Alt Upgrade

[Jnthn_Sctt]

Coming up on my 120K maintenance. In addition to the regular timing belts / water pump / fluids etc. Planning on new radiator, curtesy of Chris (custom aluminum) with silicon hoses (thanks Dayle) and undersized pulley, (also curtesy of dayle).

My questions are these:

I'm planning on having my alternator rebuilt at the same time to get more amperage out of it. How high should I go? (Consider I'll have an undersize pulley in it when done, and plan on putting an amp and subs in, in the near future)

Also, what else should I have done at that time?

Thanks in advance,

Jonathan

[lee]

I don't know if the warning I'm going to give is in the nature of a fact, but it's something I've been told, so take it for what it's worth.

Bosch hi-output alternators typically provide more current than the OEM. However, hi-output alternators also produce LESS current at idle (in the nature of no such thing as a free lunch - this is the topic that I might have an "old wife's tale" floating around inside my head). Bosch's answer is to put a slightly undersized pulley on their hi-out models (which is the exact opposite from an undersized pulley on the crank) to keep up the charging rate at low speeds.

So, if you go hi-output and undersized pulley, then run big amps, maybe a light kit...at night, while idling in a parking lot....

Again, this is what I've been told and may not have a speck of truth in it. But before going this route, I think you should ask some questions at an auto electric shop.

[oab_au]

There are only three ways to increase the output. 1. Thicker wire in the stator to cause more amps to flow. 2. A lower resistance rotor, to increase the magnetic flux. 3. Spin the rotor faster to increase the voltage.

The confinds of the alt casing restrict the wire size and number of turns. The smaller pully to pick up the revs sounds like the best way of getting the output where you need it.

Harvey.

[Pure_Insanity8]

I would think manufacturers could make a higher output alt usable for the SVX apllication without needing to spin it faster... I mean it isn't TOO confined space-wise where it is (is it?). Spinning it faster I would think would cut down on its ;ongevity quite a good bit.

They usually get higher outputs at high revs by connecting the stator windings in the "delta" configuration instead of the more user-friendly wye configuration. I have been wondering who makes a good high output alt. that is also connected in the wye configuration, myself.

[oab_au]

Originally posted by Pure_Insanity8
I would think manufacturers could make a higher output alt usable for the SVX apllication without needing to spin it faster... I mean it isn't TOO confined space-wise where it is (is it?). Spinning it faster I would think would cut down on its ;ongevity quite a good bit.

They usually get higher outputs at high revs by connecting the stator windings in the "delta" configuration instead of the more user-friendly wye configuration. I have been wondering who makes a good high output alt. that is also connected in the wye configuration, myself.

Yes well he is going to fit an undersize crank pulley. So the increase in speed will only get it back to square. one.

When they talk about a 'higher output', it can be more amps flowing at the same revs, or it can be a higher voltage, at the same revs.
If the winding wire is thicker, more current can flow, but the thicker wire takes up more room, in the casing, and won't help at low engine revs.
If the voltage is raised, the alt will reach a charging voltage at a lower revs. This can be more usefully as it will do more charging at the lower revs that the traffic allows.

A Delta connection puts the windings in parallel for a higher current flow. The Wye connection puts the windings in series, for a higher voltage. This allows the alt voltage to rise above the battery voltage, at a lower rev, to start charging the battery earlier.

Our alt has a Wye that has the center tap rectified also, along with the phases.

Harvey.