More Horsepower?

3 posts 2 contributors 884 views

Member since Jan 2012
13 posts
Henderson, NV, USA
1 vehicle in the registry

Jan 16, 2012 at 3:04 PM

If I replace the 200Amp alternator on my 08' CVPI with a 135Amp, would it cause less drag?
Are there any problems associated with doing this ? (no police lighting on car)
If there is less drag on the engine, is it worth the savings in cost ? (they are substantial)
I checked, and there are units that put out 135A and are meant to fit my car. I just don't think I would need a 200A alternator for civil use.

Rev. Edward Lister

jdmeaux

Member since Jan 2009
525 posts
Lafayette, LA, USA
1 vehicle in the registry

Jan 16, 2012 at 7:08 PM

Unless you are trying to push a big amp for your stereo system or multiple amps, you can go back to a 135 amp alternator. The 200 amp alternator was installed for the lighting system.

No, it will not make a difference in the drag on the engine. Nor in fuel mileage.

*******************
PROUD MEMBER of www.crownvic.net

It's just a SUPER-DUTY Mustang GT Sedan. 198K miles and still rolling HARD.

1997 Crown Victoria P71 SVT *** ex-US Marshall service (the CAR)
STOCK?? I bet it was modified.

13.26 @ 107.24 MPH 1/4 mi w/ me, tools, & full tank of 93 octane

I added CAI, NICHE 19 X 8.5 " wheels with 245/45ZR 19 rubbers, and completely rebuilt the front end with poly bushings, Kooks headers, 2 1/4inch exhaust, TCI 2200-2400 rpm Stall converter

.PLANS:: engine upgrade, 5.4L 2v stroker, rebuild interior in leather w/ buckets, thinking about turbos

Rev Edward ListerOP

Member since Jan 2012
13 posts
Henderson, NV, USA
1 vehicle in the registry

Jan 17, 2012 at 7:40 PM

I don't want to "split hairs" here but I did some research, and found a formula that people might find helpful. Granted, the differences in HP are Very small, for those who want to squeeze every single HP down to the rear wheels, here is the guideline.

Amps x Volts= Watts
Watts / 745.7 (or 1HP) = Electrical HP Produced by Alternator
HP x 15% Efficiency Loss = HP Loss
HP + HP Loss = Total HP Used

EXAMPLE

200A x 12V =2400 Watts
2400W / 745.7 = 3 HP
3 HP x 15% =0.45 HP loss
3 + 0.45 = 3.45 HP Used (I think a TINY amount of this can be reclaimed with an overdrive pulley)

Rev. Edward Lister

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