead347 I have face herpes.

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    If your alternator is not producing good voltage at idle with under drive pulleys, I've found the fix. Put big heads and a giant ass cam on a stroker engine that has to idle at 1000 rpms anyway, and it all sorts itself out.

    Kurt
  9. 90lxwhite

    90lxwhite Mustang Master

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    I'm on it. Tomorrow
  10. 90lxwhite

    90lxwhite Mustang Master

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    You mean they won't make my penis larger?

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