Alternator upgrade (?) Mitsubitchi from 2004+ Police Crown Victoria

Discussion in 'V8 - Performance Upgrades' started by GEN 3 SHO FAN, Jul 16, 2017.

  1. GEN 3 SHO FAN

    GEN 3 SHO FAN SHO Member

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    I just replaced (another time) my alternator, very funny to spend a summer week-end to do this...

    As I have now 2 toasted 4G alternators, I making searches to rebuilt one with the 2 but I found some interesting infos on Ford alternators. (On the first, the bearings failed, on the second, even if it was recently rebuilded, diodes failed.)

    I found a link explaining that Crown Vic used 4G (same as our with 130 amp) and 6G alternators. I'm not sure on which parts 4G and 6G differs but I'm almost sure that a 6G can be fitted into a 4G casing (not usefull however as the output is similar).

    Between 1998-2002, these 2 alternators use differents connectors but with the same wiring. They seems very similar in shape but the "casing" is different to fit on Crown Vic 4.6 motor.

    And in 2004, police interceptors received a high output Mitsubishi alternator of 190 amp. The casing is different but must have same dimension than 6G probably (same bolting).

    The reason why I'm checking this it's because our alternator eat a lot of heat placed at 2 inches from the rear exhaust manifold (even with some sheilding) and it toasts parts in them. The link give some performance graph of the power output at some different temps. The more it's hot, the less is electrical power output... Let's see (6G and Mitsubitshi) :

    03policegraph-vi.jpg 04policegraph-vi.jpg

    http://www.idmsvcs.com/2vmod/alternator/wiring/diagrams/index.html

    I don't know which temp we have there but it's really hot. I can expect easely a lost of 30% of the power in summer time. However the power need stay the same and it's probably the cause of failing alt (they work more on a SHO rather than on a Ford Expedition (same 4G) where they are on front top of the motor).

    Then, I'm wondering if fitting a Mitsubishi is possible and can be considered as a maintenance upgrade as it will works less if the output is better.

    Anyone tryed to fit Mitsubishi alt internal parts into a 4G casing before or have an idea if it's possible to switch the case of an Mitsubishi alt into a 4G alt ?

    4G 2.jpg Mitsubitshi police.jpg

    Thanks for infos,
     
    Last edited: Jul 16, 2017
  2. GEN 3 SHO FAN

    GEN 3 SHO FAN SHO Member

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    After some more searches, it's appears we have to change the megafuse (175 amp) to a bigger one and maybe change for a bigger wiring to handle tha added amps.

    Another guy elsewhere had a good idea : replace the alt pulley by a smaller one to override it a little. I already observed that some 4G alt (on differents Ford models like Windstar) had smaller pulley like 1/4 inch smaller on diameter... I think it will not be enough to permit the strap to slip (if your tensionner is good). Sadly, my alt is already bolted (and I don't have another week-end to spend on this). :S
     
    Last edited: Jul 16, 2017
  3. gamefanatic

    gamefanatic SHO Member

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    Well, I have replaced the Alts in both of my SHO's at this point. Both were covered in years of grime too... Being they were both OEM and nearly 20years old (at the time), I'd say they worked as designed. However, if you put in a stereo system that is going to draw more power, you are going to need to upgrade the Alt like you are mentioning. Never thought about swapping the internals from another system. Not sure the benefit if there is a lot of custom work involved with that, as opposed to just going to an aftermarket company. You may pay a little more, but it would be plug'n'play. I replaced all of mine with the AutoZone Duralast Gold's and have been able to forget about them. Those are the models that are all new, and may even include design fixes...

    Yes, many people looking at upgrading their electrical system forget that there are many other components that may also be involved. Your primary cabling may need to be upgraded (the grounds and primary positive), in addition to the fuse. Adding a slarger drawing stereo may also require upgraded power, or new dedicated power lines. Adding an additional battery for these systems also brings it's own design challenges...

    As far as heat and issues are concerned, also think about the fact that the factory battery is stored in the engine compartment... Relocating it to the trunk can help the longevity as well as give more room up front for things...
     
  4. kevinspann

    kevinspann 87 Octane

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    The 3.8 Windstar alternator from the same era as the V8 (96-98 I believe) fits and works in a V8 SHO. I believe the 99-03 Windstar 3.8 alt is a 6G model that in theory should bolt in place of the stock 4g alternator - bypassing the fitting of different internals into the stock case. I haven't been able to actually test this out, but I think it would work, with the wiring changes needed for it to function correctly.
     
  5. gamefanatic

    gamefanatic SHO Member

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    From what I can see at RockAuto's pictures, the electrical connections would need to be changed, and validated that there is no difference in the wire layout. Other than that, just need to upgrade the main fuse. The holes look about the same so it's probably going to bolt right up.
     
  6. GEN 3 SHO FAN

    GEN 3 SHO FAN SHO Member

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    Alt 4G aren't so difficult to find, but they are a PITA to install.

    4G and 6G seem very similar but no upgrade (same output). I don't know about internal differences between them, there is an upgrade there ? (My goal was to switch to Mitsubitchi.)

    I have not added a sound system in the car, I just want to have a little more output to give a chance to this alt. I also rode that OEM power output is 15% more than indicated because the companies want to be sure they correspond to standards (130 amp is in fact 150 amp if you test them...).

    I think now a smaller pulley can be a great idea because it will not generate enough power to modify all the line (1/4 smaller on 2.5 or 3 inches). I took a photo of the 2 side by side.
     
    Last edited: Jul 17, 2017

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