GT-500-270XP High Output Alternator for Ford Mustang with 5.4 DOHC
GT-500-270XP High Output Alternator for Ford Mustang with 5.4 DOHC
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Base Price: $639.95

Price with Selected Options: $639.95

Product Code: GT500-270-XP



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The Large Case Denso Hairpin 270 Amp XP series high output alternator is a component of a next generation high efficiency, severe duty charging system specifically engineered for DC Power Engineering. This system consists of a 270 Amp alternator and internal regulator. The alternator produces a maximum of 270 amps and will produce a minimum of 170 amps continually at low idle speeds and maximum output above 1800 engine RPM. The alternator has a maximum efficiency in excess of 75 percent. The rectifier is mounted onboard the alternator and consists of 12 50 amp press fit diodes. The brush holder assembly and slip ring are environmentally protected and the bearings are heavy-duty, oversized premium bearings. The alternator housings are precision-machined cast aluminum and all components are of OEM quality. All major components being carefully chosen for maximum performance and reliability.


This new charging system features an advanced proprietary stator winding of a new design that maximizes efficiency with near 80 percent sectional density of the winding coupled with very low coil resistance. This gives the alternator maximum low speed output, as well as a 90% reduction of magnetic pulsation with the stator windings built in cancel circuit to minimize electrical noise. The internal regulator is a proprietary design advanced multifunction digital regulator that completely integrates into the vehicles PCM through the OEM wiring harness to retain all vehicle specific functions such as internal temperature compensation, lamp terminal monitoring, load response control, and alternator load factor.


The Large Case Denso Hairpin 270 Amp XP series alternator is specially designed to mount directly in the OEM mounting location with no modification. All electrical connections shall be in the original locations. The alternator features a custom machined drive pulley for increased output at idle speeds and retains OEM belt length. The pulley is 7 Groove Hard Anodized 6061 Billet Aluminum and hard anodized coating for wear resistance and durability.


The Large Case OEM alternator is rated at 130 amps with 80 amps at idle. The supplied alternator makes 190 amps at normal idle. The vehicle needs a maximum of 100 amps to supply existing electrical loads with all accessories on leaving little room for additional accessories. The supplied alternator will supply an additional 90 amps of available output at hot idle output, and 110 amps additional at cold idle output, and up to 140 amps at highway speeds.


The Large Case Denso Hairpin 270 Amp XP series alternator is manufactured to the highest quality standards in the USA with premium USA made or sourced components for the highest quality possible. All of our high output alternator's parts are carefully chosen for the maximum durability

Mounting Type Direct fit to OEM Mounting
Output Voltage 14.8
Idle Amperage 190
Hot Idle Amperage @ 200F 170
Max Amperage 270
Hot Max Amperage @ 200F 240
Positive Output Stud Size 8MM x 1.25 Copper
Temperature Compensation Yes with 3-Step Thermal Protection
Rectifier 12 50 amp press fit diodes
Rectifier Heatsink Aluminum
Pulley 7 Groove Hard Anodized 6061 Billet Aluminum
Doesn't affect vehicles PCM, Check Engine Light or Charge Light Yes - w/ Supplied Adapter Harness
Warranty Duration 2 Year Standard Replacement
SKU GT500-270-XP

Average Customer Review: Average Customer Review: 4.5 of 5 4.5 of 5 Total Reviews: 4 Write a review.

  0 of 0 people found the following review helpful:
4 of 5 Alternator May 28, 2022
Reviewer: ROLF SJOLUND from HARNOSAND, Vasternorrland Sweden  
Rocketfast shipping and works great
Only four stars due to wiring

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  0 of 0 people found the following review helpful:
4 of 5 Rquires modification March 24, 2021
Reviewer: Anonymous Person from Southern California  
Not exactly a factory fit on 2007 GT500. Alternator connections will need to be extended as they are 8 inches to short as the connections on the GT500270XP are rotated clockwise from the factory alternator. The power post also  runs into a stainless line that will require modification to prevent a direct short.
Got it all installed and works great.

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  0 of 0 people found the following review helpful:
5 of 5 GT-500-270XP High Output Alternator September 26, 2019
Reviewer: Robert Jernigan from Clearwater, FL United States  
Great alternator so far. Bolts right in, perfect fit. I bought the wire kit to go with it and I am glad I did. I read about this company on a Mustang forum in search for a high output alternator for a GT 500. Turns out the 09 is a oddball but Nations had it! Would buy again! Highly recommend.

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  0 of 0 people found the following review helpful:
5 of 5 Great quality, easy fit April 23, 2019
Reviewer: Robert Mels from The Netherlands  
Decided to replace the stock alternator after stage 3 tuning and additional power consumption. The stock alternator could not maintain enough voltage on idle and low revs. Ordered the GT500-270XP and three days later it arrived in The Netherlands. I ordered the optional cable kit, but I decided to go another route with the 35mm2 cables.
Fitment is great and now I have 14.3V on idle. Would recommend the Nations alternator!

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