Well i am curious if a bigger alternator could reduce HP. the only way i can see it happening, is if the pulley is bigger or something but other than that, it shouldnt matter right?

i know it will only supply votage better, but just wanted to make sure!

thanks

of course it will cause a decrease in power.

All an alternator does is turn rotational energy into electrical energy. Stock alternate is like 14.4 volt with a peak of 90 amps, that is 1296 watts of electricity. But because no man made device is 100% effcient is actually takes more than 1296 watts of power (750 watts= 1 hp, but we all know we lose more than 2 hp to the alternator=inefficient beast). An alternator that makes more energy will take more power to do it.

An alternator, isn't as easy to spin as you think, the input shaft spins a magnet that create current in the alternator, but this current also creates a magnet field, making is harder and harder for the magnet to spin. This is of course in addition to the other resistances in the alternator (rotational mass, friction).

So basically, yes more powerful alternator equals bigger power drain. If you are lucky though the new alternator might be more efficient and you lost might not be as big as you expected.

p.s. This in not turbo related

^ Yup. The alternator creates it's own "drag" to produce the power it need, by way of the magnetic field. So a higher output alternator will take more power to make more electrical current. The extra power to run accessories or run ignition I don't see offsetting the amount of drain caused.



15.9 @ 86.7mph

Injen CAI, 55mm TB, P&P Intake, Crower Cams, Hooker Header, ERT/Catco Cat, GS-T Muffler, AFX UDP, Crane Ign Amp, S-AFC

I don't think it will put any drag on the car. If anything, it should help with the extra amp it puts out.

I just ordered a bigger alternator this week. It should be at my door today and then be installed in the car tomorrow. I don't think I will see much of a noticeable difference, if any, in power. Time will tell.


The alternator I purchased has 65 amps at 800 rpm and 135 amps at 1900 rpms (this is much higher than our 90 amp peak stock altenator). It should do the job nicely for my new stereo system as well as power all my other equipment without putting a strain on the car.


If any of you are interested, this altenator cost $200 from www.4alterstart.com (thanks to spl eclipse for the recommendation). It also is designed not to harm your current electronics and be a drop in replacement with no modifications needed.


Hope this helps,
Kurt

Yep, unless you have a big stereo system or ALOT of neon lights, your stock alternator is fine. I need one cause I have a kick ass system. As for power loss, you are losing more power but you won't really notice it. 135 amp alternator pulls like an additional ~2 hp, no way you or anyone else will notice, but the question was will there be a lost and the answer is yes. Alternators don't make electricity out of thin air.

Cool... thanks guys... the only reason i decided to post in here about it, was because you the people that come in here seem to have more technical knowledge about this stuff, so i was hoping for the responses i got!


thanks again :thumbsup